Preface - University of · PDF filePreface 2004 was an ... The reader is further referred to the annual report for more details on the research ... cyclotron was later closed and EMC1

Preface

2004 was an especially difficult year for the KVI. Early in 2004 FOM (Foundation for FundamentalResearch of Matter) brought out a concept of its strategic plan for the coming five years that didnot bode well for the institutes and in particular not for the KVI. In order to reserve funding for anew programme (Industrial Partnership Programme) that it found necessary to establish because ofpolitical pressure to stimulate what is now known as “knowledge-based economy”, FOM decided to cutits financial support to the institutes and fundamental research. For the KVI, the absolute financialcut that FOM applied meant a reduction by more than 50% of the total FOM contribution to KVIfunding, which in turn translates to about 20% of the total KVI budget. This severe cut, which is notbased on an evaluation or review of the KVI, would have severe consequences for the personnel if nosubstitutional funding could be found. The University Board of Governors, who supports a KVI witha strong undiminished research programme, has stepped in to give the KVI enough time to find alter-native funding that would keep its research potential intact, though possibly with a different mission.The KVI staff is now orienting itself towards possible involvement in astroparticle physics, neutrinophysics, biophysics and applications of nuclear and atomic physics in various interdisciplinary fields ofresearch and in industry. The KVI is thankful for the RuG Board of Governors for this strong supportand for its trust that KVI personnel would find ways to get extra funding and keep a vigorous andvibrant institute. We are sure we will be up to the challenge in spite of the difficult times ahead, andhope not to disappoint the RuG Board in this respect.

In the following some of the scientific highlights and important events are reviewed in this preface.The reader is further referred to the annual report for more details on the research output in 2004.

The shutdown period in the beginning of 2004 was used to install the TRIµP magnetic separator andto prepare the new electromagnetic extraction channel EMC1 for installation in AGOR. After somesuccessful tests, EMC1 was built into AGOR in March and tested up to the nominal currents. Thecyclotron was later closed and EMC1 was tested at the highest magnetic field (4.1 Tesla) that couldbe reached with AGOR. This paved the way for extraction of lead beams for TRIµP experiments.In April, several heavy-ion beams were developed including a 208Pb26+ beam which was successfullyextracted after acceleration to an energy of 8 MeV/u.For TRIµP a number of milestones was reached in 2004. The separator was tested with beamsfrom AGOR which demonstrated that it fulfils all design specifications. Neon beams were transportedthrough the separator and the reaction products could be nicely separated. 21Na was firstly completelyseparated and with enough quantity to make a β-decay experiment in collaboration with French col-leagues possible. For this experiment a hydrogen target built by the group of Albert Young from NorthCarolina State University was commissioned successfully. The gas-filled mode of the TRIµP separatorwas successfully commissioned with lead beams later in the year. In the TRIµP optical laboratoryprogress was made on barium spectroscopy, in anticipation of measurements with radium isotopesseparated with TRIµP. An important lifetime measurement in barium was successfully performed.A few noteworthy successes have been accomplished in 2004. The experiment to study entanglementof proton pairs was successfully tested with making correlated proton pairs in the 12C(α,2He) reactionyielding results beyond preliminary expectations. Measurements of the TU Darmstadt group in whichthe Clover γ-detectors of KVI were used in coincidence with BBS yielded beautiful results on theexcitation of dipole strength near the neutron-decay threshold. Several irradiation experiments wereperformed at the Multi-User Facility: rats for radiobiology experiments with groups from the MedicalFaculty and the University Hospital; GEM detectors with the group from TU Delft; and determinationof characteristics of scintillator materials with a group from Gießen. The scientific programme of

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AGOR for 2004 was concluded with successful tests of the new BINA detector.We also had several setbacks with running the scientific programme in 2004. The tests with thethermo-ionizer for TRIµP did not yield any definite results. Later in the year, the new EMC1 devel-oped short circuits in two of the coils in spite of the careful isolation. Also, one of the wire chambers ofthe BBS polarimeter had broken wires which required sending the detectors to TRIUMF, Vancouverfor reparation. This led to cancellation of the experiments planned with the BBS in the autumn.

The nuclear physics application ‘Integrated Infrastructure Initiative for EUROpean Nuclear Structure(EURONS)’ in the EU 6th framework Programme was approved in April after having been put on thereserve list the year before. The KVI is involved in all aspects of the programme: ‘Transnational Ac-cess’, ‘Joint Research Activities’ and ‘Networking Activities’. Furthermore, FINUPHY, the European“Infrastructure Cooperation Network” in the EU 5th framework Programme, requested and receiveda prolongation of its contract with a period of six months starting 1 October 2004. The KVI receivedmoney to organise a workshop in March 2005 on detection systems for electromagnetic radiation.Also, the midterm evaluation of the NGD project in the EU 5th framework Programme, NuPulse,which took place early in 2004, was positive. NuPulse was recognised by the EU representative as anexample where Europe can play an important world-market role.

The collaboration between the Dutch road-construction contractor Heijmans and NGD with respectto the use of non-invasive radiometric techniques for determination of the layer thickness of road as-phalt was intensified last year and extended to measurement of pollution of ZOAB asphalt and alsoto clearing of landmines making use of the PELANIII detector.

The KVI organised or helped organise several meetings and workshops in 2004.

• A farewell symposium was organised for Lex Dieperink on 27 February.

• Together with the nuclear physics divisions of Austrian, Belgian and German Physical Societies,a joint Spring meeting was organised in Koln from 8 to 12 March. One of our graduate students,Moslem Sohani, won the second poster prize.

• Another farewell symposium was organised for Siebren van der Werf on 2 April with the title“Once upon a time....”.

• On Thursday 8 April the KVI acted as a host institute for the programme of presenting the Jan-Kommandeur prize to high-school students who won the competition for technical innovativeprojects.

• A festive gathering and workshop was organised in Orsay on 27 and 28 May to celebrate 10 yearsof AGOR operation.

• On Saturday 12 June, a get-together for the KVI alumni was organised at KVI. This is thesecond in a series, where the alumni visit the KVI and are kept up to date on the scientific andorganisational developments.

• The 19th European Conference “Few-Body Problems in Physics” was held in the congress centreMeerwold in Groningen in the period 23-27 August. It was a successful conference with morethan 170 participants.

• The KVI opened its doors to many visiting groups in 2004, and organised an open day on Sunday,24 October in the framework of the National Science Week with the theme of this year “Use yourbrains” (Gebruik je hersens). It was again a very successful open day with around 580 visitorsand the local press.

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We have had a number of mutations in the personnel sphere in 2004.

• In 2004, the RuG Board of Governors approved the KVI appointments of Ronnie Hoekstra andNasser Kalantar-Nayestanaki as adjunct-professors and Rob de Meijer and Hans Wilschut asspecial (bijzonder) professors.

• Furthermore, Lorenz Willmann and Heinrich Wortche were promoted from assistent (universitairdocent) to associate (universitair hoofddocent) professors. Johan Messchendorp’s position waschanged to permanent assistant professor (universitaire docent).

• Herbert Lohner was appointed by the Board of the Faculty of Mathematics and Sciences asDirector of Physics Education in September 2004 for a period of three years.

• Six graduate-student positions in the various KVI groups were filled in 2004. Furthermore, twopositions have been filled in two of the technical departments at KVI. On the other hand, twosenior staff members and two staff members on fixed-term positions left us in 2004.

We had six Ph.D. graduations in 2004: Marc de Huu, Vladimir Kravchuk, Danyal Winters, ZoltanJuhasz, Masoud Mahjour Shafiei and Dan Cozma. All got positions in academic research and inindustry. This is a very good result for the KVI compared to other years.

Marc van Veenhuizen received for his master’s thesis research in the Theory Group the 2004 Kamer-lingh Onnes prize.

In 2004, FANTOM organised two study-weeks. The first of these general study-weeks was organisedin the week 24-28 May in Emmen, the Netherlands with the title: “QCD at low energies”. The secondstudy-week on the topic: “Symmetries and Symmetry Violation” was held in Gent, Belgium in theweek 15-19 November.In June, we received the news that the application of FANTOM for renewed recognition by the RoyalDutch Academy of Sciences (KNAW) as an international research school was honoured for a periodof six years.

The Programme Advisory Committee (PAC) of KVI met on November 26-27, 2004. The membersof the PAC are: J. Aysto (University of Jyvaskyla), R. Calabrese (INFN, Ferrara), Ph. Chomaz(GANIL, Caen), S. Gales (IPN, Orsay), O. Naviliat-Cuncic (LPC, Caen), L. Nilsson (TSL, Uppsala;chairman), H. Sakai (University of Tokyo) and H. Stroher (FZ, Julich). The PAC considered 9 newproposals, 3 re-submitted proposals and 2 letters of intent that were submitted. Considering the avail-able beam time in 2005, which is much less than the requested one, the PAC allotted much less beamtime than requested. Furthermore, the PAC reviewed the status of the facility and was satisfied withthe progress made with TRIµP and the improvements on AGOR. It also expressed its dissatisfactionand unhappiness with the way FOM has cut the KVI research budget.

The “Beleidscollege (BC)” (policy-advisory board) of KVI, which advises directly the Board of Gov-ernors of the University of Groningen (RuG) and the Executive Board of the funding agency FOM,consisted in 2004 of K. Bulthuis (FOM), D. Guerreau (IN2P3), M.A. Kooyman (RuG; chairman),G. Luijcks (NIKHEF), P.J.G. Mulders (VUA), W.J. van der Zande (RU) and S. Daan (RuG). G.A.Mulder (RuG) and J. de Kleuver (FOM) served as first and second executive secretaries of the BC.The BC met on 25 January. The meeting was completely dedicated to the problems that threatenedto arise as a consequence of the new FOM policy regarding fundamental research in general and nu-clear physics in particular. It was clear from this meeting that FOM was about to reduce its financial

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commitment to KVI research programmes (see above).

We have had many visitors for longer or shorter periods in 2004, who contributed to the scientificprogrammes of the KVI. Two of them received scholarships from NWO (The Dutch Organisation forScientific Research) and stayed at KVI for long periods. I would like to mention in particular Profes-sor Czaba Korpa (Pecs, Hungary) who stayed at KVI for three months, Dr. Herwig Ott (Florence,Italy) who stayed for six months starting October, Dr. Kurt Gloos (NBI, Copenhagen, Denmark)who stayed for two months starting middle of November, and Mr. Setsuo Tamenaga, a graduatestudent from RCNP Osaka, who stayed for three months. Furthermore, I would like to acknowledgeNWO also for the financial contributions to stimulate exchange programmes with France and Hungary.

Finally, I thank the KVI scientific and technical staff, the colleagues from the various collaborationsand institutes and the many guests for their valued contributions to the scientific activities of KVI in2004.

Groningen, March 2005 Muhsin N. Harakeh

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Contents

1 TRIµP 91.1 Status of the TRIµP program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101.2 Precision measurement of the GT branching ratio in 21Na decay: Feasibility test at

TRIµP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111.3 First tests of the separator in gas-filled mode. . . . . . . . . . . . . . . . . . . . . . . . 121.4 Installation and Commissioning of the Dual Magnet Spectrometer for TRIµP . . . . . 131.5 Isotope shift in heavy alkaline earth metals . . . . . . . . . . . . . . . . . . . . . . . . 141.6 Development of a Polarimeter for the Search of a Permanent Electric Dipole Moment

of the Deuteron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151.7 Radio-frequency cooler and low-energy beam line for TRIµP . . . . . . . . . . . . . . 161.8 A gas target for production of a secondary radioactive beam with the TRIµP separator 17

2 Experimental nuclear physics 192.1 Few-body physics activities at KVI; an overview . . . . . . . . . . . . . . . . . . . . . 202.2 proton-proton bremsstrahlung towards the elastic limit . . . . . . . . . . . . . . . . . . 212.3 Electromagnetic response functions in pp scattering at 190 MeV . . . . . . . . . . . . 222.4 Vector and tensor-analyzing powers in p+d radiative capture . . . . . . . . . . . . . . 232.5 Virtual photon production in proton-deuteron capture reaction . . . . . . . . . . . . . 242.6 First Results on Analyzing Powers of the 1H(d, pp)n Breakup Reaction at 130 MeV . . 252.7 The analysis of elastic H(d, p) reaction at 90 MeV/nucleon . . . . . . . . . . . . . . . . 262.8 Determination of vector and tensor-analysing powers in elastic deuteron-proton scattering 272.9 Status of BINA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282.10 Nucleon-resonance decay through the K0Σ+ channel . . . . . . . . . . . . . . . . . . . 292.11 Nucleon-resonance studies on the deuteron . . . . . . . . . . . . . . . . . . . . . . . . . 302.12 Radiation damage in large-area avalanche photodiodes . . . . . . . . . . . . . . . . . . 312.13 Measurements of the 28Si(p,t)26Si reaction to determine rates in the stellar rp-process 32

3 Theory 333.1 Covariant Rarita-Schwinger propagator in the nuclear medium . . . . . . . . . . . . . 343.2 The nucleon-sigma coupling constant in external-field QCD Sum Rules . . . . . . . . . 353.3 P- and T-odd two-nucleon interaction and the deuteron electric dipole moment . . . . 363.4 The Dibaryon resonance and two-photon bremsstrahlung . . . . . . . . . . . . . . . . . 373.5 Neutron-proton mass difference in chiral perturbation theory and nuclear forces . . . . 383.6 KΛ and KΣ photo-production in a coupled channels framework . . . . . . . . . . . . . 39

4 Atomic Physics 414.1 Reduced electronic stopping in laser excited fullerenes . . . . . . . . . . . . . . . . . . 424.2 Ion – biomolecule interactions and radiation damage . . . . . . . . . . . . . . . . . . . 434.3 Charge Exchange in Cometary Atmospheres . . . . . . . . . . . . . . . . . . . . . . . . 44

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4.4 Direct observation of pure one-electron capture from the target inner-shell in low-energyp +Na collisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

4.5 One electron capture and ionization in collisions between highly charged ions and Na . 464.6 Repump-enhanced Single Atom Detection . . . . . . . . . . . . . . . . . . . . . . . . . 474.7 Spin filtering in electron capture from surfaces . . . . . . . . . . . . . . . . . . . . . . 48

5 Nuclear Geophysics 495.1 Earth AntineutRino TomograpHy (EARTH). . . . . . . . . . . . . . . . . . . . . . . . 505.2 Feasibility of a directional sensitive antineutrino detector . . . . . . . . . . . . . . . . 515.3 Geological considerations on the location of the EARTH antenna on Curacao . . . . . 525.4 Monitoring nuclear fuel with antineutrinos . . . . . . . . . . . . . . . . . . . . . . . . . 535.5 Gamma-ray analysis of NuPulse data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 545.6 Benchmark experiments: uncertainties in 16O cross-section data library. . . . . . . . . 555.7 First in-situ experiments with NuPulse tool . . . . . . . . . . . . . . . . . . . . . . . . 565.8 Fast neutron spectra measured at NGD/KVI calibration facilities. . . . . . . . . . . . 575.9 An anticoincidence set-up for the BGO detectors in PHAROS: benchmark experiment 585.10 In-situ sediment gamma-radiation at the barrier island Schiermonnikoog (NL) . . . . . 595.11 Variations in gamma radiometry at a layered salt marsh . . . . . . . . . . . . . . . . . 605.12 Initial design of software for a prototype of a radiometric asphalt layer thickness monitor 615.13 ERRICCA 2, A European radon forum . . . . . . . . . . . . . . . . . . . . . . . . . . 625.14 Monte Carlo determination of electron-photon conversion efficiency in laser experiments 63

6 Miscellaneous 656.1 RIASH: Radioactive Ions and Atoms in Superfluid Helium . . . . . . . . . . . . . . . . 666.2 Meeting report: Fundamental Interactions . . . . . . . . . . . . . . . . . . . . . . . . . 676.3 Status of HISPARC Groningen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 686.4 Neutrino physics: a new research line for KVI . . . . . . . . . . . . . . . . . . . . . . . 696.5 ZESANA: The ZEchstein SAlt Neutrino Array . . . . . . . . . . . . . . . . . . . . . . 70

7 Agor, Ion Sources and Radiation Safety 717.1 Survey of beam time used for experiments with AGOR in 2004 . . . . . . . . . . . . . 727.2 AGOR status report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 737.3 Status of the KVI ion sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 747.4 The new ECRIS upgrade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 757.5 Revision of the AGOR Main Magnet Power Supplies . . . . . . . . . . . . . . . . . . . 76

8 Technical support 778.1 Activities of the Electronics & Electrotechnical Department . . . . . . . . . . . . . . . 788.2 Activities of the mechanical department . . . . . . . . . . . . . . . . . . . . . . . . . . 798.3 Activities of the research technicians . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

9 Publications and Scientific Presentations 839.1 List of publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 849.2 Ph.D. Theses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 909.3 Contributions to conferences, workshops etc. . . . . . . . . . . . . . . . . . . . . . . . . 909.4 Organized Conferences, workshops etc. . . . . . . . . . . . . . . . . . . . . . . . . . . . 979.5 Internal reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 979.6 Seminars at KVI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 989.7 Seminars and colloquia given by staff members outside KVI . . . . . . . . . . . . . . . 100

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10 Personnel 10310.1 Scientific staff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10410.2 Technical and administrative staff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

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Chapter 1

TRIµP

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1.1 Status of the TRIµP program

K. Jungmann

The TRIµP progamme has the aim to in-vestigate with high precision the fundamentalsymmetries and interactions in physics. In par-ticular this includes searching for new physicsbeyond the Standard Model. Two directionsare followed: The first approach is pursued bystudies in β-decay observing the correlationsbetween the β-particle, the recoiling nucleusand eventual spin observables. The second ap-proach is to search for an electric dipole mo-ment (EDM) of particles, such as nuclei andatoms. In both cases radioactive nuclides givea chance to pursue this. Precision measure-ments require atomic cooling to very low tem-peratures, making trapping an essential tool.Trapping also allows one to select, manipulateand collect isotopes. Thus production of iso-topes and trapping of minor quantities of rareatoms are central to the programme.

During the past year we have commis-sioned a newly designed dual separator. As-pects of this work are reported in various con-tributions in this section. The availability ofwell separated radioactive isotopes of some 10MeV/nucleon has allowed us to start an in-termediate experimental programme prior tocompletion of the entire TRIµP setup. Thefirst one concerns a study of some parametersimportant to β-decay (see section 1.2). Theinfrastructure for the various lasers is beingdeveloped in parallel to the experimental pro-gram. Knowledge and equipment are availableto trap alkali atoms such as Na, where 21Na isintended to be the first nucleus to study β − νcorrelations. New is the development of a Mag-netic optical trap for Ba (see contribution 1.5).This will serve as a pilot project to trap ra-dioactive Ra.

At present we concentrate efforts on a de-vice to slow the energetic nuclei at the endof the separator to the energy range where a

newly designed radio frequency cooling device(RFQ) can operate, i.e. typically several eV.After initially investigation the possibility forgas stopping devices as the most generic so-lution, we now favor stopping in a hot solidmaterial and using thermal ionization on a hotmetal surface. This will be the optimal so-lution for alkali and earth-alkali atoms. Thesetup of the RFQ and the beam line lead-ing to the trapping setup are currently underconstruction, as reported in contribution 1.7.We aim to have the first trapping of isotopeswithin the coming year.

A novel method to search for EDM’s hasbeen proposed. It uses charged particles cir-cling in a storage ring. In such a ring themotional electric field can supersede what canbe achieved with static fields using the latestelectronic technology. Preparatory work hasbeen started for the case of the deuteron (seecontribution 1.6). The deuteron has becomeparticularly relevant now that the KVI theorygroup has identified it to have superior sensi-tivity to certain EDM generating mechanismscompared to the more frequently studied neu-tron (contribution 3.3).

Figure 1: View of the TRIµP separator seen fromabove prior to closing the roof. The inset shows animpression of the work in the laser laboratory.

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1.2 Precision measurement of the GT branching ratio in 21Na decay:Feasibility test at TRIµP

L. Achouria), J.-C. Angeliquea), G. Bana), G.P.A. Berg, B. Blank b), G. Canchel b), P.G. Dendooven,J. Giovinazzob), K. Jungmann, E. Lienarda), I. Mateab), O. Naviliat-Cuncica), N. Orra), A. Ro-gachevskiy, M. Sohani, E. Traykov and H.W. Wilschut

This experiment aims to achieve an im-proved measurement of the branching ratio ofthe Gamow-Teller transition in the β-decay of21Na. The accurate knowledge of this quantityis crucial for the interpretation of a recent re-sult on the β-ν angular correlation coefficientmeasurement in 21Na decay [1]. We propose todetermine this branching ratio by measuringthe emitted γ-ray at 351 keV using 21Na nu-clei produced and separated by the new TRIµPfacility. To assess the measuring conditions atTRIµP, a feasibility test has been performed.The main goal was to check the purity and theintensity of a 21Na beam and to measure the in-clusive γ-ray spectrum. A telescope with threesilicon detectors (150mm, 300mm, 4.5mm) wasmounted in a reaction chamber at the end ofthe separator line. A HPGe clover shieldedwith BGO faced the chamber parallel to thebeam axis. The 21Na was implanted in thethick silicon detector. A silicon detector iden-tified the particles at the intermediate focalplane of the TRIµP separator on basis of en-ergy loss and time-of-flight as shown on theleft of Figure 1 on the right is the same spec-trum but obtained by gating on the stoppingdetector. We conclude that the contaminationof the 21Na beam was less than 0.05% and theintensity was of the order of 103 s−1.

Na

NeF

O

Time (a.u.)

En

er

gy

21Na

20Ne

0 10 20 30 40 50Time (arb. units)

0 10 20 30 40 Time (arb. units)

Ene

rgy

(arb

. uni

ts)

0

10

2

0

30

40

5

0

Figure 1: Particle identification in the intermediatefocal plane (see text).

Figure 2 shows the γ-ray spectrum near351 keV. The full spectrum was obtained with-

out any restrictions, the dashed spectrum wasmade requiring an anti-coincidence with theBGO shielding, and the dotted spectrum isthe background. The following important ob-servations can be made: The Compton edgeof 511 keV γ-rays is close to the peak at 351keV. The BGO shielding improves the sig-nal/background ratio. The background spec-trum shows a peak at 351 keV correspondingto natural radioactivity from the 238U series(351.9 keV in 214Pb). A preliminary analy-sis shows that in order to measure preciselythe 351 keV γ-ray yield from 21Na decays, weneed to describe the Ge response to a 511 keVphotons very accurately and measure the back-ground with high statistics. In conclusion, thetest appears to prove the feasibility of this ex-periment. Some of the main points need to beimproved upon.

300 340 380 (Eγγ keV)

0

50

0

1000

1500

(co

unts

)

Figure 2: γ-ray spectra near 351 keV under variousconditions (see text).

a) LPC, 14050 Caen, Franceb) CENBG, 33175 Gradignan, France[1] N.D. Scielzo et al., Phys. Rev. Lett. 93,

102501 (2004).

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1.3 First tests of the separator in gas-filled mode.

A. Rogachevskiy, G.P.A. Berg, U. Dammalapati, S. De, O. Dermois, P. Dendooven, K. Jungmann,E. Traykov, M. Sohani, L. Wilmann, H.W. Wilschut

One of the requirements of the TRIµPproject is the production of short-lived ra-dioactive nuclei with high element number.They can be used for example to search forthe forbidden electric dipole moment (EDM).For that particular purpose 213Ra is a goodcandidate since it has possible enhancementsof the EDM signal due to its atomic struc-ture. Fusion reactions can be used to produce213Ra. We use a 206Pb beam and a 12C target.This inverse kinematics allow one to get 213Rarecoils out of the target. To separate fusionproducts (213Ra) from the beam and fissionfragments, the “gas-filled” mode of the TRIµPseparator is used. In this mode the first partof the separator serves as a beam line and thesecond part as a recoil separator. The gas inthe separator causes particles to move along atrajectory with an effective average charge. Italso introduces additional differential stoppingto separate beam and recoils further. The vac-uum and gas-filled sections are separated bya 2.5 µm Havar foil. Typically a few mbar ofargon gas was used.

An experiment was performed to commis-sion this mode. The aim was to observe howwell one can collect the different charge statesin a single peak in the focal plane and to com-pare this result with theoretical calculations[1].

In this experiment we used a 8.4 MeV/u206Pb29+ beam. By passing through the Havarfoil the beam is stripped to a distribution ofcharge states centered near 60+. The targetwas a 4.2 mg/cm2 thick 12C foil. First we ob-served the maxima of the charge state distri-bution of the beam particles without gas fill-ing (the square symbols in Figure 1), using amovable scintillator screen in the focal plane.With a modified Faraday cup, the widths of theindividual states were measured to be 2.5 cm(0.4% in Bρ) as indicated for two states in Fig-

ure1 by the full curve. After filling the systemwith 2.5 mbar of argon gas and adjusting themagnet settings we observed the beam as asingle peak in the focal plane. The result isshown as the dotted curve in Figure 1 whichwas scaled to coincide with the highest peak.The width of the peak is 8 cm (1.3% in Bρ).The observations are in good agreement withthe predictions simulated in [1].

We found radioactivity in a movable Sili-con detector that was used to scan the focalplane. The observed radioactivity indicatedthe production of long-lived daughters of Ra.However, the current diagnostic tools, the lim-ited beam intensity and the uncertainty of thebeam energy did not allow us to identify theproducts in more detail. For 213Ra productionfurther development experiments will be nec-essary.

Bρ (arbitrary units)

Yie

ld (

arbi

trar

y un

its)

0

0.2

0.4

0.6

0.8

1

1.2

1.4

140 145 150 155 160 165 170 175 180

Figure 1: The square symbols indicate the position ofa maximum in the collected current. The full line de-notes the measured line shape of two of the charge statepeaks. The dotted line is the line shape observed withgas filling

[1] O. Dermois KVI Annual report, 26 (2001).

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1.4 Installation and Commissioning of the Dual Magnet Spectrom-eter for TRIµP

G.P.A. Berg, O. Dermois, U. Dammalapati, S. De, P. Dendooven, M.N. Harakeh, K. Jungmann,H. Kiewiet, C.J.G. Onderwater, F. Rengers, A. Rogachevskiy, J. Sijbring, L. Slatius, M. Sohani, E.Traykov, L.Willmann, H.W. Wilschut

The TRIµP dual magnet separator is oneof the important parts in the equipment chainof the TRIµP facility. Its role is to separatethe desired isotopes from the primary beamand from other reaction products. By the endof the year 2003 all magnets and major com-ponents of the TRIµP separator were procuredand installation had started as reported in theprevious KVI Annual Report. Installation con-tinued during the beginning of this year andwas completed in May 2004, in time for thefirst scheduled commissioning and test runs.All magnets were installed, aligned and con-nected to their power and cooling water sup-plies. The vacuum chambers and pump sta-tions were installed and leak tested. A largesurplus vacuum chamber T3 was equippedwith a movable table and installed in the fi-nal focal plane to allow commissioning tests.For diagnostic, setup and optimization proce-dures a number of devices where procured andinstalled at appropriate locations in the sepa-rator. These include harps, viewers, Faradaycups, and slits with current readouts. Solidstate detectors were installed in the intermedi-ate (T2) and the final (T3) chamber for parti-cle identification using energy loss and time-offlight information obtained from these detec-tors. In addition a wedge/degrader is avail-able in T2 to improve particle separation inT3. During commissioning a 43 MeV/nucleon21Ne7+ beam with a magnetic rigidity of Bρ= 2.86 Tm was transported through the sep-arator system to verify the ion-optics of thefragment mode. In order to verify the mo-mentum dispersion and to obtain informationabout the momentum acceptance, copper foilsof 7.5, 15, and 22.5 µm where inserted at thetarget location T1. The momentum loss of the22.5 µm foil was 1.0%. The beam consistsof fully stripped 21Ne10+ ions after the tar-get. The momentum dispersion measured inthe dispersive focal plane (T2) was 4.2 cm/%

corresponding to 2.1 cm/% energy dispersionin non-relativistic approximation. This is inagreement with the design calculations. A cir-cular beam spot of about 2 cm FWHM wasobserved in the achromatic final focal plane(T3). The ion-optics for the gas-filled modewere tested by transporting the 21Ne7+ beamonto the target T2. Without gas-filling the mo-mentum dispersion in the final focal plane wasmeasured by inserting the copper foils and us-ing the method mentioned above. The result-ing momentum dispersion of 6.9 cm/% is inagreement with the design calculations.

After successful commissioning and veri-fication of ion-optics and design parameters,we produced 21Na using the (p,n) reactionin inverse kinematics using a 21Ne beam at43 MeV/nucleon. A 20 mg/cm2 polyethy-lene (CH2)n foil was used as hydrogen target.The emerging 21Ne10+beam with a magneticrigidity Bρ about 9% higher than the desired21Na10+ isotopes is stopped in a movable beamstop between the first dipole magnets BT1 andBT2. Momentum cutting slits in T2 were usedto reduce background. An active absorber inthe form of a 0.1 mm thick Silicon detector wasused to further clean up the 21Na isotopes inchamber T3. This 21Na beam was later used ina first experiment to study the β-decay branch-ing ratio in 21Na (see contribution 1.2).

In July we commissioned a LN2 cooled hy-drogen gas target that was designed and builtin collaboration with a group from TUNL,North Carolina, USA. It is described in contri-bution 1.8. Beam currents were tested up to300 enA of 21Ne. Finally, a first test was con-ducted toward producing 213Ra using a 206Pbof 8.6 MeV/nucleon and a 12C target. Usingthe gas-filled mode, we verified the collectionof about 10 charge states into a spot of 8 cmwidth at a gas pressure of 2.5 mbar Ar gas fill-ing as reported in contribution 1.3.

13

1.5 Isotope shift in heavy alkaline earth metals

U. Dammalapati, S. De, G. Ebberink, K. Jungmann, L. Willmann

A sensitive test for the validity of the stan-dard model is the investigation of discrete sym-metries like charge conjugation (C), parity (P)and time (T). In particular, a nonzero perma-nent electric dipolemoment(EDM) of a funda-mental particle violates P and T at the sametime. A fundamental EDM can induce a muchlarger dipole moment in composite objects likeatoms. The radioactive alkaline earth elementradium, which will be soon be available withinthe TRIµP facility, appears to be a promisingcandidate [1,2]. Available spectroscopic dataon radium indicate an energy difference of only5 cm−1 between 3P1 and 3D2 states of oppo-site parity, causing a large enhancement of theatomic EDM in this state. As a first step wewill confirm the energy splitting between thesestates. At a later stage we need to laser cooland trap radium.

-5 0 5

0.6

0.8

1.0

Dep

leti

on

105 110

0.6

0.8

1.0 136Ba

1750 1755 1760

0.6

0.8

1.0

135Ba (F=5/2)

138Ba

[MHz]

Dep

leti

on

[MHz]1895 1900 1905

0.6

0.8

1.0

137Ba (F=5/2)

Frequencies relative to 138Ba

Figure 1: Examples of the intercombination linefor different barium isotopes measured by the optical-optical double resonance technique.

In preparation for our work with radium weinvestigate stable barium isotopes, which havea level scheme similar to radium. In particu-lar, we develop the spectroscopic tools to de-termine energy levels, hyperfine structure andthe lifetime of the metastable 3D-states. Thesemeasurements reveal important insights in theatomic structure of the heavy alkaline earth el-ements and are indispensable for atomic struc-ture calculations, which are needed to calculatethe atomic EDM in radium.

In barium we observe the hyperfine struc-

ture of the 3P1 state by an optical-optical dou-ble resonance technique. The strong 1S0 - 1P1

transition is resonantly excited by a dye laserat 553.7 nm. At the same time we tune adiode laser to the weak 1S0 - 3P1 intercombi-nation at 791.35 nm. The absolute frequencyof the diode laser is determined by comparingit with the ’a1’ line of the hyperfine structureof the P(52)(0-15) transition in molecular io-dine I2. The intercombination line is detectedby a decrease in the fluorescence of the 1S0 -1P1 transition, because of the depletion of thecommon ground state 1S0. The advantage ofthis method is the high sensitivity because ofthe detection via the strong transition. Thisis important for the design of the experimentwith rare radium isotopes.

Isotope 1S0-3P1(MHz) 1S0-1P1(MHz)137 185(4) 215.15± 0.16136 108.5(3) 128.02± 0.39135 221(4) 259.29± 0.17

Table 1: Isotope shift of the 1S0 - 1P1 and 1S0 - 3P1

relative to 138Ba

The measured hyperfine structure agreeswell with previous microwave determinations.Using the known hyperfine structure splittingwe determine the isotope shift of the intercom-bination line. The technique used for this ex-periment will be useful to determine the rel-evant numbers in the radium atom, once theisotope is available in quantities at the TRIµPfacility.

Presently, we are investigating laser cool-ing and trapping of barium, an atom whichhas never been laser cooled so far. The strong1S0 - 1P1 serves as the main cooling transition.In addition, we employ three lasers for the re-pumping at 1108 nm, 1130 nm, and 1500 nmto provide a closed level system.

[1] V.A. Dzuba et al. Phys. Rev. A 61, 062509(2000).

[2] J. Bieron et al., J. Phys. B: At. Mol. Opt.Phys. 37, L305-L311 (2004).

14

1.6 Development of a Polarimeter for the Search of a PermanentElectric Dipole Moment of the Deuteron

C.J.G. Onderwater, E.J. Stephensona), G. Noida)

Tests of the Standard Model are motivatedas a way to locate new physical processes. Onesignature of such new processes is an intrin-sic electric dipole moment (EDM) at a levelsomewhat beyond the reach of completed ex-periments. The dEDM Collaboration[1] hasbeen investigating the possibility of searchingfor an EDM on charged particles with a mag-netic storage ring[2]. An EDM would be visiblethrough a vertical spin precession component.The deuteron is an excellent candidate for sucha search, both theoretically[3] and experimen-tally.

The polarimeter needed to monitor thespin must be efficient and capable of samplingthe polarization of the circulating beam con-tinuously. In the present design a thin (gasjet) target is used to spread the beam throughsmall angle Coulomb scattering. Downstream,the outer fringes of the beam intercept a thickannular carbon target. It is the nuclear scat-tering from this second target that is the activeelement of the polarimeter. The thickness en-sures that the measurement has high statisticsand will be as efficient as possible. A feasibil-ity study for an adjustable-size annular carbontarget is nearing completion (HTS afstudeer-project of G. Mul). The dynamics of the targetand the resulting compromises in the design ofthe target are an integral part of the design ofthe polarimeter as a whole.

In preparation of a full proposal, the col-laboration has fixed the deuteron kinetic en-ergy at 126 MeV. At this energy, we expectthat the effects of ”rainbow scattering” arelarge enough that one can design a polarimeterwith a large figure of merit. In October 2004,with help from the KVI staff[4], we have mea-sured the cross section and analyzing power forall singly-charged particles that emerge whena deuteron beam hits a carbon target. Datawere accumulated at 80 and 110 MeV, two en-ergies that span the range from 60 to 126 MeV

over which the annular target will operate. Apreliminary analysis shows the expected largeanalyzing powers (see Figure 1). On the basisof these data, we will simulate the polarimeterdesign and optimize its figure of merit. Sev-eral performance characteristics will be testedat KVI with a prototype polarimeter [4]. Fi-nal testing would need to be done at a stor-age ring where the interaction of the polarime-ter with the circulating beam could be stud-ied. A Letter-of-Intent has been submitted toCOSY/Julich in April, where such beams areavailable.

Deuteron Energy [a.u.]200 300 400 500 600 7000

0.2

0.4

0.6

0.8

1

Rate

iT11

° = 57labθ

T = 80MeV

Figure 1: Preliminary analysis of the relative rate andanalyzing power for the 12C(d, d′)X channel as a func-tion of the scattered deuteron energy.

[1] for a list of collaborators, seehttp://www.bnl.gov/edm/

[2] F.J.M. Farley et al., Phys. Rev. Lett.93, 052001 (2004); Y.K. Semertzidis et al.,CIPANP03 proceedings (Intersections con-ference in NYC), hep-ex/0308063;

[3] C-P. Liu and R.G.E. Timmermans, this report,contribution 3.3.

[4] G.P.A. Berg, U. Dammalapati, S. De. K. Jung-mann, J. Messchendorp, A. Rogashevsky,M. Shohani, E. Traykov, H. Wilschut, H.Wortche, KVI proposal P04, Nov. 2004

a) IUCF

15

1.7 Radio-frequency cooler and low-energy beam line for TRIµP

E. Traykov, O. Dermois, L. Huisman, K. Jungmann, J. Mulder, L. Willmann, H. Wilschut

the radio frequency quadrupole cooler (rfq-cooler) and the low-energy beam line, play acentral role in the TRIµP facility, to distributethe isotopes to the experimental setups. Afterselecting the isotopes in the TRIµP separatorthey will be slowed down and collected by athermoionizer or a gas cell. The isotopes areextracted as ions from these devices in orderto allow that they can be further purified andeasily transported using ion beam optics. Therfq-cooler is designed and the parts have beenproduced at KVI. A drift tube accelerator andelectrostatic beam guiding system is being setup.

The radio frequency quadrupole is based onour prototype design utilizing capacitive cou-pling of the rf to the segmented electrodes,which allow for a position dependent dc po-tential along the axis [1]. The rfq-cooler con-sists of two identical rfq units separated by asmall pumping aperture. In the first rfq ionsare cooled by an appropriate buffer gas with apressure of around 10−2 mbar. The fine seg-mentation along the axis provides the possi-bility of confinement in all three dimensions.This will be used to accumulate ions and thenextract them in a pulse by switching the po-tential on some of the segments. After the rfqthe ions will be accelerated to several keV in adrift tube and guided into an all electrostaticlow energy beam line. The drift tube acceler-ator allows us to keep the rfq as well as thelow-energy beam line at ground potential.

We have performed a detailed calculationof the rfq. The electric fields, dc as well asac parts, have been calculated using FEM-LAB [2]. Special attention has to be paid tothe fringe fields at the entrance and the exitin order to optimize the coupling into the rfqand the subsequent extraction. The calculatedfields are used for tracing ions trough the rf-structure. An example of such a calculation isshown in Figure 1.

The first part of the rfq-cooler has been

built. It is 330 mm long and it has 36 segmentsalong the axis. The radial separation betweenthe electrodes is 10 mm. As a first test welooked at the transport of Cs ions. We usea micro-channel plate (MCP) detector with aphosphor screen to detect ions 10 mm behindthe rfq. Depending on the rf voltage on theelectrodes the emission pattern changes. Theobserved pattern is in good agreement with ournumerical simulations (Figure 1). The MCPwill be used later as a diagnostic tool in thelow-energy beam line.

Measurements of the emittance of the rfqare an important input for the design of thedrift tube accelerator. The calculations usingthe FEMLAB package as well as position sensi-tive measurements of the ions provide a helpfultool for this task.

Figure 1: Top plot: calculated positions of ions at theend of the rfq (blue dots) and 10 mm behind the rfq(red dots). The shape changes from a round focussedspot to a cross reflecting the four fold symmetry of therfq when the rf voltage is changed. Lower plot: Obser-vation of the position of ions 10mm behind the rfq witha micro channel plate detector. The shape is changingas expected from the calculation.

[1] E. Traykov et al., KVI Annual Report, 41(2003).

[2] www.consol.com

16

1.8 A gas target for production of a secondary radioactive beamwith the TRIµP separator

A.R. Younga) M. Boswella) G.P. Berg, A. Rogachevskiy, M. Sohani, E. Traykov

We have constructed a LN2 cooled gas tar-get, primarily for H2, D2 and He gases, to becoupled to the TRIµP mass-separation system.The design goals of this system were to be com-patible with the typical beams and inverse re-action dynamics to be utilized by the TRIµPcollaboration: beam powers of up to 1 kW,beam dimensions of a few mm or less, and aminimal window thickness, but the target it-self should be able to support at least 1 atmof 80 K target gas. The system must alsobe able to translate vertically upward roughlysufficiently to permit beam tuning and to allowthe utilization of other target systems.

These goals are met by a design in whichthe target is immersed in LN2, in a stainlesssteel dewar. The target itself is 10.7 cm long,with entrance and exit windows 1.25 cm in di-ameter. The 2.5 µm HAVAR foils we are usinghave been demonstrated to be leak free whenuseful beam intensities are directed at the tar-get (the maximum beam to date has beenabout 300 enA of 21Ne at 43 MeV/nucleon).The entrance and exit windows are eithersoldered or glued onto a Cu conflat-flangeand clamped between standard conflat flangesmounted on the entrance and exit of the target.

Hydrogen gas is introduced through0.64 cm diameter tubing into the target cell(and can be circulated through a separate ex-haust line separated by about 6 cm). The gasis cooled as it is introduced to the cell throughthe LN2 dewar and through contact with theCu walls of the cell (roughly 2 cm in diame-ter). The target is raised and lowered usinga Thermionics vertical jacking stage with a 15cm vertical stroke and a 15 cm ID. The overallheight of the target unit is 75 cm. The overallsetup is shown in Figure 1.

The use of the gas target has two im-portant benefits compared with solid targets.First, polyethylene targets used in the firstcommissioning phase showed rapidly diminish-ing hydrogen content at a few tens of enA.Second, in the magnetic rigidity region wherethe 21Na yield from the charge-exchange re-action 1H(21Ne,21Na)n is maximal, contribu-tions from other fragments are strongly re-duced when using the gas target.

beam

gas cell

LN2 dewar+

jacking stage

Figure 1: Photograph of the scattering chamber T1with the gas target mounted. The actual location of thegas cell, visible through the chamber window, is indi-cated.

a) North Carolina State University

17

18

Chapter 2

Experimental nuclear physics

19

2.1 Few-body physics activities at KVI; an overview

N. Kalantar-Nayestanaki, H. Amir-Ahmadi, J.C.S. Bacelar, A.M. van den Berg, A. Bieguna), K. Bodek b),R. Castelijns, M. Eslami-Kalantari, E. van Garderen, M.N. Harakeh, M. Kis, St. Kistrynb), A. Kozelac),H. Lohner, H. Mardanpour, A. Mehmandoostd), J.G. Messchendorp, A. Micherdzinskaa), M. Mahjour-Shafiei, S. Shende, E. Stephana), H. Wortche, J. Zejmab), W. Zippera)

Real and Virtual Bremsstrahlung andCapture Processes

The analysis of the real and virtual brems-strahlung experiments conducted in 2002 is fi-nalized. The experiment on real photon pro-duction aimed at measuring ppγ cross sectionsfor large proton opening angles, thereby ex-tending the earlier measurements performedwith the SALAD-TAPS combination. Someresults are presented in section 2.2. The analy-sis of the virtual bremsstrahlung has producedcross sections and response functions whichcan be compared to theoretical calculations(see section 2.3).

In 2003, a campaign of more than a monthwas conducted with the Plastic Ball and BBSto study the radiative (real and virtual) cap-ture process. In this process, large momen-tum components of the overlap integral as wellthe effects of two and three-body currents canbe investigated. For the real capture process,cross sections and analyzing powers were mea-sured as a function of beam energy (deuteronbeam energies of 110, 133 MeV and 180 MeV).For the virtual capture process (e−e+), a mea-surement was done for a month with the 180MeV deuteron beam. Final results of the an-alyzing powers of the real-photon productionare shown in section 2.4. First results of virtualphoton production are presented in section 2.5.

Spin Physics

The focus of this program is to investigatesimple reactions such as elastic and inelasticpd scattering in which the effect of the three-nucleon force are expected to be observed.

The break-up experiment with polarizeddeuterons on hydrogen target was completedin 2002 and the data are being analyzed. Thecross sections from the first campaign have

been published. First results of the analyzingpowers of the reaction are shown in section 2.6.

The first measurements of spin-transfer co-efficients in elastic proton-deuteron scatteringwith a polarized deuteron beam of 180 MeVtook place at the end of 2002 after a seriesof measurements for the calibration of the po-larimeter. The first results of cross sectionsand analyzing powers of this reaction are pre-sented in section 2.7. In order to derive thevalue of the beam polarization, it was neces-sary to perform calibration measurements atRIKEN, Japan. The preliminary results of theanalysis are presented in section 2.8.

The installation of the new detectionsystem, the Big Instrument for Nuclear-polarization Analysis (BINA), for the spin-physics program was completed in 2004 andthe first commissioning measurements werealso performed. Some results are presented insection 2.9.

Strangeness Production

The campaign with Crystal Barrel and TAPSat Bonn was successfully finished in 2003 andis now bearing results. The KVI group was in-volved in two of the measurements, namely thenucleon-resonance studies through the mea-surement of the K0Σ+ decay with proton anddeuteron targets. Some results from both tar-gets are presented in sections 2.10 and 2.11.

a) Institute of Physics, University of Silesia, Ka-towice, Poland.

b) Institute of Physics, Jagiellonian University,Cracow, Poland.

c) Institute of Nuclear Physics, Cracow, Poland.d) Also at Department of Physics, University of

Mashad, Mashad, Iran.

20

2.2 proton-proton bremsstrahlung towards the elastic limit

M. Mahjour-Shafiei, H.R. Amir-Ahmadi, J.C.S. Bacelar, R. Castelijns, K. Ermisch, E.Van Garderen,I. Gasparica), M.N. Harakeh, N. Kalantar-Nayestanaki, M. Kis, H. Lohner

The analysis of the pp-bremsstrahlung(hereafter ppγ) experiment towards the elas-tic limit was finished in 2004. This experimentwas a follow-up to the previous ppγ performedat KVI [1] to complete our knowledge on howthe level of agreement between the microscopicmodel of Martinus [2] and the experimentalcross section develops while moving towardsthe elastic limit, or equivalently low photon en-ergy in the center of mass (Ec.m.

γ ).

This experiment was set up using the back-ward hemisphere of the Plastic Ball detectorand SALAD to detect photons and protons,respectively. This version of Plastic Ball con-sists of 340 phoswich detector modules, cover-ing the polar angles between 90 to 160 withfull azimuthal coverage. SALAD consists ofa MWPC and two arrays of segmented plasticscintillators. The MWPC is employed to deter-mine the spatial coordinates of protons. Thefirst array of scintillators is used to measurethe energy of protons stemming from a brems-strahlung reaction, while the second array isused to distinguish between elastically and in-elastically scattered protons. In this measure-ment, SALAD detects particles in the polar-angle range of 10 to 28 with full azimuthalcoverage. With a more limited azimuthal-angle coverage, it can detect particles at polarangles of up to 36 effectively.

In this experiment, a total of 400 millionevents were collected of which 1.5% turned outto be good ppγ events. After eliminating thebackground, both cross sections and analyz-ing powers have been obtained and comparedwith the predictions of two different models.In Figure 1 the relative difference between thepredictions of a microscopic calculation [2] andexperimental cross sections have been plottedas a function of the relative energy of protons(Erel) or equivalently Ec.m.

γ . The relative en-ergy of protons is the invariant mass of protonsin the exit channel minus the rest mass of pro-tons. Erel or equivalently Ec.m.

γ is a measure of

how close the process is to the elastic limit.

[MeV]relE0 5 10 15 20 25 30 35 40 45

the

σ)/

exp

σ-th

eσ(

-0.2

0

0.2

0.4

0

5

10

15

[MeV]c.m.γE

5060708090

KVI 2002

Figure 1: The relative difference between the experi-mental and theoretical values of the ppγ cross sectionsas a function of Erel or equivalently Ec.m.

γ . The smoothcurve is fitted to the average of the relative difference.

As seen, the level of agreement between theprediction of the theory and the data does notimprove as one may have expected from theextrapolation of the previous data to high rel-ative energies [3]. Furthermore, at relative en-ergies around 33 MeV an abrupt decrease inthe relative difference is observed. The cause ofthis interesting behavior is not understood yet.Further investigations revealed that this be-havior occurs only for the cases where θ1 > θ2,with θ1 (θ2) being the polar angle of the pro-ton which is on the same (opposite) side as thephoton with respect to the beam direction. Itis expected that the predictions of the realis-tic models improve going towards the elasticlimit. Nevertheless, the question remains whythis holds only for the kinematics with θ1 > θ2,and not for θ1 < θ2. The statistical errors ofthe analyzing powers (not shown here) are toolarge to draw any strong conclusions. Never-theless, it seems that the analyzing-power dataare, as a whole, more in agreement with thepredictions of the microscopic calculations.

a) Institut Rugjer Boskovic, Zagreb, Croatia[1] H. Huisman, Ph.D. Thesis, RuG (1999).[2] G.H. Martinus, Ph.D. Thesis, RuG (1998).[3] M. Mahjour-Shafiei et al., Phys. Rev. C 70,

024004 (2004).

21

2.3 Electromagnetic response functions in pp scattering at 190 MeV

M. Kis, J.C.S. Bacelar, R. Caplar a), R. Castelijns, I. Gasparic a), M.N. Harakeh, N. Kalantar-Nayestanaki, H. Lohner, M. Mahjour-Shafiei, J.G. Messchendorp

The data analysis of the proton-proton vir-tual bremsstrahlung experiment is finished andthe final results are available. The goal of theexperiment was the study of the electromag-netic response functions (RF). These are nowextracted from the measured cross section andcompared to the theoretical predictions basedon the low-energy theorem (LET) [1].

Here we present the results of the extrac-tion of the interference response functions:WTT , W ′

TT , WLT , and W ′LT (Figure 1). In

order to extract the RFs, the cross section de-pendence on the so-called dilepton dihedral an-gle φl was used. Due to the fact that we per-form an integration over the acceptance of theexperimental setup, actually the averaged re-sponse functions W i are obtained. The datapoints are compared to the LET calculation(gray band). In order to illustrate the extrac-tion procedure and its quality, the contribu-tions (line with different shapes) of all RF tothe sum (gray band) are shown. Note that ineach panel only one contribution (given in boldline shape) is the principal, while all others areparasitic contributions.

For W TT we do not obtain a good extrac-tion due to the large parasitic contribution ofWT . However, the data are consistent with themodel prediction. Here the extraction is hin-dered by the acceptance of the experimentalsetup which can be cured by choosing a partic-ular part of the phase-space. Similarly, for theextraction of WLT we obtain that the WT par-asitic contribution dominates the result, butin this case our data indicate that the WLT

contribution is underestimated. A very goodextraction is obtained for W

′TT . In this case

all parasitic contributions are minimized andthe data are well described by the model pre-diction. For W

′LT we still have a reasonably

good extraction, especially if we bear in mindthat this RF has the weakest signal of all RFs.Here the parasitic contribution is of the sameorder as W ′

LT itself, and our data indicate that

W ′LT is underestimated by the model.

-0.05

-0.04

-0.03

-0.02

-0.01

0

WT

T [

fm6 ]

0

0.005

0.01

0.015

W / T

T [

fm6 ]

allW

T

WL

WTT

W’

TT

WLT

W’

LT

-0.06

-0.04

-0.02

0

0.02

WL

T [

fm6 ]

20 40 60 80Mγ [MeV]

-0.006

-0.004

-0.002

0

0.002

W / L

T [

fm6 ]

Figure 1: The extracted interference RFs plotted as afunction of the invariant mass Mγ of the virtual pho-ton. Each experimental data point is averaged overall events within the respective Mγ bin. The data arecompared to the LET calculation (gray band) where thethickness represents the statistical uncertainty of thecalculation. The other lines represent different contri-butions (see text) to the calculation and thus also to thedata.

a) Institute Rudjer Boskovic, Zagreb, Croatia.[1] A.Yu. Korchin, O. Scholten and D. van Neck,

Nucl. Phys. A 602, 423 (1996).

22

2.4 Vector and tensor-analyzing powers in p+d radiative capture

A.A. Mehmandoost-Khajeh-Dada), H. Amir-Ahmadi, J.C.S. Bacelar, A.M. van den Berg, R. Castelijns,E. van Garderen, M.N. Harakeh, N. Kalantar-Nayestanaki, M. Kisb, R. Koohi-Fayegh-Dehkordia,H. Lohner, M. Mahjour-Shafiei, H. Mardanpour, J.G. Messchendorp, B. Mukherjee, S.V. Shende,H.J. Wortche

The radiative proton-deuteron capture re-action p + d→3He+γ involves the lightest nu-cleus (3He) which allows to study the systemof three interacting nucleons. This channel isof particular interest since it provides valuableinformation on the high-momentum compo-nents of the <3He|pd> overlap wave function.The importance of studying the 3He system istherefore evident since it forms the bridge be-tween the well-understood two-body nucleon-nucleon case and heavier nuclei.

Recently, a precision deuteron-proton ra-diative capture experiment [1] at RCNPwas conducted using a vector and tensor-polarized deuteron beam impinging on a pro-ton target at an incident deuteron energy of100 MeV/nucleon. Interestingly, the prelimi-nary results on tensor-analyzing powers showlarge discrepancies with present-day calcula-tions. These deviations were found to be largerthan a factor of three for Axx in comparisonwith several different model approaches. Asa result, the authors speculated about possi-ble existence of new forces or new mechanismsthat are sensitive to tensor observables.

In September 2003, a radiative capture ex-periment was carried out at KVI with the aimto confirm the observed anomaly at RCNP andto extend the measurement at different ener-gies. In this experiment a coincidence setup ofthe Plastic Ball (PB) and the Big-Bite Spec-trometer (BBS) including the EuroSuperNovafocal-plane detection system was used to reg-ister the scattering angle of the photon andthe momentum of the 3He, respectively. Avector and tensor-polarized deuteron beam atenergies of 55, 66.5, and 90 MeV/nucleon im-pinged a liquid-hydrogen target placed at thecenter of the PB. The data have meanwhilebeen analyzed and vector and tensor-analyzingpowers have been obtained and submitted forpublication. Figure 1 shows the results of the

deuteron-proton radiative capture experimentin comparison with the calculation by the Han-nover theory group [2] based on the purely nu-cleonic CD-Bonn potential (dashed line) andits coupled-channel extension allowing for asingle excitation of a nucleon to a ∆ isobar(solid line). Meson-exchange currents (MEC)have been added in these calculations. Alter-native Faddeev calculations by the Bochum-Cracow theory group including explicit MECdo not differ much from those shown here. Ingeneral, our data do not show a large discrep-ancy with modern calculations and thereforedisagree with the anomaly observed at RCNP.

Figure 1: Polarization data for the deuteron-protonradiative capture reaction taken at KVI are comparedto predictions by a coupled-channel calculation of theHannover theory group.

a) Mashad Ferdowsi University, Physics depart-ment, Mashad, Iran.

b) Rudjer Boskovic Institute, Zagreb, Croatia.[1] K. Sagara et al., Proceedings of the Seventeenth

International IUPAP Conference on Few-Body Problems in Physics, Elsevier B.V.,S149 (2003).

[2] A. Deltuva et al., Phys. Rev. C 69, 034004(2004).

23

2.5 Virtual photon production in proton-deuteron capture reaction

E.D. van Garderen, H. Amir-Ahmadi, J.C.S. Bacelar, R. Castelijns, I. Gasparic a), N. Kalantar-Nayestanaki, M. Kis, H. Lohner, M. Mahjour-Shafiei, H. Mardanpur, A. Mehmandoost, J. Messchen-dorp, B. Mukherjee, S. Shende

The study of the response functions forthe radiative capture process of a proton bya deuteron has been performed in a pilot ex-periment done at the KVI using SALAD andTAPS [1]. To improve the accuracy of the re-sults, and to cover a larger angular region, wehave recently performed another experiment.

We used a 180 MeV deuteron beam anda liquid hydrogen target. The produced 3Hewere detected in the Big Bite Spectrometer(BBS) which was positioned at two differentangles: 3.5 and 1.7 in order to allow the cov-erage of the full 2-body kinematical locus. Thereal and virtual photons were detected in thePlastic Ball consisting of 575 ∆E-E scintilla-tors covering 60% of 4π. The trigger was de-rived from a coincidence of BBS scintillatorsand the Plastic Ball.

Preliminary results of the differential crosssection for real photons are shown in Figure 1(full triangles). For large angles (θCM > 50),our results are in good agreement with thepredictions from the coupled-channel potentialmodel of A. Deltuva [2] (line) and with the re-sults of Sagara et al. [3](circles, private com.)for similar studies of p + d → 3He + γ with adeuteron energy of 200 MeV. The theory over-predicts our data at small angles.

Figure 1: Differential cross sections for real photonsfrom p+d capture.

First results of the virtual photon (di-electron) production reaction have also beenobtained. Figure 2 shows the two leptonic an-gles θl and ϕl corresponding to the polar andthe azimuthal angles of the momentum-vectorl = 1/2(k+ − k−), where (k+, k−) are the 4-momenta of the positron and the electron, re-spectively. For definition of these angles, seeFigure 3 in ref. [1]. In the top panel, θl isminimum at 90, i.e. when both leptons carrythe same energy. θl increases as the differencebetween the two energies increases. The bot-tom panel shows the flat distribution of theazimuthal angle of l. The cross section andthe response functions for the virtual photonyield are presently under investigation.

Figure 2: The two leptonic angles θl and ϕl.

a)Institut Rudjer Boskovic, Zagreb, Croatia

[1] J.G. Messchendorp et al., Phys. Lett. B 481,171 (2000).

[2] A. Deltuva et al., PRC 67, 034001 (2003).[3] Sagara et al., private communication

24

2.6 First Results on Analyzing Powers of the 1H(d, pp)n BreakupReaction at 130 MeV

A. Bieguna), K. Bodek b), N. Kalantar-Nayestanaki, M. Kis, St. Kistrynb), B. Klosa), A. Kozelac),M. Mahjour-Shafiei, A. Micherdzinskaa), E. Stephana), R. Sworstb), J. Zejmab), W. Zippera)

Theoretical studies of deuteron-protonbreakup predict large contributions of the gen-uine 3N interaction (3NF) for vector and ten-sor analyzing powers in numerous regions ofthe phase space. These effects vary stronglywith the choice of a particular combination ofthe NN interaction with the 3NF model [1].

About 20% of the breakup data have beenanalyzed in order to extract analyzing powers.Elastic scattering events were used for deter-mining the vector and tensor polarization ofthe deuteron beam. For a given polar angleθp of the outgoing proton, the rate of proton-deuteron coincidences was analyzed as a func-tion of the azimuthal proton angle ϕ. Fromthe obtained rates, Np for a given polarizationstate and No for polarization equal to 0 (bothnormalized to the collected charge), the ratiof = (Np − No)/No was constructed. The am-plitude of its oscillations is a measure of thebeam polarization. Examples of such experi-mental dependencies of the ratio f are shownin Figure 1.

Figure 1: Ratio f for p-d coincidences as a functionof the azimuthal proton angle for θp = 17o ± 0.5o anddifferent polarization states.

In absence of the experimental data weuse theoretically calculated analyzing powersof the dp elastic scattering. Values of polar-ization obtained then from the fit of the os-cillation curves vary between 46% and 56% ofthe nominal values (listed in Fig. 1), for bothvector and tensor polarizations.

Using the extracted polarization values,analyzing powers for the breakup process wereobtained. Breakup events belonging to a given

configuration were sorted with respect to theS value and to the azimuthal angle ϕ of thefirst proton. From the normalized rates theratio f , in full analogy to the elastic scatteringcase, was constructed. For each bin along Sthe dependence f(ϕ) was fitted with the an-alyzing power values as parameters. Exam-ples of comparison of tensor analyzing powerswith the theoretical predictions are shown inFig. 2. The light-grey bands show the predic-tions obtained with the use of NN potentials(CD-Bonn, AV18, Nijm I and II) only, whilethe dark-grey ones represent predictions whenthe TM99 3NF model is included into the cal-culations.

40 60 80 100 120 140 160 180S (MeV)

-0.2

0

0.3

T22

-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

0.25

40 60 80 100 120 140 160 180S (MeV)

-0.2

-0.1

0

0.1

0.2T20θ1 = 20° ± 1°

θ2 = 20° ± 1°ϕ12 = 120° ± 5°

θ1 = 15° ± 1°θ2 = 15° ± 1°ϕ12 = 90° ± 5°

Figure 2: Tensor analyzing powers of the breakup re-action for two selected kinematical configurations. The-oretical predictions are shown as bands - see text. Theerror bars represent statistical uncertainties togetherwith the polarization determination errors.

At the present stage of analysis of the an-alyzing powers no clear statement on the pre-ferred dynamics can be made, unlike the caseof the cross-section data [2]. Quantitative con-clusions are expected when the full accumu-lated statistics are taken into account.

a) Institute of Physics, University of Silesia, Ka-towice, Poland.

b) Institute of Physics, Jagiellonian University,Cracow, Poland.

c) Institute of Nuclear Physics, Cracow, Poland.[1] J. Kuros-Zolnierczuk et al., Phys. Rev. C 66,

024003 and 024004 (2002).[2] St. Kistryn et al., Phys. Rev. C 68, 054004

(2003).

25

2.7 The analysis of elastic H(d, p) reaction at 90 MeV/nucleon

H.R. Amir-Ahmadi, A. van den Berg, R. Castelijnes, E.D. van Garderen, N. Kalantar-Nayestanaki,M. Kis, H. Lohner, M. Mahjour-Shafiei, S.V. Shende, J.G. Messchendorp and H.J. Wortche

While the Nucleon-Nucleon (NN) reactionhas received much interests, there are not asmany experiments involving three nucleons.The Three-Nucleon Force (3NF) is still notwell established and there are big differencesbetween the predictions of different models of3NF. To understand the effects of three bodyforces and achieve a realistic potential moreexperiments must be performed. The three-nucleon system has been studied systemati-cally at KVI. After measuring the cross sectionand analyzing power of the reaction 2H(p, pd)for several energies by Karsten Ermisch, ex-periment F11 aims to measure the cross sec-tion, analyzing powers and in particular polar-ization transfer coefficients of the H(d, p) re-action at 90 MeV/nucleon. These observableshave been calculated theoretically using twoand three body potentials and the results canbe compared with the experiment results.

To measure the polarization of the protonsemerging from the reaction by the polarimeterof the BBS, a calibration experiment of H(p, p)was performed. In that experiment, the ana-lyzing power of p-C for the energy range of(60-160 MeV) was measured and the resultsfor above 100 MeV are compared with the pub-lished data of other laboratories. Preliminaryresults of this experiment are reported in [1].

The cross section of H(d, p) reaction isI = I0(1 + 3

2pyAy + 23pxzAxz

+13

(pxxAxx + pyyAyy + pzzAzz)) (1)

where I0 is the unpolarized cross section, Ay

is the vector analyzing power and Aij are thetensor analyzing powers. py and pij are vectorand tensor polarizations of the incident beam,respectively. Figure 1 shows the unpolarizedcross section and Figure 2 shows the vector andtensor analyzing powers measured at KVI incomparison with theoretical predictions. Theanalyzing powers are extracted using various

states of polarization. The results are still pre-liminary.

Figure 1: Unpolarized differential cross section of theH(d, p) reaction as a function of c.m. angles.

At KVI we could measure Ay and Ayy

because polarized deuteron beam with onlyy-component, py and pyy, are accessible atpresent. Work on extracting the polarization-transfer coefficients is in progress.

Figure 2: The vector and tensor analyzing powersmeasured at KVI in comparison with the theoretical cal-culations.

[1] H.R. Amir-Ahmadi et al., KVI annual report,32 (2003)

26

2.8 Determination of vector and tensor-analysing powers in elasticdeuteron-proton scattering

H. Mardanpour, H.R. Amir-Ahmadi, N. Kalantar-Nayestanaki, T. Kawabataa), H. Kuboki b), Y. Maedaa),J.G. Messchendorp, S. Sakaguchia), H. Sakaia,b) , N. Sakamotoa), Y. Sasamotoa), K. Sekiguchia),K. Sudaa), Y. Takahashi b) , T. Uesakaa) and K. Yakob)

The measurement of the analysing powersof deuteron-proton elastic scattering at inci-dent deuteron energies of 130 and 180 MeV wascarried out at RARF in May 2004. The exper-iment was composed of two parts. For the firstpart, asymmetries in proton-deuteron elasticscattering were obtained using the in-beampolarimeter. Simultaneously, using the samebeam, the polarization was measured via theC(d, α)B(2+) reaction using the SMART spec-trograph. The analysing powers were conse-quently derived by combining the results of thebeam polarization with the asymmetry mea-surement of the polarimeter. The analysingpowers were measured for 6 different angles inthe center-of-mass reference frame.

The beam polarization can be obtained un-ambiguously since the analysing powers of theB(2+) state of C(d, α)B(2+) are known exactlyat zero degrees to be T20(θ = 0) = 1√

2. Figure

1 shows the measured excitation energy spec-trum of the C(d, α) reaction. The B(2+) statecan be clearly identified.

The D-room polarimeter is composed of 24different proton counters and 4 deuteron coun-ters, placed left, right, up and down arounda CH2 target. For each proton detector, thecorresponding deuteron counter is located onthe other side of the beam. Thus the setupmakes it possible to measure the asymmetriesat 6 different angles via a coincidence setup.The deuteron beam interacts with a CH2 tar-get placed at the center of the polarimeter.

By measuring the asymmetries in the hor-izontal and vertical planes in the D-room po-larimeter and using the obtained polarizationvalues from SMART, the analysing powers ofthe d-p reaction can be obtained experimen-tally. Some preliminary analysing powers ofthe elastic deuteron-proton reaction at 180MeV are shown in Figure 2. The preliminarydata are compared to Faddeev calculations by

Bochum-Cracow theory group [1].

Figure 1: Excitation energy spectrum of 10B.

Figure 2: Preliminary analysing powers for 180 MeV.The errors are dominated by a 5% systematic uncer-tainty.

a) Center for Nuclear Study, University of Tokyo,Japan.

b) Department of Physics, University of Tokyo,Japan.

[1] H. Witala et al., Phys. Rev. C 63, 024007(2001).

27

2.9 Status of BINA

H. Mardanpour, H.R. Amir-Ahmadi, M. Eslami-Kalantari, N. Kalantar-Nayestanaki, M. Kis, M. Mahjour-Shafiei, J.G. Messchendorp, F. Mula), A. Kozelab)

In the last few years, high-precision mea-surements of the elastic p + d reaction werecarried out at KVI with the aim of studyingthree-nucleon forces (3NF). In the near future,a second generation of 3NF studies will be con-ducted using the new detector system calledBINA. This detector is particularly suited tostudy the p + d break-up reaction. BINA iscomposed of two major parts: the forward wallwhich measures the energy, the position andthe polarization of hadrons at scattering an-gles in the range 10-35, and the backwardball part which covers the rest of the polar an-gle up to 165. The two parts together, there-fore, cover almost the entire kinematic phasespace of the break-up reaction. Figure 1 showsa side view of BINA.

Figure 1: Side view of BINA. The backward ball andforward wall can be observed on the left and right handside of the picture, respectively. ∆E detectors andMWPC are not shown here.

The installation of BINA was completed atthe end of spring 2004. The main parts of de-tector including the backward ball, a MWPC,the forward wall ∆E detectors and the data ac-quisition system were all installed successfullyin 2004.

The first commissioning of BINA was con-ducted in June 2004. The response of the scin-tillators and MWPC was examined using a 190MeV proton beam on a CD2 target.

In the second commissioning which wasperformed in November 2004, one of the pas-sive splitters was replaced by an active splitter

to improve the dynamic range of the ADCs byoptimizing the signal size. Furthermore, thecryogenic LD2/LH2 target was installed andtested successfully.

E (channel no.)0 200 400 600 800 1000 1200 1400

dE

(ch

ann

el n

o.)

0

200

400

600

800

1000

1200

1400

Figure 2: Energy histogram of particles in the forwardwall.

The combination of energy (E ) responseof horizontal scintillator bars and vertical ∆Escintillators in the forward wall is used to dis-criminate protons from deuterons. Figure 2shows a (∆E, E) response of the forward wall.

The MWPC is used to determine the scat-tering angle of the final-state protons anddeuterons. Figure 3 presents (x , y) planes ofMWPC in a measurement of particles from theelastic p + d reaction.

X (Wire no.)0 20 40 60 80 100 120 140 160 180

Y (

Wir

e n

o.)

0

20

40

60

80

100

120

140

160

180

Figure 3: The response of the MWPC.

a) Faculty of Exact Science, Free University ofAmsterdam, Amsterdam.

b) Institute of Nuclear Physics, Cracow, Poland

28

2.10 Nucleon-resonance decay through the K0Σ+ channel

R. Castelijns, J.C.S. Bacelar, H. Lohner, J. Messchendorp, S. Shendefor the CB-ELSA/TAPS collaboration

In order to test quark models, accuratedata are required in many different excitationchannels. We have conducted an experimentduring 2002 and 2003 to measure the photo-production cross section of K0Σ+ on the pro-ton. These experiments have been carried outat the tagged photon facility of the ELSA elec-tron accelerator in Bonn, using a combinationof the Crystal Barrel and TAPS spectrometers.ELSA delivered an electron beam of 3.2 GeV,resulting in a tagged photon energy range of0.7 to 3.0 GeV.

Data were taken with polarized and unpo-larized photon beams on both liquid hydrogenand liquid deuterium targets, but only resultsof unpolarized hydrogen measurements are dis-cussed here. Our analysis of these data iden-tifies the channel of interest by selecting thedecay:

γp → K0Σ+ → π0π0π0p → 6γp

In order to achieve this, all events contain-ing seven hits were kinematically fitted, vary-ing all measured energy and momentum values(except the proton energy) within the detectorresolutions. The three pion masses and con-servation of momentum and energy were usedas constraints.

Because of the strange quark content of theΣ+, this state is forced to decay weakly andtherefore has a long lifetime. This means itsdegree of polarisation after the reaction (recoilpolarisation) can be measured. This is doneby counting the number of Sigma’s which de-cay with a proton above and below the planedefined by the initial reaction. The polarisa-tion is the defined by

P = 2α

Nup−Ndown

Nup+Ndown

Where α is a measure of the parity break-ing in the decay Σ → pπ0 and is known veryprecisely. Figure 1 shows our results for therecoil polarisation compared to an older mea-surement [1].

)cm0K

θcos( -1 -0.5 0 0.5 1

P

-1.5

-1

-0.5

0

0.5

1

1.5

CB/TAPS preliminary dataSaphir data (R. Lawall et al.)

Figure 1: Recoil polarisation compared to SAPHIRresults[1].

In order to extract cross sections, the dataneed to be normalised. This is done by usingone of the other channels selected by the kine-matic fit:

γp → ηp → π0π0π0p → 6γpThis channel has been studied in great de-

tail before [2], and can therefore be used forthe absolute normalization of the channel ofinterest. Figure 2 shows our results for theη differential cross section normalised to thedata from [2], for a typical incident photon en-ergy bin. The normalisation factor obtainedfrom this can now be used to determine the to-tal and differential cross sections for the K0Σ+

channel (work in progress).

)cmηθcos(

-1 -0.5 0 0.5 1

Arb

. un

its

0

200

400

600

800

1000

CB/TAPS preliminary dataCrystal Barrel data (V. Crede et al.)

Figure 2: Differential η cross section normalized toCrystal Barrel data[2].

[1] R. Lawall, PhD thesis, Bonn (2004).[2] V. Crede et al., Phys. Rev. Lett. 94, 012004

(2005).

29

2.11 Nucleon-resonance studies on the deuteron

S. Shende, R. Castelijns, J.C.S. Bacelar, H. Lohner, J. MesschendorpFor the CB-ELSA/TAPS collaboration

The production of a strange meson (K0)from the deuteron along with a hyperon (Σ+)may provide information on the hyperon-neutron interaction. Scarce experimental dataare available from hyperon scattering, chargeexchange and inelastic processes. Till now nodata are available in the Σ+n channel. A cal-culation [1] including the final-state interactionpredicts a significant enhancement of the crosssection at the Σ-nucleon threshold in compari-sion to the plane-wave approximation, see Fig-ure 1.

Figure 1: Differential cross section for K productionas a function of the photon energy [1].

During 2003 the experiment γd→K0Σ+nhas been erformed with the tagged photonbeam from the ELSA synchrotron facility atBonn using photon beams up to 3 GeV ona liquid deuterium target. The hyperon- andmeson-decay photons have been measured bythe Crystal-Barrel (CB) in combination withthe TAPS spectrometer at forward angles,both covering almost 95% of 4π. Charged par-ticles were detected by three layers of scintil-lating fibers in the inner detector surround-ing the liquid hydrogen (deuterium) target.The forward going charged particles were sig-nalled by plastic scintillators from the VETOdetector in front of TAPS. Before and afterthe data-taking runs the signals from cosmicmuons were measured providing a relative cal-ibration. The energy calibration was achievedby reconstructing separately the 2γ invariant

mass from TAPS and from CB and adjustingthe detector gains in an iterative procedure.A pion mass resolution (σ) of 9 MeV has beenachieved. For the time calibration, two-photonhits in TAPS alone were reconstructed result-ing in a resolution (FWHM) of 0.8 ns.

As a first step of the data analysis, thechannel γd→ηpn→π0π0π0pn→6γpn has beeninvestigated. Here, the neutron is assumed toact as spectator and only seven-cluster eventshave been selected. In a kinematical-fittingprocedure the energies and momenta of de-tected photons and the proton were allowedto vary within the detector resolution. Thepion mass, total energy and the momentumbalance were used to constrain the kinematicequations. The resulting 3π0 invariant mass isplotted in Figure 2. A mass resolution (σ) of10 MeV has been achieved.

(MeV)0π 0π 0πM

300 400 500 600 700 800 900 1000

cou

nts

1

10

102

103

kinfit Eta CL cut > 0.1

Figure 2: The 3π0 invariant mass for γd→ηpn→π0π0π0pn→6γpn channel.

In a refined analysis we will improve thecharged-particle efficiency by closer inspectionof different layers of the Inner Detector andneighbouring hits in the VETO detector alongwith timing information in TAPS. Preliminaryyields of K0 and Σ+ have been obtained. In or-der to study the final state interaction, the ki-netic energy of the neutron will be determinedfrom a missing energy analysis.

[1] B.O.Kerbikov, Phys. Atom. Nuclei 64, 1835-1840 (2001).

30

2.12 Radiation damage in large-area avalanche photodiodes

H. Lohner, P. Dendooven, T. Held b), H. Kiewiet, B. Lewandowski b), P. van Luijk d), R. Novotny a),H. Nowak b), K. Peters b), M. Steinke b), U. Wiedner c), Peter Wieczorek b), A. Wilms b)

Within the EC project I3-HadronPhysicswe have continued efforts for electromagneticcalorimeter development [1]. For applica-tions in strong magnetic fields (e.g. 1.5 T atthe PANDA EM calorimeter) silicon avalanchephotodiodes (APD’s) are advantageous be-cause of their insensitivity to magnetic fieldsand little response to ionizing radiation. Forthe combination with lead tungstate (PWO)crystals the CMS collaboration applies 5x5mm2 APD’s from Hamamatsu Photonics.A new development of Large Area APD’s(LAAPD of 10x10 mm2) suited for the rearend of PANDA PWO crystals was necessary.Here we report on tests of radiation damage in-duced by protons leading to increased surfacedark current or increased bulk dark current.A first prototype was tested at PSI with 70MeV protons. It turned out that the dark cur-rent after a fluence of 5·102 p/cm2 was alreadytwice as high as measured for the CMS APDat twice the fluence. An improved prototypecontained a groove in the surface structure inorder to reduce the surface current. These pro-totypes were tested at KVI with 90 MeV pro-tons and compared to the CMS APD. The ir-radiation was performed at the multi-user ir-radiation facility mainly used for radiobiologyexperiments. The applied proton fluence wasdetermined with an accuracy of about one per-cent.

Figure 1: Leakage current as function of irradiationtime for standard CMS APD.

The homogeneity of the irradiation acrossthe APD surface was better than 5%. Testswere carried out at room temperature and -

25oC at beam currents of 0.4 and 4 nA. Figure1 shows the leakage current as function of irra-diation time for a standard CMS APD at roomtemperature. The irradiation was started witha beam current of 0.4 nA until a fluence of1012 p/cm2 was reached. The leakage currentincreases with a slope of 0.6 nA/s. Thereafterthe irradiation was continued with additional1013 p/cm2. The leakage current slope is now5.4 nA/s and thus about 10 times larger. Amaximum current of 27 µA is reached. Clearlyvisible is the decrease of leakage current due toannealing in the short beam-off periods.

Figure 2: Leakage current as function of irradiationtime for Large Area APD.

Figure 2 shows the result for an LAAPD ir-radiated under the same conditions. The slopeof the leakage current changes from 3.2 nA/sto 9.3 nA/s when increasing the beam currentfrom 0.4 to 4 nA, while a maximum leakagecurrent of 55 µA is reached. These valuesare worse than those for the small CMS APDbut indicate an acceptable radiation tolerance.The irradiation at -25oC with a beam currentof 4 nA revealed a moderate leakage current in-crease of 2.9 nA/s. This indicates a reasonableradiation tolerance with rapid decrease of leak-age current in the beam-off periods. Improvedprototypes and the yield of radiation-hard sen-sors will be tested in a subsequent beam periodunder the same conditions.

a) II. Physik. Institut, University Giessenb) Experimentalphysik I, University Bochumc) Physics Institute, University Uppsalad) UMC Groningen[1] KVI Annual Report, 35 (2003).

31

2.13 Measurements of the 28Si(p,t)26Si reaction to determine ratesin the stellar rp-process

A. Matic, T. Adachia), G.P.A. Berg, A.M. van den Berg, H. Fujitab), K. Fujitac), Y. Fujitaa), J.Gorresd), K. Hatanakac), P. Leblancd), Y. Sakemi c), H. Schatz e), Y. Shimbaraa), Y. Shimizuc), Y.Tameshigec), A. Tamii c), T. Wakasaf), M. Wiescherd), H.J. Wortche, M. Yosoi c)

The reaction rate for the production of26Alg.s is one of most interesting open ques-tions in nuclear astrophysics. The 26Alg.s. hasa half-life of 7.2 × 105 yr; it decays via β+ tothe first-excited state of 26Mg, followed by theemission of a prompt 1.809 MeV γ-ray. Suchγ-rays have been observed by the telescopesCOMPTEL and CGRO. These obervations area very valuable method to check models de-scribing explosive hydrogen burning processesin novae.

region of interest

6.30

0

6.38

0

O14

O14

14O

10C 7.90

0

7.42

5

5.14

5 O14

Energy [ MeV ]

0111098765

Si(p,t)28 26

Si

cou

nts

/2.5

keV

300

250

200

150

100

50

Ep=100 MeVθ t=−0.3

o

Figure 1: Excitation-energy spectrum of 26Si obtainedthrough a measurement of the 28Si(p,t)26Si reaction.

The production of 26Alg.s. proceeds via thereaction:25Al(β+ν)25Mg(p,γ)26Alg.s.(β+ν)26Mg∗(γ).However, the production of 26Alg.s. can bebypassed via:25Al(p,γ)26Si(β+ν)26Alm(β+ν)26Mgg.s..This last reaction yields the largest uncertaintyin calculations of reaction rates for the pro-duction of 26Alg.s.. This uncertainty is due tothe lack of nuclear-structure information justabove the proton threshold in 26Si (Sp=5.518

MeV). The energy resolution of relevant lev-els obtained in previous studies was 75 keV,so closely spaced states may not have beenresolved.

We performed a 28Si(p,t)26Si experiment toobtain high-resolution excitation-energy spec-tra for the region above the proton and α-threshold. This experiment was performed atRCNP Osaka using a proton beam at Ep =100 MeV extracted from the RING cyclotron.Self-supporting targets of 26Si with a thick-ness of 700 µg/cm2 and, for identification ofimpurities, targets of mylar (1 mg/cm2), andpolyethylene (1 mg/cm2) were used. The dis-persive WS beam line and the Grand Raidenspectrometer with its standard focal-plane de-tector system in over focus mode were used tomeasure the position and angles of the outgo-ing tritons in the focal plane. We obtain anenergy resolution with an unprecedented valueof 15 keV (fwhm).

In Figure 1, the excitation-energy spectrumof 28Si(p,t)26Si is shown in the region above theproton threshold (Sp=5.518 MeV) and identi-fied states of 26Si are indicated. The obtaineddata will be used in network calculations tocalculate reaction rates for the 25Al(p,γ)26Sireaction.

a) Department of Physics, Osaka University, Os-aka, Japan.

b) WITS, University of South Africa.c) Research Center for Nuclear Physics, Osaka,

Japan.d) Department of Physics, University of Notre

Dame, South Bend IN, USA.e) Department of Physics, Michigan State Univer-

sity, East-Lansing MI, USA.f) Department of Physics, Kyushu University,

Fukuoka, Japan.

32

Chapter 3

Theory

33

3.1 Covariant Rarita-Schwinger propagator in the nuclear medium

A. E. L. Dieperink, C. L. Korpa a)

The spin-3/2 isospin-3/2 ∆(1232) baryoncouples strongly to the nucleon and pion andplays an important role in nuclear processeswith excitation energy of a few hundred MeV.This raises the issue of the propagation of aspin-3/2 particle in the nuclear medium. Thespin-3/2 particle is usually described by us-ing the Rarita-Schwinger field, which consistsof four, Lorentz-vector indexed, Dirac spinors.A free theory can be formulated in which thenumber of degrees of freedom is as a conse-quence of the equations of motion reduced tothe required 8 (for a complex field). However,for realistic description of spin-3/2 resonancesone needs to introduce interactions taking intoaccount their decay channels.

Introducing interactions of general forminto the above free-field theory introducesalso spin-1/2 components into the propagator.This type of approach was used quite exten-sively in the past and was phenomenologicallysuccessful. Recently, it has been argued [1]that an interaction vertex which preserves thecorrect number of degrees of freedom for thespin-3/2 particle should be used, and it hasbeen shown that the two types of couplingscan be transformed into each other by a re-definition of the field describing the spin-3/2particle, at the expense of new contact inter-actions appearing (not containing the spin-3/2field) in the Lagrangian. These contact inter-actions may be associated with other spin-1/2fields in the theory.

The propagator is defined by

Gµν(p) = i

∫d4xeip·x 〈0|T Ψµ(x)Ψν(0)|0〉,

where Ψµ is the Rarita-Schwinger field and|0〉 can denote either the vacuum or the nu-clear medium. In vacuum this propagator (orthe self energy, which is given by the am-putated diagrams can be expanded in termsof 10 Lorentz-scalar functions of p2. In thenuclear medium, however, the propagator ac-quires more independent components than in

vacuum, since the presence of the (rotation-ally symmetric) medium means that preserv-ing the Lorentz-covariant description requiresintroducing another four-vector, namely themedium’s four velocity. This quadruples thenumber of terms the propagator can be ex-panded in.

Energy [GeV]

1.0 1.1 1.2 1.3 1.4 1.5 1.6

Spe

ctra

l fun

ctio

n [1

/GeV

]

0

2

4

6

8

10

Helicity-1/2

Helicity-3/2p = 0

p = 600 MeV

p = 300 MeV

Figure 1: The isobar spectral function in the medium.

In Ref. [2] we provided a general schemefor a fully Lorentz-covariant treatment of thespin-3/2 particle’s in-medium propagation, an-alytically separating all its components. Thismeans introducing a convenient basis for theexpansion of the self energy and the prop-agator, which makes subsequent calculationspractical for arbitrary vertices involving theRarita-Schwinger field. Using our formalismthe full relativistically covariant contributionof the pion-nucleon loop to the isobar selfenergy and propagator in isospin-symmetricspin-saturated nuclear medium was computed.Utilizing this propagator the photoabsorptioncross section on in-medium nucleons in the iso-bar region was calculated and the result wascompared with experimental data.

a) University of Pecs, Hungary.[1] V. Pascalutsa, Phys. Rev. D 58, 096002

(1998); V. Pascalutsa and R. Timmermans,Phys. Rev. C 60, 042201 (1999).

[2] C. L. Korpa and A. E. L. Dieperink, Phys.Rev. C 70, 015207 (2004).

34

3.2 The nucleon-sigma coupling constant in external-field QCD SumRules

G. Erkol, Th. A. Rijken a), R. G. E. Timmermans

Determining the meson-baryon couplingsis of particular interest in understanding thenucleon-nucleon (NN) and hyperon-nucleon(YN) interactions in terms of one-boson ex-change (OBE) models. The scalar mesonsconstitute a significant role in construction ofsuch phenomenological potential models. Theσ meson, which was introduced in the early1960’s, is necessary for providing sufficientintermediate-range central attraction and forthe spin-orbit interaction required to describethe splitting of the NN 3PJ phase shifts. Whilethe status of the scalar mesons in QCD re-mains controversial, the σ (or “ε”) meson isbest viewed as a chiral partner of the pion, andis most likely the isosinglet member of a nonetof low-lying scalar mesons, possibly cryptoex-otic four-quark states [1].

We have studied the nucleon-σ meson cou-pling constant gNNσ using the QCD Sum Rules(QCDSR) method [1]. QCDSR is a challeng-ing approach that links the hadronic degreesof freedom with the underlying QCD parame-ters, and serves as a very useful tool to extractqualitative and quantitative information abouthadron properties.

We have calculated gNNσ using theexternal-field QCDSR method. We evaluatethe vacuum to vacuum transition matrix ele-ment of two nucleon interpolating fields in anexternal scalar-isoscalar σ field. On the theo-retical side, the correlation function is calcu-lated using the Operator Product Expansion(OPE) in the Euclidian region. This correla-tion function is then matched with an ansatzwhich is introduced from the hadronic degreesof freedom on the phenomenological side. Inparticular, we construct two sum rules one ofwhich leads to a stable result with respect to

change in Borel mass. We also compute thecontributions that come from the excited nu-cleon states and the response of the continuumthreshold to the external field.

In order to evaluate gNNσ we need to knowthe values of the scalar susceptibilities χ andχG which correspond to the response of thequark and quark-gluon mixed condensates tothe external field, respectively. We estimatethe values of χ and χG using a recent analysisof π-π scattering with chiral perturbation the-ory [3]. We also need the value of the quark-σcoupling constant gσ

q as input, which we esti-mate from the σ-model. Our final result forgNNσ is

gNNσ = 14.4 ± 3.7 . (1)

This coupling constant is defined at t = 0. Alsoin NN fits the scalar coupling constants are de-termined at t = 0. The value of gNNσ obtainedin Eq. (1) is in agreement with the one from theNijmegen soft-core potential model [4], whichis given as: gNNσ = 16.9.

We have also extended the calculations ofexternal-field QCDSR to the hyperons and theother scalar nonet members in order to providethe complete SU(3)-flavor structure of scalarmeson-baryon couplings.

a) University of Nijmegen, the Netherlands.[1] R. G. E. Timmermans, Th. A. Rijken and J.

J. de Swart, Phys. Rev. C 50, 48 (1994).[2] M. A. Shifman, A. I. Vainshtein and V. I. Za-

kharov, Nucl. Phys. B 147, 385 (1979);Nucl. Phys. B 147, 448 (1979).

[3] G. Colangelo, J. Gasser and H. Leutwyler,Nucl. Phys. B 603, 125 (2001).

[4] M. M. Nagels, Th. A. Rijken and J. J. de Swart,Phys. Rev. D 17, 768 (1978).

35

3.3 P- and T-odd two-nucleon interaction and the deuteron electricdipole moment

C.-P. Liu, R. G. E. Timmermans

In the field of particle physics an atomicphysics quantity plays a privileged role: theelectric dipole moment (EDM), which violatesparity (P ) conservation and time reversal (T ,or equivalently CP ) invariance. The StandardModel predicts EDMs that are much too smallto be detected in the foreseeable future, andhence a nonzero EDM is an unambiguous sig-nal of a new source of CP violation. Recently,a new highly-sensitive method has been pro-posed to directly measure the EDMs of chargedparticles in a magnetic storage ring [1]. Anexperiment has been proposed to measure theEDM of the deuteron at the 10−27 e–cm level(see contribution 1.6). From a theoreticalpoint of view, the deuteron is especially attrac-tive, because it is the simplest system in whichthe P -odd, T -odd nucleon-nucleon (NN) inter-action contributes to the EDM. Moreover, thedeuteron properties are well known, so preciseand reliable calculations are possible.

We have addressed the EDM of thedeuteron (dD) in Ref. [2], and compared theresult to the EDM of the neutron (and pro-ton), all evaluated with the most general struc-ture of the P - and T -odd NN interaction. Thedeuteron EDM is the sum of one- and two-body contributions, dD = d

(1)D + d

(2)D . The to-

tal one-body contribution is simply the sumof the proton and neutron EDMs, i.e. d

(1)D =

dp + dn; the dominant contribution to the nu-cleon EDM involves the well-known (isovector)chiral logarithm. For the two-body part, thedominant contribution comes from the polar-ization effect: In leading order in the pertur-bation, it is the matrix element of the chargedipole operator evaluated between the unper-turbed deuteron state |D〉 (mainly 3S1-wavewith some 6% 3D1-wave) and the admixed 3P1-wave component |D〉, viz.

d(pol)D =

√16〈D||τ z

− er ||D〉 , (1)

where r = r1 − r2. The model dependenceof the matrix element was shown to be mini-

mal by using different high-quality NN poten-tial models. Meson-exchange effects give onlya few-% correction compared to d

(pol)D .

Our final result for the deuteron EDM,written in terms of the P - and T -odd meson-nucleon coupling constants, reads [2]

dD = 0.23 g(1)π + 0.09 g(0)

π

+0.04 g(1)ρ + 0.01 g(0)

ω . (2)

The deuteron and neutron results illustratehow limits on their EDMs could be used toprovide tight constraints on a specific modelof CP violation. For supersymmetric models inwhich the Pecci-Quinn symmetry is evoked toremove the QCD θ term, the quark color EDMsare the dominant contributors to the CP -oddmeson-nucleon coupling constants, comparedto the three-gluon and four-quark operators[3]. Therefore, all the g’s can be expressed interms of the dc

q’s, and the deuteron and neu-tron EDMs can be written in terms of the colorEDMs of the up and down quarks as

dD = −4.67 dcd + 5.22 dc

u , (3)dn = −0.01 dc

d + 0.49 dcu . (4)

Thus, these two EDM measurements probe dif-ferent linear combinations of dc

d and dcu in this

case. Moreover, the deuteron could be signif-icantly more sensitive than the neutron. Ingeneral, one expects that, barring unnaturalcancellations, the deuteron is competitive tothe neutron in sensitivity to CP violation. Fur-thermore, the deuteron EDM involves differentcoupling constants, and hence in general willbe complementary with respect to the informa-tion about CP violation that can be obtained.

[1] F. J. M. Farley et al., Phys. Rev. Lett. 93,052001 (2004).

[2] C.-P. Liu and R. G. E. Timmermans, Phys.Rev. C 70, 055501 (2004).

[3] M. Pospelov, Phys. Lett. B 530, 123 (2002).

36

3.4 The Dibaryon resonance and two-photon bremsstrahlung

Ojwang, J.G.O., and O. Scholten

There are longstanding claims about theexistence of a di-baryon resonance (d∗). Sincesuch a state should not couple directly to atwo nucleon scattering state, the process ofproton-proton scattering under the emission oftwo photons, i.e. in the process pp → Dγ →2γNN , is the most promising method to seethe signals of such a d∗ state. To investi-gate the effect of a possible dibaryon reso-nance on the cross section of the pp → ppγγwe have added coherently the amplitude fortwo-photon bremsstrahlung to that for thedibaryon process. A model for the brems-strahlung process, which obeys the low-energyconstraints, has been proposed in [1]. Thedibaryon contribution is included assuming itto be a(JP , T ) = (0±, 2) state with mass MD =1956 MeV.

20 40 60 800

10

20

30

(nb/

sr2

GeV

2ra

d2 ) 2=1201=80

m =50 MeV=200 0+

20 40 60 800

10

20

30

D

tot0-

E (c.m.) [MeV]

Figure 1: The fully exclusive cross sectiond8σ

dΩ1dΩ2dθγγdMγγdφ1dε1as a function of photon energy

for two different co-planar kinematics. The brems-strahlung contribution is given by the dotted curve, thedibaryon contribution is given by the dashed curve whilethe total cross section is given by the drawn curve. Theleft (right) panels show the results for a Jπ = 0− (0+)dibaryon respectively.

Figure 1 shows the calculated fully exclu-sive cross section, assuming positive and pari-ties for the dibarion. Strong interference is ob-served where the pattern clearly distinguishes

the quantum numbers of the state.

20 40 60 800.0

0.5

1.0

1.5

Px=

x/to

t

m =50 MeV=200

2=1201=800+

20 40 60 800.0

0.5

1.0

1.5

PD

P0 -

E [MeV]

Figure 2: The cross section rations, defined in Eq. (1)and Eq. (2) plotted as function of photon energy. Dot-ted line shows the resonance contribution, dashed lineshows the bremsstrahlung contribution and the drawncurve the quantity P .

It should be noted that the cross sectiondue to the dibaryon mechanism (σD) is inde-pendent of the assumed parity of the dibaryon.The fact that the total cross section (σtot) doesdepend on the parity of the dibaryon showsthat there is a strong interference between thedibaryon and the bremsstrahlung amplitude.To express this more clearly we have plottedin Figure 2 the cross section ratio’s

Pk =σk

σtot, (1)

where the index k = D or γγ. Further we alsodefine

P =σtot

σD + σγγ. (2)

This last quantity shows most clearly the ef-fects of interference. A more complete accountof this work is given in ref. [2].

[1] O. Scholten, A.Yu. Korchin, Phys. Rev. C 65,054004 (2002).

[2] O. Scholten, Ojwang J.G.O., S. Tamenaga,Submitted to Phys Rev C.

37

3.5 Neutron-proton mass difference in chiral perturbation theoryand nuclear forces

R. G. E. Timmermans, J. L. Friar a), U. van Kolck b), M. C. M. Rentmeester c)

Isospin violation in nuclear physics has un-dergone a renaissance because of Chiral Per-turbation Theory (χPT), which includes anunderlying power counting based on the sym-metries and scales of QCD, and allows a sys-tematic organization of calculations. The rel-evant scales for constructing nuclear poten-tials include the pion decay constant, fπ ∼93 MeV, which sets the scale for pion emis-sion, the pion mass, mπ, which sets the scalefor chiral-symmetry breaking, the typical nu-cleon momentum, Q ∼ mπ, which is an inversecorrelation length in nuclei, and the charac-teristic QCD scale, Λ ∼ mρ. Heavy mesonsand baryons are frozen out, although their ef-fect is present in the counterterms of the effec-tive interactions. The resulting field theory isa power series in Q/Λ, and the number of pow-ers of 1/Λ (e.g., n) is used to label individualterms in the Lagrangian (viz., L(n)).

Originally χPT was applied to ordinary(“Class I”) strong forces. More recently it hasbeen extended to incorporate isospin viola-tion in nuclear forces, and applied to charge-independence breaking (CIB) forces (ClassII) and ordinary charge-symmetry breaking(CSB) forces (Class III). In Ref. [1] the list wascompleted with CSB forces that lead to tran-sitions between I = 0 and I = 1 np states only(Class IV). These forces satisfy (in magnitude)Class I > Class II > Class III > Class IV. Themass difference between the proton and neu-tron plays an important role in CSB. It arisesfrom two separate physical mechanisms: theup-down quark-mass difference md−mu, whichdominates and makes the neutron heavier thanthe proton, and hard electromagnetic (EM) in-teractions at the quark level, which tends tomake the proton heavier than the neutron.The dimensionless parameter associated withup-down quark-mass-difference isospin viola-tion is ε m2

π/Λ2 ∼ 1%, where ε = md−mu

md+mu∼ 0.3.

The parameter associated with hard EM in-teractions is α/π ∼ 0.25%.

In Ref. [1] a new method was developed fortreating the effect of the neutron-proton massdifference in isospin-violating nuclear forces. Afield redefinition was used to remove that massdifference from the Lagrangian (and hencefrom asymptotic nucleon states) and replaceits effect by effective interactions. Previouscalculations of static Class II CIB and ClassIII CSB potentials were verified using the newscheme, which was then used to calculate ClassIV nuclear forces. The dominant Class IV force(n = 2) is generated by one-pion exchange. Itsorigin can be understood in simple terms fromGalilean covariance. The center-of-mass of thesystem is slightly closer to the neutron than theproton because the neutron is heavier. The ex-change of a charged pion interchanges the neu-tron and the proton, which causes the CM tomove (slightly) further from the origin. Thus,with differing neutron and proton masses theusual CM does not move in a straight line inthe absence of an external force.

The leading-order short-range Class IVCSB interaction is of order n = 4. The ori-gin of this interaction cannot be asserted fromthe symmetries of QCD, and therefore dependson the details of the QCD short-range dynam-ics. In the existing literature, this interactionhas been modeled by e.g. ρ-ω mixing. In ad-dition, there exist Class IV forces from pho-ton exchange. The dominant one is due tothe magnetic moment of the neutron interact-ing with the charge of the proton in np scat-tering. This interaction is O(Q2/M2

N) smallerthan Coulomb exchange. If one takes α/π asεm3

π/Λ3, this interaction counts as n = 3.

a) Los Alamos National Laboratory, U. S. A.b) University of Arizona, Tucson, U. S. A.c) University of Nijmegen, the Netherlands.[1] J. L. Friar, U. van Kolck, M. C. M. Rent-

meester, R. G. E. Timmermans, Phys. Rev.C 70, 044001 (2004).

38

3.6 KΛ and KΣ photo-production in a coupled channels framework

Alexander Usov, Olaf Scholten

Results are presented for photo-inducedKΛ and KΣ production of the proton up toan energy of

√s ≤ 2 GeV. In the calculation a

gauge-invariant coupled channels formalism isused, based on an effective Lagrangian model.Coupled channels effects are implemented viathe K-matrix formalism. The model includesγN , πN , ηN , φN , KΛ and KΣ asymptoticstates and a number of resonances as interme-diate states. Also the ρN channel was includedto estimate the effects of the omitted 2πN finalstates.

To illustrate the effects of the channel cou-pling the calculated cross-section for the KΛphoto-production is shown in the Figure 1.Note that the zero-point is suppressed in theplot. The final calculation (solid line) is com-pared to calculations where the model parame-ters are modified in a such way that the directcontributions remain unchanged and only re-scattering effects are modified.

• The dashed line in the left panel of Fig-ure 1 corresponds to a calculation in whichthe photon-nucleon coupling constant for theS11(1690) resonance, gS

Nγ , is decreased by afactor 9 and the kaon coupling, gS

KΛ, increasedby the same factor such that its leading or-der contribution to the γ + p → K + Λ re-mains unchanged. This strongly suppressesthe contributions to the pion photo-productionand η photo-production channels. The dif-ference with the solid line thus shows clearlythe coupled-channels effects through this res-onance. While the full calculation shows thepeak at 1.7 GeV, it is missing in the dashedcalculation which shows that it is not due toa direct contribution from the resonance, butthat re-scattering effects are essential in its for-mation.

• The dotted line represents the results of acalculation in which the ρ-meson final states

have been excluded from the model space. Theopening of the ρ-meson channel takes flux awayfrom the KΛ-channel thus depleting the crosssection near the threshold.

• The dashed line in the right panel of Figure 1corresponds to a calculation in which the signsof the η coupling-constants for both S11 res-onances have been changed. In leading orderthis only changes the interference pattern forthe N − η final state and has no effect on anyother channel. As can be seen the effects ofchannel-coupling are large, even for this subtlechange in coupling constants.

• The dotted line in the right panel shows theresult when the pion-coupling constant for theP13(1750) is set to zero, gP

Nπ = 0. In the ab-sence of channel-coupling effects this shouldnot have any influence on the γ + p → K + Λchannel, still this has an observable effect.

1.6 1.8 2.0 2.2W [GeV]

1.0

1.5

2.0

2.5

tot

[b]

(p, K+)

1.6 1.8 2.0 2.2W [GeV]

1.0

1.5

2.0

2.5

1.0

1.5

2.0

2.5(p, K+)

Figure 1: Illustration of the channel couplings effects.See the text for details.

We have shown that the channel couplingeffects are of a large importance in the calcula-tion of cross-sections. In addition they imposeadditional constrains on the model parameters.

[1] The article is to be published soon. Asomewhat more complete description can befound in the proceedings of the FB19 confer-ence.

39

40

Chapter 4

Atomic Physics

41

4.1 Reduced electronic stopping in laser excited fullerenes

Fresia Alvarado, Ronnie Hoekstra, Reinhard Morgenstern, Thomas Schlatholter

One of the most remarkable features ofC60 is its response to excitation. For low in-ternal energies, ionisation and C2 evaporationare competing processes. If the excitation ison the order of 80 eV, multi-fragmentationinto smaller cluster ions becomes an importantchannel [1].

Possible ways of exciting fullerenes are col-lisions with ions or multiphoton excitation us-ing pulsed lasers. For ion energies in thekeV regime, the main excitation mechanismis the so-called electronic stopping, i.e. elec-tronic friction of the ion in the electron gas ofthe fullerene leading to electronic excitationswithin the latter. In the case of multiphotonexcitation, the primary step is electronic exci-tation of the target as well .

In earlier studies on He+ collisions withfullerenes, we found the C60 multifragmenta-tion yield to scale with the electronic stoppingof the ion in the electron gas of the fullerene[2]. Theoretical studies using a non-adiabaticquantum molecular dynamics technique notonly confirmed these findings but also foundthe electronic stopping in C60 to be fundamen-tally different from the electronic stopping insolids [3].

We investigated the influence of the pres-ence of an electronic excitiation in thefullerene’s electron gas on the electronic stop-ping of He+ ions. To this end, C60 was mul-tiphoton excited to just below the ionizationthreshold by means of 5 ns pulses from a fre-quency doubled Nd-YAG laser. High resolu-

tion time–of–flight (TOF) spectrometry wasused to investigate the response of the excitedspecies to interactions with keV He+ ions.

A strong increase of multifragmentationwas observed when comparing collisions withordinary C60 to those with the laser–excitedfullerenes, as shown in Figure 1. From a com-parison of both data sets we estimated the dif-ference in electronic stopping of He+ ions forinteractions with C60 valence electrons in theground state and in excited states. This waywe could for the first time demonstrate experi-mentally a reduction of the electronic stoppingin the photo-excited fullerene [4].

Figure 1: TOF spectra of the products from 7 keVHe+ collisions with C60, the lowest spectrum (c) showsthe difference between laser off (a) and laser on (b)

[1] D. Muigg et al., J. Phys. B 29, 5193 (1996).[2] T. Schlatholter et al., Phys. Rev. Lett. 82, 73

(1999).[3] T. Kunert and R. Schmidt, Phys. Rev. Lett.

86, 5258 (2001).[4] F. Alvarado et al., J. Phys. B 38, L55 (2005).

42

4.2 Ion – biomolecule interactions and radiation damage

Fresia Alvarado, Ronnie Hoekstra, Thomas Schlatholter, Bruno Manila), Jimmy Rangamaa), BerndHuber a)

The biological effects of ionizing radiationin living cells are not a mere result of the di-rect impact of high energy quanta of radia-tion. Secondary particles such as low energyelectrons, radicals and (multiply charged) ionsare formed within the track of the ionizingparticle. The interaction of these secondaryparticles with biologically relevant moleculesis responsible for a large fraction of the bi-ological damage caused to a cell. Moleculeswithin a cell can be subject to core ionizationby a primary particle and subsequent Auger-cascades lead to formation of multiply chargedions. These ions in turn can interact e.g. withDNA constituents.

In this context, multiply charged ions(MCI) are of importance as secondary as wellas primary particles. As primary particles, forinstance Cq+ ions are used in heavy ion ther-apy and also play a role in radiation exposureof biological tissue in space.

10 20 30 40 50 60 70 80 90 100 110 1200.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

24 keV C+

, isolated molecule

20 keV O5+

, cluster

Rel

ativ

ein

tensi

ty

m/q

Figure 1: Mass per charge spectrum of the uracilfragmentation products after collisions with MCI. Thecircled peak indicates channels only observed in theclusters case.

We investigate the interaction of slow mul-tiply charged ions (MCI) with nucleobases andtheir clusters as model systems for DNA. Theions, extracted from the ECRIS at KVI andthe ECRIS at GANIL are collided with the gasphase targets. The collision products are ex-tracted by means of a static electric field andfragmentation is studied by coincidence time–of–flight spectrometry. The measured spectraare essentially bimodal with a peak due to the

parent ion (m/q = 112) and a broad distri-bution of small fragments [1]. Intact ions areformed in gentle overbarrier-like capture pro-cesses, whereas multifragmentation after closecollisions leads to a broad distribution of smallfragments. Triple coincidence studies revealthe origin of the most prominent peaks in theintermediate region: They are involved in two-body breakup processes after two- (or one-)electron capture processes.

For the RNA base uracil, fragmentation al-ways implies destruction of the ring, whereasfor thymine also removal of atoms from outsidethe ring is observed [2]. In studies on uracilclusters, the effect of a surrounding mediumon ion-induced fragmentation can be studied.Fragmentation channels forbidden in the iso-lated molecule open up in that case (Figure 1).

Furthermore, (thyminenadeninem)+ clus-ter ions were found to follow non-statisticalm/q distributions (see Figure 2). The magicnumbers might be fingerprints of their geomet-ric and electronic structure. Particularly thelatter is exciting because of the possibility ofWatson-Crick type hydrogen bonding knownfrom DNA.

Figure 2: Mass per charge spectrum obtained from agaseous mixture of adenine + thymine with Xe+21 ionsof energy 420 keV at GANIL, Caen

a) CIRIL-GANIL, Caen Cedex, France.[1] J. de Vries et al., Eur. Phys. J. D 24, 161

(2003).[2] T. Schlatholter et al., NIMB, in press.

43

4.3 Charge Exchange in Cometary Atmospheres

Dennis Bodewits, Xander Tielensa and Ronnie Hoekstra

Comets are bright emitters in X-ray andFar-Ultraviolet (XUV). The main driver ofthis emission is charge exchange between solarwind ions and neutrals in the cometary coma.We study these reactions in the laboratory anduse our results to model cometary XUV emis-sion. With these models, we have been able todemonstrate that cometary XUV emission de-pends on properties of both the comet (gas pro-duction rate, composition, distance to the sun)and the solar wind (speed, composition)[1].

We assume that a comet has a sphericallyexpanding neutral coma, that interacts withsolar wind ions, penetrating from the sunwardside following straight line trajectories. In ourcalculations, the evolution of the charge statedistribution of the solar wind ions is followed asthey capture electrons from cometary neutrals(Figure 1). Because oxygen ions have muchlarger cross sections for electron capture thancarbon ions, carbon ions are found to penetratedeeply into the cometary atmosphere whereasoxygen is depleted in the outer regions of thecoma.

−106

−105

−104

−103

−102

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

Distance to the Nucleus (km)

Fra

ctio

n

O8+

C6+

C5+

O7+

Figure 1: Charge state distribution of slow solar windcarbon and oxygen ions flying along the comet-Sun axisthrough a Halley type comet (Q = 1029mol./s of which10% CO) at a distance of 1A.U. to the Sun.

300 400 500 600 700 800 900 10000

0.2

0.4

0.6

0.8

1

1.2x 10

−3

Photon Energy (eV)

Nor

mal

ized

Inte

nsity

CV

CVI

CVI

OVII

OVIII

OVIIOVIII

Figure 2: Synthetic spectrum for a Halley type comet.Spectra were modelled for three different types of solarwind. The solid black line indicates a spectrum due toslow wind, the dashed grey line is for fast wind and thedotted line is for a decelerated wind.

The last step is to model emission spectraof the ions involved. Cascade spectra are cal-culated for all the ions tracked in the coma.Resulting spectra for a slow, fast and deceler-ated solar wind are shown in Figure 2. Themodel shows that fast wind spectra are domi-nated by carbon emission below 500 eV, whileslow wind spectra are dominated by oxygenemission above 500 eV.

In May 2005 the Japanese Astro-E2 X-ray satellite will be launched. This observa-tory will provide spectral images with such ahigh spectral resolution that fully resolved lineemission spectra become feasible. An interdis-ciplinary effort is therefore called for to enablethe use of cometary XUV emission as a newwindow on the complex interaction betweencomets and the solar wind.

a) Kapteyn Astronomical Institute, Rijks-universiteit Groningen

[1] D. Bodewits, Z. Juhasz, R. Hoekstra andA.G.G.M. Tielens, Ap.J. Lett. 606, 81(2004).

44

4.4 Direct observation of pure one-electron capture from the targetinner-shell in low-energy p +Na collisions

Steven Knoop, Myroslav Zapukhlyaka), Tom Kirchnera), Hans Jurgen Luddeb), Reinhard Morgenstern,Ronnie Hoekstra

Inner-shell processes in ion-atom collisionsare usually studied at high energy (0.1-10MeV), where the projectile velocity is in arange where it ”matches” the orbital veloc-ity of the inner-shell electrons. At low en-ergy those processes are overwhelmed by outer-shell processes and therefore difficult to inves-tigate. We succeeded in direct observation ofinner-shell capture (ISC) in low energy colli-sions using the technique of MOTRIMS (Mag-neto Optical Trapping Recoil Ion MomentumSpectroscopy).

Figure 1: Q-value spectrum of Na+ recoil ions from14 keV p +Na collisions. The main contributions comefrom outer-shell capture (OSC), of which capture intoH(n = 1) and H(n = 2) are indicated. Outer-shellionization starts beyond Q = 5.14 eV. On top of theionization tail the inner-shell capture (ISC) contribu-tion appears.

We have measured electron capture andionization processes in p +Na collision at 4-25 keV projectile energies. Besides processesinvolving only the outer-shell electron (whichdominate in this energy range), Na+ recoilsproduced by transfer of one of the Na 2p inner-shell electrons into the H(n=1) state were de-tected [1]. The target recoil ion is mainly left inthe excited Na+(2p53s) and Na+(2p53p) states(see Figure 1).

While the 2p53s configuration suggeststhat the outer electron acts as a spectator, the

2p53p configuration implies an active partici-pation of the outer electron during inner-shellcapture. With increasing projectile energies weobserve a decrease in 2p53p relative to 2p53s.Quantum mechanical calculations within theindependent particle model have been carriedout for all target electrons in order to studythe electron capture and ionization processesinvolving the different electron shells. The cal-culations show that ISC dominates single elec-tron capture (SEC) above E = 40 keV (Figure2). Previous theoretical approaches includedonly the outer-shell electron and could neverfind agreement with experimental data.

Figure 2: Absolute cross sections in p +Na collisionscontaining total SEC, OSC and ISC. Closed symbols:present data. Lines: theory. Open symbols: DuBois[2].

a) Institut fur Theoretische Physik, TechnischeUniversitat Clausthal, Germany.

b) Institut fur Theoretische Physik, UniversitatFrankfurt, Germany.

[1] S. Knoop, R. Morgenstern, R. Hoekstra, Phys.Rev. A. 70, R050702 (2004).

[2] R. D. DuBois, Phys. Rev. A 34, 2738 (1986).

45

4.5 One electron capture and ionization in collisions between highlycharged ions and Na

Steven Knoop, Gabriel Valeriu Hasan, Herwig Ott, Matthias Keima), Hans Jurgen Luddea), RonOlsonb), Reinhard Morgenstern, Ronnie Hoekstra

With the technique of MOTRIMS thatcombines laser-cooling and trapping of atoms(Magneto-Optical Trapping) with preciseimaging of small target recoil momenta (Re-coil Ion Momentum Spectroscopy), we havemeasured one electron capture and ionizationprocesses in several collision systems, namelyH+[1], He2+ and O6+ on Na. State selectiveas well as differential cross sections are ob-tained from the recoil spectra. First experi-ments including excited Na atoms show thatwe can separate events resulting from Na(3p)and Na(3s). This is the first step towards mea-surements with aligned Na(3p) target atoms.

Figure 1: A longitudinal momentum spectrum of 4keV/amu He2++Na(3s). Capture into n = 3 and n = 4can be clearly separated and capture in the weak chan-nel n = 2 can be observed.

In case of He2++Na state-selective crosssections for capture into the n = 2, 3, 4 andn > 4 as well as ionization have been ob-tained for 3-13 keV/amu collision energiesand compared with Classical Trajectory MonteCarlo (CTMC) calculations. It was found thatCMTC agrees well with experiment for cap-ture into the high states (n = 4 and n > 4),but overestimates the weak capture into n =2. Concerning ionization good agreement isfound, especially with respect to the energydependence.

In the O6++Na collision system, state se-

lective cross sections for capture into the n =5, 6, 7, 8 and n > 8 states of O5+ have been ob-tained in the 1-9 keV/amu energy range. Ex-perimental data is compared with both CTMCand Atomic Orbital (AO) calculations. AOperforms slightly better than CTMC, for theweak n = 5 channel, but the oscillations asfunction of energy observed for the n > 8 chan-nel are better reproduced by CTMC than AO.

Figure 2: Energy loss spectrum of Na+ recoil ionsafter O6++Na collisions at 2.25 keV/amu collision en-ergy. Capture into the different n-states of O5+(1s2nl)can be clearly resolved. Main capture channel is captureinto n = 7, while also n = 6 and n = 8 contribute.

Recently we have started measurements onXe18++Na collisions. To our knowledge thisis the first measurement of collisions betweenhighly charged ions with q > 10 and Na. Theresulting Na+ recoils show large (negative) lon-gitudinal momenta. Capture takes place intovery high n-states (n = 14 − 18). For cap-ture into these high n-states AO calculationsare not feasible and one has to do CTMC typecalculations.

a) Institut fur Theoretische Physik, UniversitatFrankfurt, Germany.

b) Physics Department, University of Missouri-Rolla, USA.

[1] S. Knoop, R. Morgenstern, R. Hoekstra, Phys.Rev. A. 70, R050702 (2004).

46

4.6 Repump-enhanced Single Atom Detection

Albert K. Mollema, Steven Hoekstra, Herwig Ott, Lorenz Willmann, Hans Wilschut, Reinhard Mor-genstern, Ronnie Hoekstra

Atom Trap Trace Analysis (ATTA) is a re-cently developed mass spectrometry methodusing cooling and trapping techniques. It canbe used to precisely determine the fraction ofrare, long-lived isotopes in samples of elementsthat are accessible for laser cooling techniques.Calcium is the element under consideration inthe Al41Catraz experiment [1]. Application ofATTA to the rare calcium isotope 41Ca caneventually be used in the fields of geology (dat-ing) and medicine (tracing).

In the Al41Catraz experiment, Ca atomsfrom a metallic sample are evaporated from anoven, which is typically operated at a tempera-ture of 400 C. Atoms leave the oven at typicalvelocities on the order of 600 m/s. The atomsare slowed down in a Zeeman slower and de-flected over an angle of 30 using an opticalmolasses. Finally, the atoms are trapped ina Magneto Optical Trap (MOT). The fluores-cence in the trap is measured using a photondetector. The detection of 41Ca in natural Cacontaining samples is an enormous challengebecause its abundance is on the order of 10−14

only. Given this extremely low abundance, it isessential that single atoms can be detected inthe trap. In the course of 2003, the first single40Ca atom measurements were done, showingtypical trapping times of 20 ms. The time a Caatom can be trapped in a MOT is mainly lim-ited by the fact that the cooling transition (423nm 4s1S0 - 4p1P1) is not completely “water-tight”. On average, once every 105 cycles, anexcited atom may decay to the 1D2 state andfrom there to metastable 3P states, removingit from the cooling and trapping processes.

In 2004, a so called repump laser was in-stalled to circumvent this loss process. Using672 nm laser light, atoms are pumped from the3d 1D2 to the 5p 1P1 state, from where they de-cay to the 4s 1S0 ground state, so they return inthe cooling and trapping cycle. Measurementsof the trapping times of both an ensemble of

atoms and single atom events of 40Ca show anenhancement by a factor of 8 to trapping timesof ∼ 160 ms (see Figures).

Next year, we plan to do repump-enhancedtrapping time measurements on 43Ca. Sinceodd isotopes of Calcium have nuclear spin, the1D2 - 1P1 transition has a complex hyperfinestructure, complicating the repumping.

Figure 1: Exponential decay with a decay time of 160ms of trap fluorescence after terminating the atomicbeam flux into the trap.

Figure 2: Autocorrelation of single atom data (dots),fitted with an exponential function with a decay time of157 ms. (solid line).

[1] S. Hoekstra et al., Phys. Rev. A, 71, 023409(2005).

47

4.7 Spin filtering in electron capture from surfaces

Mirko Unipan, Abel Robin, Reinhard Morgenstern, Ronnie Hoekstra

Surfaces and thin films often have mag-netic properties which are drastically differ-ent from those of the bulk or of the under-lying substrate. For example, a FeO film hasan anti-ferromagnetic coupling to the Fe sub-strate on which it was grown; Ru, which isnon-magnetic, becomes magnetic when grownas a thin film. These properties often dependon the structure, thickness and temperature ofthe surface or thin film. Such effects are dueto the different electronic structure and the re-duced dimensionality of the surfaces.

Figure 1: The difference in the degree of circular po-larization of the HeI 3D line, for magnetization paralleland anti-parallel to the z axis (which is perpendicularto the beam direction and contained in the sample sur-face). The incidence angle of the ion beam was 5 withrespect to the sample surface.

Grazing incidence keV ion beams interactonly with the topmost surface layer, makingthem a suitable tool for observing surface ef-fects. A fraction of the ions is neutralized intoexcited states. The spin direction of the cap-tured electron is being conserved. The subse-quent photon emission from the excited projec-tiles is partially polarized. The degree of cir-cular polarization is related to the magnetismof the surface [1,2]. Using singly-charged ions,this method, called ECS (Electron CaptureSpectroscopy), was successfully applied in par-

ticular to Fe(110), where it was shown that thesurface spin polarization is consistent with ahigher density of states (DOS) for the major-ity electrons at the Fermi energy. In this re-spect, studying Ni(110) is interesting because,according to calculations, a much higher den-sity of states for minority than for majorityelectrons is predicted at the Fermi energy [3].

Here we compare results on the magne-tization of Fe(110) and Ni(110) surfaces ob-tained by using keV He+ ions scattered graz-ingly from the sample surfaces, and detectingparallel to the surface the light emission fromthe (1s3d) 3D → (1s2p) 3P HeI 587.5 nm line.The observed difference in the degree of circu-lar polarization when switching the magnetiza-tion parallel or anti-parallel to the z -axis (seeFigure) reflects the ratio between the numberof available majority and minority electronsaround the Fermi energy, thus the ratios in theDOS at the Fermi energy.

Our results for Fe(110) confirm previousmeasurements. For Ni(110), the effect is oppo-site as compared to Fe(110), indicating that atthe Fermi energy the minority electrons have ahigher DOS than the majority electrons. Fromdensity of states calculations, one would ex-pect a stronger effect in Ni than in Fe. Theexperimental net effect of spin polarization,though, is of comparable strength for both sur-faces, hinting at a strong spin-filtering mech-anism. For both surfaces there are empty mi-nority electron states above the Fermi energy,while the majority electron states are belowthe Fermi energy and are occupied. In thisway minority spins can be recaptured from theprojectile back to the surface, reducing the ob-served negative polarization for Ni(110) andenhancing the positive one for Fe(110).

[1] M. Unipan et. al., ”Transfer of spin polar-ization in ion-surface scattering”, NIMB (inpress).

[2] H. Winter, Phys. Rep. 367, 387 (2002).[3] F. Mittendorfer et. al., Surf. Sci. 423, 1

(1999).

48

Chapter 5

Nuclear Geophysics

49

5.1 Earth AntineutRino TomograpHy (EARTH).

R.J. de Meijer

In the year 2004 the KVI has been ex-ploring new opportunities for its research andtechnology programme. One of the items isthe development of modular detector systemsfor directional sensitive detection of low-energy(<50MeV) antineutrinos. Antineutrinos areproduced in the decay of natural radionuclides,in fission processes and by the spin-flavour pre-cession of neutrinos. The availability of suchdetectors would add a new dimension to thelarge detector set-ups. Applications for suchdetectors come in fundamental physics (sub-dominant mixing angle θ13), astrophysics, re-actor physics, security and geophysics.

The programme EARTH takes the geo-physics topic as its main issue, without ignor-ing the other options. Its goal is to make a to-mographic image of the interior of our planetby measuring with directional sensitive detec-tors the antineutrinos at about ten locations atthe Earth’s surface. Each location will have anantenna consisting of about thirty arms, drilledinto the surface to a depth of 1.5 to 2 km. Eacharm points into a particular direction of the in-terior and contains a multitude of directionalsensitive detectors. Each antenna will have adetector mass of about four kilotonnes.

The programme has a number of phaseseach ending with a clear go/ no-go decision.The costs at each next step will increase, butat a reduced risk since the previous phase hasbeen concluded successfully. The preparationsof the programme were made in a close col-laboration with the University of Cape Townand iThemba LABS, South Africa. The firstphase could start on 1 September 2004 afterthe Dutch astronomy organisation ASTRONand the Rijksuniversiteit Groningen/KVI hadgranted a start-up funding. In addition, theSouth African National Research Foundationpromised to contribute to the initial phase.

After the start the scientific and technolog-ical topics focused on the feasibility of a direc-tional sensitive detector and the location of a

suitable site for the first antenna, preferablywithin the Netherlands but with proper char-acteristics qua drilling and qua background.Such an antineutrino detector is physics-wisefeasible with a high degree of directionality [1].Directionality is feasible due to the kinematicsof the capture reaction of the antineutrino byH, and the application of 10B in the detectormaterial. The 10B captures the neutron be-fore it is thermalised and emits an α-particle,thereby preserving the forward peaking of theneutron. The next stage is building a numberof such detectors and testing them and theirvarious possible background reduction tech-niques near a nuclear reactor. In September2004 we met with six enterprises in the Nether-lands, each with products related to the detailsof a future antineutrino detector. Already inthe next stage we start to work together in aconsortium to build and test the set of detec-tors.

In parallel to the detector development wemade progress on the site location and thedrilling technology. After a quick scan ofthe possibilities the Dutch Antillean island ofCuracao emerged as the most suitable location[2]. This choice was very much welcomed bythe government of the Dutch Antilles becauseit will also leads to a scientific centre on theisland and an opportunity for employment ofAntillean scientist and engineers. The govern-ment sees the programme EARTH as a stepin their programme for the Antilles to becomethe islands of Education and Sophistication.

At the end of 2004 the EARTH team con-sists of ten scientists of the KVI, four scientistsin South Africa and eight industries and is ad-vised by a board of five distinguished personsfrom various disciplines.

[1] H.J. Wortche et al., this report, contribu-tion 5.2.

[2] E.R. van der Graaf et al., this report, contri-bution 5.3.

50

5.2 Feasibility of a directional sensitive antineutrino detector

H.J. Wortche, R.W. Fearicka), R.J. de Meijer, F.D. Smitb), M. Maucec, F.D. Brooksa)

The presented work is part of the EARTHprogramme which focuses on the location ofradiogenic heat sources in the Earth’s interiorby measuring low-energy electron antineutri-nos originating from nuclear decay processes.Due to their minimal interaction with mat-ter (anti)neutrinos can pass through the Earthwith virtually no change of their primary direc-tion. We envisage installation of a world-widenetwork of detectors(antennas) built of mod-ules which have an enhanced sensitivity for thedetection of antineutrinos in the axial direction[1]. As pointed out by Fields and Hochmuth[2] directional sensitive measurements of geo-antineutrinos would provide a unique way toprobe deep geothermal heating processes. Thedetection will proceed via the inverse β-decay

νe + p + 1.806 MeV → e+ + n , (1)

in which the neutron is ejected more or lessalong the trajectory of the incoming antineu-trino while for energies below 20 MeV thepositron exhibits a rather isotropic angular dis-tribution. Existing detector setups consist ofmonolithic, large-volume detectors containingeither H or Gd for capturing the thermalisedneutrons originating from reaction Eq.(1) anddetecting the Compton electrons of the γ-rays. Since thermalised neutrons rapidly losetheir memory of the emission angle and sincethe Compton electrons are produced in a vol-ume exceeding the reaction topology, the di-rectional sensitivity of existing monolithic de-tectors is rather limited, if feasible at all. Wepresently investigate options offered by small-sized tubular detectors filled with a 10B loadedliquid scintillator. Neutron capture by 10Bleads to 7Li and an α-particle, which both arestopped instantaneously. To investigate the di-rectional sensitivity of the detector tubes, weperformed Monte Carlo simulations based onthe kinematics of reaction Eq.(1) and the sub-sequent neutron moderation to deduce the lon-gitudinal and transverse distributions of neu-trons for plain and loaded liquid scintillators.The simulations show that the number of scat-

ters that the neutron undergoes is reduced bya factor of two in liquid scintillator loaded with5% 10B due to the 1/vneutron dependence of thecapture cross section. The reduced number ofscatters results also in more compact longitu-dinal and transverse distributions of the loca-tion where the neutrons get captured, therebybetter preserving the original emission angle.

0

20

40

60

80

100

-80 -60 -40 -20 0 20 40 60 80

prob

abili

ty n

eutr

on in

side

det

ecto

r vo

lum

e [%

]

angle, measured vs axial direction [deg]

reactor neutrinos, 10mm x 10mm20mm x 20mm30mm x 30mm40mm x 40mm

Figure 1: Probability for detection of a neutron origi-nating from reaction Eq.1 assuming a reactor antineu-trino spectrum.

For a number of diameters by fixed lengththe probability for neutron detection inside thedetector volume has been calculated (Fig. 1).The result clearly indicates that directionalityis only feasible with a manifold of small sizeddetectors which will require the optimization ofthe design to combine directionality with pos-sibly high efficiency. For a volume of a detec-tor like KamLAND the number of detectorsbecomes huge. The results indicate howeverthat with large monolithic volumes no direc-tional sensitivity may be expected and hencethere is no other way out than to solve the newchallenges, especially with respect to readoutelectronics.

a) Physics Department, University of Cape TownRondebosch, South Africa.

b) IThemba LABS, Somerset West, South Africa.[1] R.J. de Meijer et al., Nucl. Phys. News Int.

14/2, 20 (2004).[2] B. Fields and K.A. Hochmuth, submitted to

Phys. Rev. D, arXiv:hep-ph/0406001.

51

5.3 Geological considerations on the location of the EARTH an-tenna on Curacao

E.R. van der Graaf, R.J. de Meijer

The EARTH research programme aims atestablishing a tomographic image of the radio-genic heat sources in the Earth [1]. This to-mography will be based on measurements witha network of underground antineutrino anten-nas. These antennas should preferably be dis-tant from nuclear reactors and large graniteformations as these give rise to antineutrinoswith a similar energy as those originating fromthe inner parts of the Earth. Curacao fulfilsthese conditions and is considered as the pri-mary location for the first antenna. However,the island does not have a uniform geologyand to locate the optimum position of the an-tenna a short inventory of Curacao’s geologywas made. Curacao (Fig. 1) consists of fourmain geological formations:

the Curacao Lava formation: This is partof Cretaceous volcanic succession consistingmainly of pillow basalts from underwater lavaoutflow about 90 Ma ago at the position ofthe present Galapagos hot spot. This formeda large oceanic plate that became buoyant andwas forced between North and South America.The Curacao Lava formation is at least 5 kmthick; the other three formations are uncon-formably later deposits.

the Knip formation: The Knip formation(Fig. 2) was formed about 75 Ma ago and con-sists of sedimentary limestone rocks and con-tains also some volcanic rocks which probablyoriginate from the volcanic after phase and alsosome basalt fragments (breccias) that are mostlikely products of erosion of the Curacao LavaFormation. The Knip formation is estimatedto be almost 2000 m thick.

the Middle Curacao formation: This for-mation was formed approximately 65 Ma agoand consists of relatively thin layers of shaleand sandstone.

the Seroe Domi formation and terrace de-posits: These are relatively young Eocene,Quaternary and Neogene deposits (Fig. 1) andoriginate from reef growth and erosion starting5 Ma ago.

The last two formations do not extend tosufficient depth to host the antenna. Econom-ically, it is advantageous to position the an-tenna in soft host rock as this would reduce thedrilling costs substantially. This favours thesofter limestone of the Knip formation abovethe harder basaltic Curacao Lava formation.In the next stage of the project it is intendedto study the extend and presence of possiblebasaltic intrusion of the Knip formation byseismology and test drills.

Figure 1: Geological map of Curacao. Taken from [2]

Figure 2: View of the Knip formation, candidate lo-cation for the Earth antenna.

[1] R.J. de Meijer et al., KVI Annual Report, 76(2003).

[2] A.C. Kerr er al., Contrib. Mineral Petrol, 124,24 (1996).

52

5.4 Monitoring nuclear fuel with antineutrinos

E.R. van der Graaf, R.J. de Meijer, S.T. van Tuinena), A. Hogenbirka)

The fission products resulting from theburning of nuclear fuel are mostly neutron richunstable isotopes that decay to more stableisotopes by β-decay. In each of these decaysalso (electron) antineutrinos are emitted. Thetotal amount and energy-spectrum of the an-tineutrinos depend on the ratios of the fission-ing isotopes in the fuel. Consequently, a mea-surement of the reactor antineutrino spectrumprovides a non-intrusive means to obtain infor-mation on the composition of the reactor core.

This project proposes to design, built andtest a prototype of a compact directional sensi-tive antineutrino detector (see [1] for the prin-ciples of detection) suitable to measure the an-tineutrino spectrum from a single nuclear re-actor in a multi-reactor plant.

We calculated the expected count rate ina compact 1000 kg detector (approximately 1m3 liquid scintillator with H/C ratio of 2) ata distance of 10 meters from a 3 GW (ther-mal) reactor to be approximately 3000-4000per hour. The expected spectrum was calcu-lated as the sum of the spectra of the four ma-jor core components (235U, 239Pu, 238U, 241Pu)folded with the cross section of the detectionreaction at the start (initial stage) and end (fi-nal stage) of a 200 days nuclear burnup op-eration. The total spectrum is mainly con-stituted by the sum of the spectra from 235Uand 239Pu (Figure 1). The total count ratein the energy interval between 2 and 8 MeVdecreases from 1.17 cps (initial stage) to 1.13cps (final stage). Collecting data for 24 hours(1 week) these count rates can be measuredwith approximately 0.3 (0.1)% accuracy. Alsothe shape of the spectrum changes becausethe contribution of 235U decreases and that of239Pu increases, effectively making the totalantineutrino spectrum softer. This is clearlyvisible in the final-to-initial stage ratio of thetotal antineutrino spectrum (Figure 2).

In conclusion, the changes in the antineu-trino spectrum during nuclear fuel burning,supply information on the composition of thefuel. Furthermore, considering the magnitudeof the expected count rates these changes are

sufficiently pronounced to make on-line (day-to-day) monitoring of the core composition fea-sible.

cps

per

MeV

0.0

0.1

0.2

0.3

total (1.17 cps)235U (0.83 cps)239Pu (0.19 cps)

Eν (MeV)

2 3 4 5 6 7 8

cps

per

MeV

0.0

0.1

0.2

0.3

total (1.13 cps)235U (0.64 cps) 239Pu (0.29 cps)

final stage

initial stage

Figure 1: Total initial (top) and final (bottom) stageantineutrino spectrum.

Eν (MeV)

2 3 4 5 6 7 8

rati

o fi

nal-

to-i

niti

al s

pect

rum

0.90

0.92

0.94

0.96

0.98

1.00

Figure 2: Ratio of final to initial stage spectra. Dottedline: no change (ratio is 1). Th dashed line is a linearadaptation to the calculated situation (solid line).

a) Nuclear Research Group, Petten, The Nether-lands.

[1] H.J. Wortche et al., this report, contribu-tion 5.2.

53

5.5 Gamma-ray analysis of NuPulse data

C. Rigollet, P.P Maleka, M. Maucec, R.J. de Meijer

In the framework of the NuPulse project[1], experiments have been carried out in a con-crete tank to calibrate the gamma-ray BGOdetector. The NuPulse tool comprises a neu-tron generator (PNDT) and a selection of neu-tron and γ-ray detectors. For calibration pur-poses, the tank was filled with water and KClwas added by loads of 50 kg. For each loadof KCl (up to 275 kg), a prompt (PNDT-on)and a background (PNDT-off) spectrum wererecorded.

As more KCl is added to the water, the am-plitude of the naturally radioactive 40K peakincreases (Figure 1). All PNDT-off spectrawere analysed for their potassium content witha set of two standard spectra, which are rep-resentative of the response of the detector toa unit of activity concentration of a specificelement. In our case, we used a 40K stan-dard spectrum, calculated with MCNP and abackground spectrum of the tool in the tankcontaining water only. The latter is necessaryto obtain a good fit to the data as we cannotsimulate the intrinsic BGO background or theactivity arising from the surroundings of thedetector (mainly cosmic radiation). The otherquantity not included in the simulations relatesto the efficiency of the detector, therefore a cal-ibration factor needs to be determined to ob-tain the real activity concentration of the ele-ment. The activity concentrations from the ex-perimental spectra were compared to the onescalculated from the known activity of 1 g ofKCl (16.26 ± 0.17 Bq/kg) and the amount ofwater in the tank. The same calibration factorwas obtained for all spectra with the weightedaverage of the calibration factor 3.15 ± 0.11.In the PNDT-on spectrum acquired in wateronly, a peak is present at 2.223 MeV and isattributed to the thermal neutron-capture re-action (n, γ) on hydrogen and a double bumpis observed above 6 MeV, representative of the

fast neutron reaction 16O(n, n’γ). As the loadof KCl dissolved in water increases, the inten-sity of the H peak decreases due to the re-moval of thermal neutrons by K and Cl, whichare effective neutron absorbers. The effect ofCl on the H peak was already predicted bysimulations, carried out with the pulsed neu-tron source in the solution of KCl. In otherwords, with increasing salt concentration, theintensity of the H peak is reduced, while thestrongest Cl capture line is enhanced. The el-emental interference effects are anticipated tobecome even more dominant with higher com-plexity in field measurements. To try and cir-cumvent the elemental interference problem, itis intended to analyse the data by separatingthe contributions of the fast and slow neutrons,i.e. one standard spectrum to represent thefast neutron interactions with the elements andanother one representing the neutron capturereactions. The analysis of PNDT-on spectrafor the various loads of KCl is currently un-derway.

0 100 200 300 400C hanne l num ber

0 .001

0.01

0.1

1

10

Cou

nt r

ate

(cps

)

PND T o ff spectra

275 kg K Cl150 kg K Cl50 kg K Clw ater

Figure 1: PNDT off spectra for various loads of KCldissolved in water.

[1] C. Rigollet et al., KVI Annual Report, 74(2003).

54

5.6 Benchmark experiments: uncertainties in 16O cross-section datalibrary.

P.P. Maleka, M. Maucec, C. Rigollet, R.J. de Meijer

Where experiments are too time/moneyconsuming, or even unfeasible, simulations canplay an important role. However, for simu-lations to be accurate, both the experimentand simulations have to be consistent andthoroughly investigated. Monte Carlo simu-lations have been used successfully to bench-mark experiments for radiometric measure-ments of natural gamma radiation [1]. In thisstudy, benchmark experiments were conductedto investigate the use of Monte Carlo sim-ulations for PGNAA (Prompt Gamma Neu-tron Activation Analysis) applications in ge-ological structures. In simulations, all parti-cles are tracked from creation until terminationwith all interactions based on physics modelsand corresponding cross-sections. The cross-section data implemented in a simulation codeplay a major role in the outcome of resultsas they represent the link between the mea-sured and the predicted (calculated) observa-tions. This contribution focuses on the stan-dard cross-section data library ENDF/B-VI.2implemented in the Monte Carlo (MCNP4C)code, with special attention to 16O reac-tions with fast neutrons and correspondingsecondary-photon production (see Table 1).For modelling (thermal) neutron-capture reac-tions, the PGNAA-tailored ACTI library, com-piled from ENDF/B-VI.8 data was deployed.

Reactions Threshold energies16O(n, αγ) 13C 3 MeV16O(n, n’γ) 16O 7 MeV16O(n, pγ) 16N 10 MeV16O(n, n’αγ) 12C 12 MeV

Table 1: Neutron threshold energies.

Despite many studies, the interaction of fastneutrons with oxygen is not well known, evenat ∼14 MeV, e.g., the 16O(n, α) cross section isknown only to 20 to 30% at this energy. Also,measured photon-production cross sections for

two prominent gamma-ray lines at 3.684 and3.853 MeV in the 16O(n, αγ)13C reaction at 14MeV incident-neutron energy show differencesin published values up to a factor of 3 [1]. Thusfor materials containing oxygen, extra informa-tion and care is required to achieve an agree-ment between the measured and calculatedspectra. Presented in Figure 1 are the gamma-ray spectra for neutron interaction with water.The 16O signal due to the (n, αγ) reaction ismore pronounced in the simulated results ascompared to the measured spectrum. This no-ticeable difference between the two spectra canhamper the analysis and the de-convolutionof the final data for elemental identification.Photon-angular distribution should have lessrepercussion, as the source is almost isotropic.This result shows that the cross-section datafor 16O available in the code over-estimate thephoton production in these reactions. A de-tailed study to assess which reactions dominatethe detector response is underway. One otherpossibility is to use a gamma-ray detector withbetter resolution to identify all photon signalsin the spectrum. This will clarify if a dedi-cated cross-section data library is required forour measuring conditions.

0 2 4 6 810-2

10-1

100

101

?

16O(n,αγ)13C

16O(n,n'γ)16O & 16O(n,p)16N

1H(n,γ)

Co

un

t ra

te (

cps)

Eγ (MeV)

Calculated (simulated) Measured

Figure 1: Gamma-ray spectra for water under simu-lated and measured conditions.

[1] P.P. Maleka et al., KVI internal report, NP007.

55

5.7 First in-situ experiments with NuPulse tool

M. Maucec, R.J. de Meijer

The development of NuPulse, a non-destructive pulsed-neutron multiple detectorfor use in environmental, hydrocarbon andmineral exploration work, has entered the fieldtesting period. The first in-situ evaluation ofthe NuPulse prototypes took place in June2004 on Cyprus. The trial sites were selected inacid-mine drainage areas of the Mathiati Southand Kalavassos districts. Their close proxim-ity to the local water reservoirs is the sub-ject of environmental pollution concern. Thestreams and the ditches running from the min-ing area are highly contaminated with heavymetals such as Cu, Zn, Fe, As, U, Pb and S.The aim of the field tests was to test the opera-tion of all available NuPulse modules (∅ 23 mmNaI γ-ray detector, ∅ 50 mm stilbene fast neu-tron detector and 3He and Li(Eu) thermal neu-tron detectors) in combination with data ac-quisition software under real field conditions.Modules were connected to the pulsed-neutron(PNDT) source, emitting 14 MeV neutrons.The ∅ 50 mm BGO γ-ray detector was notavailable for the tests. The measurements werecarried out with the NuPulse device: a) placedopen-air on the dry soil surface and b) fullysubmerged in the ditch, filled with contami-nated water. As indicated in Figure 1, a distin-guishable difference in intensity and shape ofspectra, acquired in open-air and in water ex-ists, due to different physical processes takingplace during the neutron migration throughdry and wet formation and the production ofsecondary γ-rays through neutron capture andinelastic scattering events. The γ-ray spec-tra indicate the presence of two dominant ele-ments in water, hydrogen (through the ther-mal neutron-capture peak (2.2 MeV) at ap-prox. channel 220) and oxygen (via series ofgamma lines from fast neutron inelastic scat-tering, located at approx. channel 600). Dueto the small dimensions and the low photo-

efficiency at high energies of the NaI scintilla-tor, the dominant γ-ray lines are hardly dis-tinguishable from the continuum. Due to theirlower abundance in the formation (pollutedwater) the characteristic γ-lines correspondingto (metal) contaminants remain hidden in thecontinuum. While the intensity-relation be-tween the thermal neutron decay spectra takenin water and open-air is somewhat surprising(the intensity of thermal neutron signal in wa-ter should be higher than that in open-air dueto extensive neutron elastic scattering on hy-drogen) the higher decay constant in water isto be expected. The fast neutron spectra indi-cate different behaviour when acquired in wa-ter and on dry: the presence of hydrogen inwater contributes extensively to neutron scat-tering and therefore enhances the spectrum atlower energies, while the higher energy compo-nent is reduced. The first field test has shownthat NuPulse is a highly innovative project andthat several challenges have been met, but alsothat some new ones have surfaced. The ongo-ing research activities include the extractionof quantitative elemental information from themeasured spectra by advanced data interpre-tation techniques, based on the Full SpectrumAnalysis (FSA).

0 100 200 300 400 500 600 700 800 900 1000 1100100

101

102

103

Co

un

ts

Channels

water soil

Figure 1: The NuPulse spectra measured for 15 minin open-air on soil (dotted line) and submerged in water(solid line) with the γ-ray slim NaI module.

56

5.8 Fast neutron spectra measured at NGD/KVI calibration facili-ties.

P.P. Maleka, C. Rigollet, M. Maucec, M. Hevinga, R.J. de Meijer

The most common method for fast neutrondetection is based on elastic scattering of neu-trons by light nuclei. The types and concen-trations of nuclei determine the probabilitiesof the corresponding reaction. Hydrogen con-taining materials are mostly used in neutron-detector constructions. Neutrons can transferan appreciable amount of energy in one colli-sion with hydrogen or even lose up to all theirenergy. The energy ER given to the recoil nu-cleus is uniquely determined by the scatteringangle, θ:

ER =4A

(1 + A)2(cos 2θ)En (1)

where A is the mass number of the target nu-cleus and En the incoming neutron energy.A head-on-collision of the incoming neutronwith the target nucleus will lead to a recoilin the same direction (θ ∼= 0), thus resulting inthe maximum possible recoil energy. A mon-itoring tool containing a pulsed D-T neutronsource generator and a fast neutron detector(stilbene) was tested. When operational, thepulsed D-T source will generate neutrons al-most isotropically with energies of about 14.2MeV. The neutron source has a burst fre-quency of 20 Hz and emits between 107 and 108

neutrons/s. Although an organic stilbene scin-tillator has lower light output, in this project itis preferred because of its superior gamma-rayrejection characteristics.

At KVI the calibration facility, consistingof a water tank with a 2 m diameter, 3 m heightand 10 cm concrete wall was used. For the ini-tial measurement, the tool was inserted in anempty tank and thereafter in a water tank forunderwater measurement. The results (Figure1) show a clean distinction between the spectrameasured in the empty and water filled tank.The region of interest in the spectra is in thelow energy region (labelled area A in Figure 1).In this area, the count rates in the presence of

water are higher than in an empty tank. Be-cause of the high concentration of hydrogen inwater, neutron moderation is high hence lowenergy neutrons are detected as well. More-over, the tool was lowered in a borehole forfurther tests. In area A of Figure 1, the resultsalso show the presence of good moderators aswell, i.e. comparable to the water filled tank.Although the water content of the boreholematrix is unknown, observation shows about40% deviation between the borehole and waterfilled tank results. Further tests are needed toconfirm the moisture content of the boreholematrix and its relation to the current findings.If confirmed, this can be another way of usingfast neutron spectra to identify the hydrogencontent in the matrix. A calibration procedureis required for more detailed description of theentire spectrum. At present, the investigationof deploying Monte Carlo method is underway.Coupled Monte Carlo results with experimen-tal ones will give a more comprehensive ex-planation of the findings in Figure 1. Sub-sequently, the possibility of identifying othernuclei present in the matrix will also be inves-tigated. In addition to using fast neutron spec-tra for quantitative renormalization of gamma-ray spectra in terms of neutron source output,spectra can be used as complementary infor-mation for elemental analysis.

0 200 400 600 800

10-3

10-2

10-1

100

101Area A

En~ 14.2 MeV

Co

un

t ra

te (

cps)

Channel numbers

Empty tank Water filled Borehole

Figure 1: Fast neutron spectra for various measuringconditions.

57

5.9 An anticoincidence set-up for the BGO detectors in PHAROS:benchmark experiment

I. Radulescu, C. Rigollet, E. R. van der Graaf

A benchmark experiment for an anticoinci-dence system was carried out for the PHAROSdetectors in 2004. The background inducedby the interaction of cosmic rays with the de-tector and the shielding components becomesdominant when the detector components andshielding materials are carefully selected forlow radioimpurity. The influence of the cosmicrays becomes then responsible for about 40 to50% of the remaining structure of the back-ground spectrum. The induced cosmic radia-tion background can be reduced by using thedetectors deep underground or by designingan active shield, e.g. an anticoincidence set-up using plastic scintillators. The coincidencecircuit receives simultaneous pulses generatedwhen a cosmic ray passes through an overlay-ing plastic scintillator and the BGO detector.The circuit uses the prompt output from theplastic scintillator and a delayed output fromthe BGO detector, respectively as the startand stop signal for a time-to-amplitude con-verter (TAC). A TAC spectrum is showed inFigure 1. The TAC generates a pulse whoseheight is proportional to the delay betweenthe arrivals of these two pulses. For coinci-dent events in the two detectors, the TAC willoutput a pulse with a height that correspondsto the fixed time delay imposed on the BGO’ssignal. The anticoincidence measurement is setup such that whenever a pulse of a correspond-ing height (corresponding to the delay betweenthe two signals) is issued by the TAC, a blank-ing pulse is generated to momentarily disablethe input (block the ADC) and prevents theaddition of this event to the spectrum. Figure2 shows the BGO background measurementsoutside and inside of a 10 cm thickness leadshielding. The count rate was 197.4 ± 0.1 cps,11.17 ± 0.02 cps and 6.62 ± 0.01 cps, for theBGO outside the lead shielding, inside the lead

shielding and with the active shield, respec-tively. The reduction factor due to the use ofthe lead shielding is 18. Using the active shield(the plastic scintillator laying above the BGOdetector) the count rate decreases by almosta factor of two. Still, part of the remainingbackground is due to incomplete shielding. Anoptimal configuration for the anticoincidenceset-up is underway to achieve the best reduc-tion of the background for the induced cosmic-radiation in PHAROS BGO detectors.

Channels

100 200 300 400 500

Co

unt

rat

e (c

ps)

0.00

0.01

0.02

0.03

0.04

0.05

0.06

Figure 1: A TAC spectrum, showing the coincidencepeak between the plastic scintillator and the BGO de-tector.

Channels

100 200 300 400 500

Co

un

t ra

te (

cps)

1e-3

1e-2

1e-1

1e+0

(1)(2)

(3)

Figure 2: Background spectra: (1) outside the leadshielding, (2) inside the lead shielding, (3) in anticoin-cidence with the plastic detector.

58

5.10 In-situ sediment gamma-radiation at the barrier island Schier-monnikoog (NL)

A.V. de Groot, R.J. de Meijer, J.P. Bakkera), R. ten Have

Barrier islands in e.g. the Dutch WaddenSea are dynamic sediment bodies. Their sedi-ments originate from various sources and re-flect the effect of sorting processes by windand water. The variability of sediment typeson the island Schiermonnikoog was studiedusing gamma radioactivity, as the sedimentproperties grain size, provenance and watercontent determine the measured radioactivityof the sediment. In-situ measurements weretaken with two types of detector and relatedto field observations and sediment propertiesmeasured from sediment samples.

A Scintrex GIS-5 detector measures totalgamma-ray count rates up to 3 MeV. It is ahand-held detector and can therefore easily betransported in otherwise difficult accessible ar-eas. All over Schiermonnikoog 178 measure-ments were taken (Figure 1) and interpretedwith help of recorded terrain characteristics,such as landscape setting (landforms) and es-timated sediment grain size.

204 206 208 210 212 214 216 218 220

km

608

610

612

614

total count rate (cps)

25 - 40 40 - 55 55 - 70 70 - 85 85 - 100N

Figure 1: Total sediment gamma radioactivity atSchiermonnikoog.

Most landforms were significantly differ-ent in their count rates. In general, lowestcount rates were found on the beaches andbeach plains. Intermediate values were foundin most dune belts, at the intertidal flats andat salt-marsh sites with thin clay layers. High-est count rates were found on salt-marsh siteswith thick clay layers, in an older dune beltand a beach site with very local enrichment ofheavy minerals. When variations in water con-tent are accounted for, most variations in countrate can be attributed to variations in sediment

grain-size distributions of the landforms. Onlythe older dune belt may have another set offingerprints (a characteristic activity concen-tration of a sediment fraction) than the restof the island, indicating a different sedimenttransport pattern at the time of its genesis.Sample analyses will be carried out to verifythese results.

Future studies will zoom in at the island’ssalt marsh, and so to study the sediment vari-ability of one of its closest sediment sources,the intertidal flats close to the salt marsh weremapped using the PANDORA detector. Thedata (Figure 2) can be interpreted with thehelp of field observations, while later Monte-Carlo modelling will be used for interpretingvariable measurement conditions (e.g. with orwithout a thin water layer).

2 08 2 10 2 12 2 14 2 16 2 18 2 20

km

6 08

6 10

6 12

6 14

to tal count rate (cps)

150 - 250 250 - 300 300 - 350 350 - 450 450 - 550

NPRELIM INARY

Figure 2: Count rates of sediment gamma radioactiv-ity on the intertidal flats of Schiermonnikoog (prelimi-nary data).

The dominant factor determining varia-tions in radiation appears to be, again, sedi-ment grain size. Count rates were high closeto the tidal divide, where the sediment was no-tably more muddy, and close to the salt marshwhere also more mud is expected. The re-sults point in the direction of there being onlyone set of fingerprints for the sediments, whichwould mean that the sediments on the inter-tidal flats do not show major differences in ori-gin or have experienced sorting processes.

a) Community and Conservation Ecology, Univer-sity of Groningen, The Netherlands.

59

5.11 Variations in gamma radiometry at a layered salt marsh

A.V. de Groot, R.J. de Meijer, J.P. Bakkera)

Coastal salt marshes (Dutch: kwelders)are important as coastal defence and for theirunique ecology. Salt marshes on barrier is-lands, like on Schiermonnikoog (NL), gener-ally consist of a layer of clay on top of sand.As the salt marsh on Schiermonnikoog is ex-panding, sites of various ages, and thereforethickness of the clay (or top) layer, can befound on the island. This way the developmentof the top layer through time can be studied:the rate of increase in the top-layer thickness,but also possible lithological changes. Sedi-ment natural gamma radioactivity depends onsediment properties, in practice meaning thatclay is generally more radioactive than sand.Therefore, radioactivity was mapped in-situ atsalt-marsh sites of various ages. If the top lay-ers at these sites are homogeneous over theirthickness, radioactivity and top-layer thicknesswill be correlated through a simple layer model[1]. If the correlation is poor, the sedimentprobably shows inhomogeneities. Four tran-sects (A to D) on the salt marsh were chosen,extending from the intertidal flats or a creekto the dunes that border the salt marsh, withages of 10, 20, 35 and 110 years old, respec-tively (Figure 1). Every 25 m, or in the caseof transect D every meter, measurements ofradioactivity (total count rates with a Scin-trex GIS-5 detector) and top-layer thickness(with a hand gauge) were taken. For all tran-sects together, the total count rate increasedwith measured top-layer thickness (linear re-gression with R2 = 0.75 and p < .001, Figure2). The relation per transect is negligible atthe youngest transect (A), but increases withage, most probably because the range of clay-thickness values increases with age. The layermodel has been applied to the individual tran-sects as well as to all values together. All tran-sects required different activity concentrationsas input parameters and the resulting fits dif-fered in quality. In the younger transects, themodel did not improve the relation between ra-diometry (in the form of calculated clay thick-

ness instead of total counts) and measured claythickness, and only a marginally better agree-ment was found in transect C. Only in transectD and in all data together the model provideda notable improvement. The data variation isapparently too large for a small range of thick-nesses to show a good relation with radiome-try. Only at older sites the clay layer is thickenough to average out the effect of inhomo-geneities like small included sand layers. Thedifferences in fitting parameters indicate thatchanges in sediment throughout salt-marsh de-velopment are possible. Further research willtherefore look into detail to the clay layers.

20 8 21 0 21 2 21 4 21 6 21 8 22 0

km

60 8

61 0

61 2

61 4

CB A

sa lt marshD

N

Figure 1: Measurement sites. A is 10 years old, B 20;C 35 and D 110 years old.

measured clay thickness (cm)

0 10 20 30 40

Tot

al c

ount

rat

e (c

ps)

40

50

60

70

80

ABCD

Figure 2: Total count rate as function of measuredclay-layer thickness. Different dots refer to the respec-tive transects.

a) Community and Conservation Ecology, Univer-sity of Groningen, the Netherlands.

[1] A.V. de Groot et al., KVI Annual Report, 68(2003).

60

5.12 Initial design of software for a prototype of a radiometric as-phalt layer thickness monitor

E.R. van der Graaf, R.J. de Meijer, R. ten Have, H.J.N.A. Bolka)

The next step in the development of theradiometric method for the on-line determina-tion of thickness of asphalt layers on roads [1,2]is the design and construction of a prototype.This prototype will consist of two gamma-raydetectors, one will be mounted at the back andthe other at the front of an asphalt paver (Fig-ure 1). The front detector will take spectrafrom the underground before the asphalt layeris present, the detector at the back will moni-tor the combination of underground and withasphalt layer. The spectra will be integratedfor every 10 m length of asphalt that is ap-plied. This length is deduced from readings ofan odometer that together with the spectra arestored into a datalogger.

In case of an on-line system these datastreams have to be handled real-time by ded-icated software. In 2004 NGD was commis-sioned by Heijmans to make a framework forthis software. The basic design consists of fourmodules (Figure 2). The spectra measured byboth detectors and the distance informationof the odometer are collected by the datalog-ger module and integrated per 10 m. Thesespectra are stamped with the distance (posi-tion of the paver) and given as input to thespectrum analyzer module. This module willdeconvolute the spectra in standard spectraand calculate apparent radionuclide concentra-tions (40K, 238U, 232Th) in the areas in front(no layer) and at the back (with an asphaltlayer) of the paver. These are used as inputby the next module that calculates the layerthickness by using a simple two-layer model inwhich each layer acts both as source and at-tenuator of radiation. This module also usesinformation on mass attenuation, density andradionuclide concentrations of the material ofthe two layers that has to be available a priorifrom a calibration. The last module uses thelayer thickness per 10 m to alphanumericallydisplay the results on a monitor. This informa-tion can be used by the operator of the paverto adjust the machine such that the specified

thickness is obtained.Two levels in the software are envisaged.

At the operator level the software can only bestarted and then used to monitor layer thick-ness. At specialist level settings of the de-tectors are accesible and also standard spec-tra and other calibration parameters can bechanged.

The next steps foreseen in the prototypedevelopment are the final design (e.g. choice ofdetector material) of the prototype, implemen-tation of a first version of the software to beused with this prototype, test and calibrationof the prototype in a laboratory setup and finaltests and further optimisation in field tests.

Layer thicknessmodule

detector

PM

Elec.

FSA

MCA

Concentration

Spectrum

detector

PM

Elec.

FSA

MCA

Concentration

Spectrum

odometer

datalogger

afstand0 100 200 300 400 500 600 700 800 900 1000

dik

te d

ekla

ag r

adio

met

risc

h (m

m)

10

20

30

40

Layer thicknessmodule

detector

PM

Elec.

FSA

MCA

Concentration

Spectrum

detector

PM

Elec.

FSA

MCA

Concentration

Spectrum

odometer

datalogger

afstand0 100 200 300 400 500 600 700 800 900 1000

dik

te d

ekla

ag r

adio

met

risc

h (m

m)

10

20

30

40

Figure 1: Scheme of prototype layer thickness moni-tor. The dotted octogonal is the domain for which soft-ware has to be designed.

spectrum

spectrum

distance

DATALOGGERSPECTRUM ANALYSIZER

LAYER THICKNESSCALCULATION

READ OUTMONITOR

spectra per 10 m concentrations per 10 m thickness per 10 m

standardspectra

calibration input

spectrum

spectrum

distance

DATALOGGERSPECTRUM ANALYSIZER

LAYER THICKNESSCALCULATION

READ OUTMONITOR

spectra per 10 m concentrations per 10 m thickness per 10 m

standardspectra

calibration input

Figure 2: Flow of information between the four soft-ware modules

a) Heijmans Infrastructuur en Milieu B.V., Ros-malen, The Netherlands.

[1] E.R. van der Graaf et al., KVI Annual Report,66 (2003).

[2] E.R. van der Graaf et al., KVI Annual Report,67 (2003).

61

5.13 ERRICCA 2, A European radon forum

E.R. van der Graaf

The European Radon Research andIndustry Collaboration Concerted Action(ERRICCA 2) was a three year project thatstarted in 2002 and closed at the end of 2004.The project was funded by the European Com-mission. ERRICCA 2 comprised a total of 35organisations (both from science and industry)representing 20 countries and was co-ordinatedby the UK’s Building Research Establishment.The project was the successor of ERRICCA(European Research into Radon in Construc-tion Concerted Action) that only included sci-entific institutes. NGD participated in bothERRICCA projects. The task of ERRICCA2 was to establish a European scientific ledindustrial forum aimed at reducing risks tohealth from radiation (with the emphasis onradon) in the built environment. The forumconvened five times during the three year pe-riod. ERRICCA 2 considered the followingfive topics and tasks: 1) The establishment ofa European radon website; 2) Increase publicawareness; 3) Protection of new buildings; 4)Remediation measures for existing buildings;5) Common measurement protocols.

NGD has mainly contributed to the firstthree topics. A framework of the website(www.european radon.ntua.gr) has been set upand was during the project loaded with con-tent. The website will be finalized in 2005 withthe upload of all the ERRICCA 2 final reports.NGD has supplied information to this websiteand is responsible for the link to the Dutchinformation. The main instrument to increasepublic awareness were the national forums thatwere organised every year in each of the par-ticipating countries. NGD was responsible forthe Dutch forums where subjects like the Ra-diation Performance Index and radon as a toolfor the non-destructive evaluation of concretewere discussed. NGD was co-topic leader ofthe third topic ‘protection of new buildings’.More specifically two deliverables were dealtwith namely:

• Identification and evaluation of designtools such as pre-construction soil mea-

surements of use in the planning stage ofradon protection of new buildings;

• Identification and evaluation of post-construction measurement proceduresneeded to assess the effectiveness ofradon protective measures or other as-pects of the system.

NGD compiled a report [1] on these deliv-erables on basis of a search of the litera-ture and using two questionnaires distributedamongst the ERRICCA 2 participants. It wasconcluded that at this moment there are notechniques to reliably decide which counter-measure would be best suited for a certaindwelling. To mediate this situation, furtherdetailed research is needed on the parame-ters determining the magnitude of radon entryfrom/through both soil and building materi-als in various dwelling types. Such researchhas been undertaken earlier for small test sitesor real dwellings. In all these studies, how-ever, well controlled and systematic experi-ments were not possible due to lack of controlof meteorological conditions and inflexibilityof the structures. Also all these experimentshave been relatively small scale because of bud-get constraints. To make further progress inthe optimisation of radon mitigation it is rec-ommended to conduct systematic research onflexible test houses in a large (indoor) facility.Deeper understanding of radon mitigation willalso help in drafting guidance on detailing theradon countermeasures. It is advised to have acentral European radon test site with fully in-strumented test dwellings that are representa-tive for some typical building styles of variouspart of Europe. This radon test site should actas a user facility to which researchers can ob-tain access by submitting research proposals.This large radon research facility should be es-tablished as the European expertise centre onradon.

[1] E.R. van der Graaf, KVI Internal Report, R125(2004).

62

5.14 Monte Carlo determination of electron-photon conversion effi-ciency in laser experiments

M. Maucec, J. Galya), T. Zagara)

As the power of lasers continues to increase,a new area of laser induced nuclear reactionsis emerging. Photo-reactions, for example, areof interest for alternative transmutation pathstudies. The photo-reactions by means of highintensity lasers follow a three cascade scheme:

• Generation of MeV electrons with a high-intensity laser plasma

• Bremsstrahlung conversion of MeV elec-tron into MeV photons in a high Z solidtarget

• Nuclear reactions induced by the Brems-strahlung high-energy photons

0 1 2 3 4 5 6 7 8 9 100

1

2

3

4

5

6

7

8

Co

nve

rsio

n e

ffic

ien

cy

Thickness (mm)

Energy (MeV): 1 10 20 100 5 15 50 150

Figure 1: Electron-photon conversion efficiencycurves, calculated by MCNPX for the Ta target withvarying thickness and a set of incident electron ener-gies.

The conversion efficiency between electronsand bremsstrahlung photons depends on theelectron energy, the converter material andconverter thickness. Due to the strong energydependence of the conversion, the target mustconsist of a high Z material. To determine ifan optimum converter thickness exists, fromwhich the bremsstrahlung efficiency reachesthe maximum, a set of Monte Carlo simula-tions has been carried out using the code MC-NPX. A mono-energetic beam of electrons with

energies ranging from 1 to 150 MeV was mod-elled, impinging on a standard tantalum (Ta;density = 16.65 g/cm3) target, with squarecross-section area of 3x3 cm2 and the thick-ness varying from 0.5 mm to 10 mm. Theconversion efficiency (ε) is often referred toas “fraction of kinetic energy of the incidentelectrons that emerges in the form of Brem-strahlung from a target of thickness d”.

In the simulations it was defined as

ε = Φoutp /Φin

e (1)

where Φoutp represents the photon flux

(cm−2 s−1) through the back surface of the Taconverter and Φin

e represents an incoming elec-tron flux through the front surface. The cal-culated conversion efficiency curves, given inFigure 1 indicate that the optimum converterthickness corresponds approximately to half ofthe electron range. The statistical uncertaintyassociated with the integral values of the pho-ton and electron flux were both below 0.5%,therefore the uncertainty of the estimated effi-ciency remains within 1%.

The performances of the photon-inducedtransmutations are essentially limited by theabsorption phenomena in the “thick” targetof materials to transmute. Further MCNPXcalculations are planned to determine the op-timum electron spectrum-converter setup tooverlap the giant dipole resonance of thephoto-reaction cross section, to assess pair-production and loss of photons in photo-reaction experiments and to determine the rateof photo-fission and neutron activation reac-tions in the 238U target, associated to the Taconverter.

a) European Commission, JRC Institute forTransuranic elements (ITU), Karlsruhe, Ger-many.

63

64

Chapter 6

Miscellaneous

65

6.1 RIASH: Radioactive Ions and Atoms in Superfluid Helium

P. Dendooven, S. Purushothaman, K. Gloos, J. Aystoa), J. Huikaria), W.X. Huangb), N. Takahashi c)

In the RIASH project [1], several issues re-lated to radioactive ions and atoms in super-fluid helium will be investigated. In 2004, wepurchased a cryostat and related equipmentand concentrated on the design and construc-tion of an experimental cell to continue thestudy of the use of superfluid helium to stophigh-energy radioactive ions and extract themas a low-energy ion beam.

The cryostat was designed in collaborationwith and manufactured by Vacuum SpecialsB.V. [2] to reach temperatures close to 1 K at aliquid helium consumption of 6 liter/day. Thecryostat was fitted with temperature sensorsand coaxial and twisted-pair copper wiring.During commissioning, a temperature of 1.0 Kand a helium consumption of 9 liter/day wasreached. Although the cryostat is thus suit-able for the planned experiments, we will im-plement some modifications in order to reducethe helium consumption.

During the SNOWBALL project inJyvaskyla in 2001-2002, alpha decay recoilions from a 223Ra source were transported ina closed cell from inside liquid helium at thebottom, across the liquid surface, through thevapour region to the top of the cell [3]. Thecollection of ions on a thin aluminum collectorfoil was measured via their alpha decay using asilicon surface barrier detector. In that work,the dependency of the efficiency on the tem-perature and electric field in the liquid regionwas investigated. Based on those results andaiming to substantially increase the transportefficiency from the 0.07 % obtained in [3], anew experimental cell for use with alpha decayrecoil ions was designed (Figure 1). The maindesign criterion for the electrode structure wasmaximization of the electric field throughoutthe liquid helium volume. The present de-sign allows an electric field from 500 V/cm atthe source to 700 V/cm at the liquid surface.

The cell was constructed at the Department ofPhysics of the University of Jyvaskyla.

5 cm43210

Source

Bottom electrode

Guidingelectrodes

Focusingelectrode

Collector foil

Detector holder

Figure 1: Electrode design and equipotential lines ascalculated by the SIMION ion optics simulation soft-ware. Alpha decay recoil ion trajectories from thesource through the focusing electrode to the collectionfoil in front of the alpha detector are shown. The volt-ages on the electrodes are indicated.

a) Department of Physics, University ofJyvaskyla, Finland

b) Institute of Modern Physics, The ChineseAcademy of Sciences, Lanzhou, China

c) Osaka Gakuin University, Japan[1] www.kvi.nl/ dendooven/RIASH/index.html[2] Vacuum Specials BV., Rosmolenlaan 1, 3447

GL Woerden, The Netherlands[3] W.X. Huang et al., Europhys. Lett. 63, 687

(2003).

66

6.2 Meeting report: Fundamental Interactions

K. Jungmann, R. G. E. Timmermans, Ch. Weinheimer a)

Despite the astounding success of the Stan-dard Model (SM) of the strong and electroweakforces, the existence of new fundamental in-teractions is expected, for compelling theoret-ical reasons and because of the neutrino oscil-lations discovered in recent years. New experi-mental clues are urgently needed to distinguishamong the many proposed speculative SM ex-tensions. Some intriguing questions that facethe field in the near future are the following:

• The neutrino mixing parameters must bedetermined and precise measurements ofthe absolute masses are needed. Dou-ble β-decay (0νββ) experiments shouldbe pursued to establish whether neutri-nos are Dirac or Majorana particles.

• Searches for electric dipole moments(EDMs) in different systems (neu-tron, nuclei, atoms, molecules) havea very high potential to discover newsources of CP violation, as required bybaryo/leptogenesis models.

• Processes that violate baryon or leptonnumber or lepton flavor are extremelywell suited to constrain speculative SMextensions.

• Correlation measurements in β-decaycan reveal non-(V − A) contributions toweak processes.

• Parity nonconservation in atoms and inelectron-nucleon scattering.

• Speculations about violation of CPT andLorentz invariance.

• Possible time dependence of fundamental“constants”.

An international workshop was held at theECT*, Trento, Italy, from June 21-25, 2004.Ongoing efforts that address the above ques-tions, both theoretically and experimentally,were highlighted and discussed in depth. The

workshop was concluded with a discussion toidentify urgent future work.

Several experiments that need input fromtheory were identified: (i) The new-physics po-tential of atomic parity violation experimentsneeds to be establised. The reliability of thenecessary atomic theory must be improved.(ii) The calculation of the Schiff moments ofdeformed nuclei needs a firmer microscopic ba-sis. (iii) The relation between forward nuclearscattering and time-reversal violation must befirmed up. (iv) New microscopic approachesto the nuclear matrix elements for 0νββ ex-periments are urgently needed. (v) The incon-sistency in (g − 2)hadr from e+e− and τ -decaydata needs to be resolved; the hadronic light-by-light evaluation must be improved. (vi)Which quantities are relevant to compare intesting CPT invariance?

Similarly, theoretical activities that needexperimental input were found: (i) The Diracor Majorana nature of neutrinos must be set-tled. The Heidelberg-Moscow 0νββ experi-ment suggests Majorana neutrinos; indepen-dent confirmation is badly needed. (ii) Directneutrino-mass measurements (specifically KA-TRIN) are imperative to fully understand neu-trinos. (iii) Leptonic CP violation should belooked for. More precise neutrino oscillationexperiments are needed. This research couldbenefit from a multi-MW proton accelerator(like many others, such as searches for rare de-cays). (iv) Experiments to measure the atomicEDM of radium are underway. (v) A new tech-nique to measure the EDMs of charged parti-cles in a magnetic storage ring has been pro-posed. The deuteron and the muon will beprobed first. (vi) There are hints from cosmol-ogy for a time variation of the fine structureconstant α, which needs confirmation. Theimplications for other fundamental constantsneeds to be studied. (vii) Additional exper-imental input to (g − 2)hadr is expected (e.g.KLOE).

a) University of Munster, Germany.

67

6.3 Status of HISPARC Groningen

J.G. Messchendorp, J. Bouwa), H. Goedegebureb), P. Koopmansc), T. Koopsb), B. Kruijver, J. Massolt

The goal of the project “Cosmic Radiation”is to promote the subject of physics at highschools in Groningen. In this project, studentsand teachers of high schools in and aroundGroningen are invited to participate in a large-scale experiment at which high-energetic cos-mic rays are being studied. Such an outreachprogram gives students, and also teachers, theopportunity to learn - in an exciting way -about experimental techniques which are usedin modern nuclear and particle physics.

The experiment aims to study particlesfrom different sources in the Universe and withenergies up to 1020 eV. These particles pene-trate the atmosphere of the earth after whichthey react instantaneously with oxygen and ni-trogen atoms. A variety of new elementaryparticles is produced which subsequently de-cay or collide with other molecules in the at-mosphere. The resulting shower of particlescan stretch over long distances, depending onthe energy of the incident cosmic radiation. Bymeasuring at sea level the density of the sec-ondary particles, one is able to reconstruct theenergy and angle of the primary cosmic ray.

Figure 1: High-school students from the Praediniusassembling a scintillation detector for their school.

To measure the density distribution of thecosmic shower, several high schools in Gronin-gen will be equipped with a detection systemconsisting of two plastic scintillator counters.Such detectors are in particular suited to regis-ter electrons and muons, which form the dom-inant part of the shower. The acquired data

of each detector station are collected by a cen-tral server using the internet. Furthermore,each event will be labeled with a time stampobtained via a GPS receiver. With this infor-mation, correlations between different stationsare studied and a density profile of the cosmicshower can be obtained.

At present, four high schools in and aroundGroningen (Maartenscollege, Praedinius Gym-nasium, RSG de Borgen, and Wessel GansfortCollege) are participating or have indicatedto join the project in the very near future.The first group of high-school students fromthe Praedinius have successfully tested and in-stalled a complete detector station on the roofof their school as illustrated in Figures 1 and 2.Two more stations are presently being assem-bled and tested at KVI by high-school studentsfrom the Maartenscollege and Wessel GansfortCollege. The installation of these detectors arescheduled for 2005.

Figure 2: The first operational detector station at thePraedinius school in Groningen.

The high-school project “Cosmic Radia-tion” is part of the national program “HIS-PARC” (HIgh-School Project on AstrophysicsResearch with Cosmics) which is coordinatedby NIKHEF in Amsterdam. HISPARC was in2004 awarded with 1 MEuros by the AltranFoundation for Innovation.

a) Maartenscollege, Haren.b) Wessel Gansfort College, Groningen.c) Praedinius Gymnasium, Groningen.

68

6.4 Neutrino physics: a new research line for KVI

A.M. van den Berg, J.C.S. Bacelar, E. van der Graaf, K.P. Jungmann, N. Kalantar-Nayestanaki,H. Lohner, R.J. de Meijer, J.G. Messchendorp, O. Scholten, R.G.E. Timmermans, H.J. Wortche

In 2004 we have explored new research linesin the field of neutrino physics. Our strategyhas been to define new experiments, as well asto explore options to join existing collabora-tions. Briefly, we present here these researchlines; for some of them more details can befound at other places in this report.

KATRIN

Starting at the lowest energy, we are investi-gating to join the KATRIN (KArlsruhe TRI-tium Neutrino) experiment, which aims to de-termine the mass of the electron neutrino withthe unprecedented sensitivity of 0.2 eV, whichis an order of magnitude more accurate thanany other experiment. KVI has been invitedby the KATRIN collaboration to design, toconstruct and to take on the responsibility foran electron gun placed upstream of the tritiumsource. This crucial part of the KATRIN setup will be used to monitor energy losses of theelectrons from the tritium source and to al-low for an accurate calibration of the electronspectrum.

EARTH

At a somewhat higher energy the EARTH pro-gram has defined as its first stage the devel-opment of direction-sensitive antineutrino de-tectors, specifically aiming for the detection ofgeo-antineutrinos. The detection of such neu-trinos will reveal the location of heat sourcesinside the Earth if they are driven by decayfrom primordial thorium or uranium. The fullversion of a first antenna is expected to be de-ployed at the Caribbean island Curacao. Itstotal sensitive volume is expected to be 4 kton(about three times the volume of the Kam-LAND neutrino detector in Japan). The initialphase of this KVI initiative is partly fundedby ASTRON in Dwingeloo (NL). Furthermore,the direction sensitivity can be used to moni-tor human activities related to nuclear fission

processes, such as nuclear explosives and powerplants.

ANTARES and KM3NeT

We will join the ANTARES experiment,which is the precursor of KM3NeT. OtherDutch participants of these projects are fromNIKHEF and the universities of Amsterdamand Utrecht. The KM3NeT is a neutrinotelescope which will deployed in the Mediter-ranean Sea by a European collaboration. Thepurpose of ANTARES (as well as NESTORand NEMO) is to demonstrate the proper func-tioning of a deep-sea telescope with a volumeof 0.05 km3. These deep-sea detectors are be-ing built to search and identify point sourcesin the cosmos and to measure the spectrumof high-energy neutrinos. The KM3NeT ini-tiative was launched in 2003 with the aim tobuild a large neutrino telescope with a volumeof at least 1 km3. A study has been approvedfor funding by the EU leading to a completedesign in 2009.

LOFAR and ZESANA

We are joining the initiative of the Dutch as-tronomers to use LOFAR for the detectionof high-energy cosmic rays. The radio tele-scope LOFAR is presently under constructionand will be deployed in the northern part ofthe Netherlands in the coming 2 years usinga Dutch investment of 52 MEuro. It will bethe largest radio telescope in the world, andits prototype LOPES has demonstrated that itwill be very well suited to use it as a cosmic-raytelescope as well. The aim of these studies willbe similar to ANTARES and KM3NeT; i.e. topin-point possible point sources in the cosmosand to hunt for cosmic rays at extremely highenergies, beyond the GZK limit. Along a sim-ilar line we are opting to extent LOFAR witha telescope suitable for the detection of neu-trinos at the highest energies: the ZEchsteinSAlt Neutrino Array (ZESANA).

69

6.5 ZESANA: The ZEchstein SAlt Neutrino Array

A.M. van den Berg, J.N. Breunesea), J.H. Brouwera), M. Chibab), T. Kamijob), H.F. Mijnlieff a), O.Scholten

We report here on the initial measurementsperformed in the framework of the ZESANAproject. This project aims to develop an ultra-high energy neutrino detector in one of the saltdomes in the northern part of the Netherlands.High-energy cosmic neutrinos, with an energyof at least 1015 eV, are predicted on basis ofmeasured energies of cosmic rays impinging onthe Earth from outer space. The sources forthe very high-energy neutrinos (and for thatmatter the cosmic rays) remain an open ques-tion.

Figure 1: The Zechstein salt layers in the undergroundof the Netherlands. The dark spots indicate locationsof salt domes ( c©TNO-NITG Utrecht).

The detection of extremely high-energyneutrinos is scientifically one of the most de-manding questions in the field of astroparticlephysics [1]. The APS Neutrino Astrophysicsand Cosmology Working Group puts specialemphasis on the following primary questions:1) What is the role of neutrinos in shapingthe universe? 2) Are neutrinos the key to theunderstanding of the matter-antimatter asym-metry of the universe? 3) What can neutri-

nos disclose about the deep interiors of as-trophysical objects, and about the mysterioussources of very high energy cosmic rays? Thereport from this Working Group strongly rec-ommends the development of the next gen-eration of neutrino telescopes, based on ra-dio Cherenkov techniques as introduced byAskaryan [2] and recently initiated by Gorhamet al. [3] in the USA. The innovative approachsuggested by Askaryan exploits the fact thatduring the transition of a high-energy neutrinothrough a solid, coherent Cherenkov radiationis emitted with most of its power in the ra-dio band. Of course to detect these (rela-tively) weak radio signals, a radio-transparentmedium is needed; rock salt is one of the ma-terials with the longest attenuation length forradio signals and therefore salt domes with avolume of several km3 can perfectly act as hugehigh-energy neutrino detectors. As the under-ground of a large part of the Netherlands haslarge quantities of rock salt from the Zechsteinperiod and because several salt domes have arelatively small overburden, it became of inter-est to test the salt properties from one of thedomes in the province of Groningen.

In the fall of 2004 rock salt samples fromthe Zuidwending salt dome obtained fromTNO-NITG in Utrecht have been analyzed atTMU with the cavity perturbation method. Ata frequency of 1 GHz the measured attenua-tion length was 78 ± 11 m. Measurements at0.3 GHz, where longer attenuation lengths areexpected, are still ongoing.

a) TNO-NITG, Utrecht, NL-3584 CB Utrecht,The Netherlands.

b) Tokyo Metropolitan University, Tokyo, Japan.[1] http://149.28.120.22/neutrino/.[2] G. Askaryan, JETP 14, (1962) 441 and JETP

21 (1965) 658.[3] P.W. Gorham et al, astro-ph/0412128 and ref-

erences therein.

70

Chapter 7

Agor, Ion Sources and Radiation Safety

71

7.1 Survey of beam time used for experiments with AGOR in 2004

A.M. van den Berg

In 2004, a substantial fraction of the avail-able beam time was used for the commission-ing of new pieces of equipment in the experi-mental area. These are the magnetic separatorfor the TRIµP set up and the BINA, whichreplaces the SALAD set up. Prior to thesecommissioning experiments, substantial downtime was scheduled to allow for the installa-tion of this separator in the newly-constructedexperimental area: the T-cell. Parallel to thiswork in the T-cell, major maintenance on thecyclotron itself has been carried out.

In particular for the commissioning of theseparator, new beams have been developedsuch as 206,207,208Pb and 133Xe at about 8AMeV. Both the ‘fusion’ mode and the ‘fragmen-tation’ mode of the separator have been com-missioned. The first experiment, initiated byNaviliat-Cuncic, with the separator has beenperformed in the last months of the scheduledperiod.

The beam time available for PAC-approved

experiments was somewhat low this year, be-cause of scheduled stops in the course of theyear and because of problems with equipment.Both AGOR and the focal-plane detector ofthe BBS were hampered in their operationsdue to hardware failures. For AGOR, the ma-jor setback has been a shorting problem withinthe new EMC1 channel, which had to be re-moved in the second half of the year. At aboutthe same time, 2 wire chambers from the focal-plane polarimeter of the BBS broke down be-cause of shortage in their wire planes. Thesedetectors had to be shipped for repair to Tri-umf.

Successful experiments were performed atthe BBS (S46 and S47) and at the multi-user beam line (T15, T16, and T18). Fur-thermore, beam time was given to Onderwa-ter and Stephenson to perform initial measure-ments for a deuteron polarimeter needed bythe deuteron EDM collaboration.

PAC Title Spokesperson shifts shifts AGOR beam# by PAC used

S46 The (α,2He) reaction: an alternative Wortche 18 18 40A, 67A, 90A MeV α2He production channel for spin-correlationstudies

S47 Structure of electric dipole strength below the Zilges 26 30 34A MeV αparticle threshold

T15 Tests of a scintillation GEM dosimeter Schippers 12 25 150 MeV pKreuger

T16 Radiation damage to parallel organized organs Meertens 27 11 150 MeV pafter high-precision irradiation

T18 Scintillation crystal development: irradiation Lewandowski 24 1 90A MeV 2H+

and response to hadrons Novotny

2004: Total shifts for PAC experiments 85Grand total shifts for PAC experiments 1662(AGOR schedule started November 1996)

Director’s timeCommissioning of the TRIµP separator Berg 64 various heavy ion beamsCommissioning of BINA Kalantar 11 170, 190 MeV pMeasurement of deuteron analyzing powers Onderwater 12 40A, 55A MeV d

StephensonPrecision measurement of the 21Na decay Naviliat-Cuncic 12 43A 21NeTotal director’s time 99

Table 1: Beam time for experiments with AGOR in 2004.

72

7.2 AGOR status report

S. Brandenburg, W.K. van Asselt, M.A. Hofstee, A. Kroon, H. Post

In 2004 the AGOR-facility has operateda total of 23 weeks starting in beginning ofMay. In the second half of the year severalexperiments had to be cancelled due to prob-lems with the experimental setup, which hasreduced the delivered beamtime significantly.The availability of the cyclotron during therunning period was 80 %. The schedulingstatistics is summarized in table 1.

Table 1: Machine-time usage in hours

2003 2004Beam delivered 2096 1473Machine tuning 281 323Machine studies 191 333Non-scheduled standby 264 127Scheduled maintenance 1191 1148Non-scheduled maintenance 345 566Scheduled standby 4392 4790Total 8760 8760

Half of the non-scheduled maintenance wasdue to the new extraction channel EMC1.

During the shutdown period the installa-tion of the TRIµP-fragment separator was themost important activity. The commission-ing of the new extraction channel EMC1 andsome machine studies were performed in par-allel with this installation.

EMC1The original EMC1 extraction channel limitsthe K-value of the cyclotron to about 450 be-cause it is pinched between the magnet polesat field above 3.5 T. The origin of this problemis twofold:• The compression of the poles is larger than

calculated: at 4 T it has been measured tobe almost 1 mm instead of the predicted0.5 mm.

• The EMC1 extraction channel is 0.5 mmhigher than designed. This is caused byadditional insulation around the windings,added during the initial commissioning toremedy ground faults.Heavy ion experiments, such as planned

in the framework of the TRIµP-programme,would be seriously hampered by this limita-

tion: to produce the beams requested a highercharge state is needed, thus leading to a lowerintensity. Therefore a new channel has beenconstructed.

During the shutdown period the new chan-nel has been successfully commissioned: thechannel has been operated at the 4.1 T max-imum field and the operation parameters arenearly identical to those of the old channel. Af-ter several months of operation the new chan-nel developed ground faults in the bias and gra-dient windings, which are only present whenthe channel is powered in a magnetic field be-yond 3 T. After extensive diagnostic measure-ments to localize the faults the channel wasreplaced by the old one and completely dis-assembled. No traces of the earth faults werefound. The channel is currently being reassem-bled with additional insulation material butwithout increasing its height.

Beam developmentWith the completion of the TRImP-separatorthe change in emphasis from light ion beamsto heavy ion beams has started. Beams of 12C,14N, 16O, 20,21Ne, 24Mg, 131Xe and 206,207,208Pbat energies between 8 and 20 MeV per nucleonwere developed and used for the commission-ing of the TRIµP-separator and initial experi-ments.

The lower limit for α-beams was studiedin reponse to a request to deliver a 120 MeVα-beam for an experiment. According to theoperating diagram the minimum energy is 36MeV per nucleon. At 30 MeV per nucleon itwas impossible to accelerate the beam up toextraction radius, the beam was lost at the lo-cation of the νr + 2νz = 3 coupling resonance.At 32 MeV per nucleon the beam arrived atextraction radius but the extraction efficiencywas prohibitively low, again related to crossingof the coupling resonance. At 34 MeV per nu-cleon the beam an extraction efficiency of 30%, low in comparison to most beams but ac-ceptable in view of the nA intensity requested,was achieved although the beam still crossesthe coupling resonance.

73

7.3 Status of the KVI ion sources

I. Formanoy, H.R. Kremers, J. Mulder, J.P.M. Beijers

At KVI three ion sources are used to injections into AGOR, i.e. a cusp source for protons,deuterons and α-particles, an ECR source(ECRIS 3) for multiply-charged ions and asource for polarized protons and deuterons(POLIS). A second ECR source (ECRIS 4)feeds a dedicated beam line for atomic physicsexperiments. In 2004 POLIS has only beenused to produce polarized deuterons for oneexperiment. Since the addition of a Lamb-shift polarimeter its figure-of-merit has signif-icantly increased, mainly because it is mucheasier to tune the source for maximum polar-ization. Also ECRIS 4 got little attention.This source has been running very smoothlyand is in constant use. The cooling machine forthe hexapole has been replaced because the oldone broke down. Only the gaseous ions He2+,O6+ and Xe18,26+ have been produced.

Most of the work was done on ECRIS 3 anddesign work for the new ECRIS upgrade (seenext contribution). A small leak in the plasmachamber caused by the injection of too much rfpower had to be repaired. Low-charge beams(q = 3, 4) of C, N and O have been producedfor design studies of a thermal ionizer neededin future TRIµP experiments.

0 1 2 3 4 5 6 7 8 9 10Ion charge

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Cur

rent

(eA

)

Poven=6.2 WPoven=4.8 W

Figure 1: Charge-state distributions of 25Mg.

A new F7+-beam has been developed by sim-ply injecting CF4 gas into the plasma chamber.The production of metal-ion beams, mainly forTRIµP, took again much effort. In addition toMg- and Pb-beams a new Na7+ beam has beendeveloped. Typical charge-state distributionsof the Mg- and Pb-beams are shown in Fig-ures 1 and 2, respectively. All these beamshave been produced with the large GSI-typeoven. In order to obtain stable Na- and Mg-beams with a low material consumption a thintantalum heat shield has been inserted into theplasma chamber. We noticed with Pb- andMg-evaporation that after prolonged use theextracted beam decreased. From inspectionof the oven it appeared that there was stillenough material present in the crucible, butthat the oven opening was partly silted up withsolid material. Off-line measurements with athermocouple of the axial temperature distri-bution in the oven showed that the tempera-ture at the oven opening was ≈ 100 C lowerthan at the oven back end. We will try to solvethis problem by additional heating and/or bet-ter heat isolation of the front end of the oven.

24 26 28 30 32 34Ion charge

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

Cur

rent

(eA

)

Poven=12.6 W,PRF=520 WPoven=7.4 W,PRF=450 W

Figure 2: Charge-state distributions of 208Pb.

74

7.4 The new ECRIS upgrade

H.R. Kremers, I. Formanoy, J. Sijbring, J.P.M. Beijers

A significant increase in extracted beam in-tensities of multiply-charged ions from the in-jector ECRIS is required in order to fulfill fu-ture TRIµP requirements. As a first step tomeet these requirements we will remodel thepresent CAPRICE-type ECRIS according tothe so-called AECR-ECRIS of the universityof Jyvaskyla, which was originally designedby the ECRIS group of LBNL-Berkeley [1].Important features of this design are an alu-minum plasma chamber which houses six per-manent magnet NdFeB bars constituting thehexapole, axial off-axis injection of the rf heat-ing power via a rectangular waveguide andstandard use of a moveable biased disk at theinjection side. Better plasma confinement canbe expected because the new plasma chamberhas a much larger volume (1414 cm3) com-pared to the CAPRICE source (728 cm3). Theplasma chamber has radial access through rect-angular ports between the hexapole bars. Thisenables direct pumping of the plasma chamberwith a 500 l/s turbomolecular pump. Addi-tional pumping on the injection and extrac-tion sides is done by a 170 l/s and another500 l/s turbomolecular pump, respectively, re-sulting in a much better vacuum than in thepresent source. All other subsystems of theCAPRICE source will be reused, including thetwo solenoids with their 1000 A power supplies,the 2 kW 14 GHz microwave generator and the

extraction chamber with electrostatic extrac-tion electrodes.

The new plasma chamber has been builtby the university of Jyvaskyla. After arrivalat KVI the six hexapole bars have been putinto stainless steel cans and inserted in the cor-responding holes of the plasma chamber. Allother necessary components have been man-ufactured by the mechanical workshop. Thenew source is ready for assembly, which willtake place between April and September 2005.A cross section of the new ECRIS is shown inFigure 1.

Figure 1: Cross section of the KVI-AECR source.

[1] Z.Q. Xie and C.M. Lyneis, Rev. Sci. Instrum.65, 2947 (1994).

75

7.5 Revision of the AGOR Main Magnet Power Supplies

M. Stokroos, S. Brandenburg

Under certain, not well-understood con-ditions the 900 Ampere part of the dual10V/900A, 15V/1800A power supply for thesuperconducting coils of the AGOR cyclotronoscillated intermittently. This oscillationcaused very high ripple currents in the capac-itor bank and at a few occasions a commuta-tion failure in the thyristor rectifier, resultingin destruction of a thyristor.

In order to solve this problem the voltageregulation loop and the thyristor firing havebeen re-designed. In the original design thevoltage feedback was taken at the output of thefilter, which leads to a low cut-off frequency forthe regulation. Consequently the gain at themains frequency was insufficient to correct un-balance between the six thyristors.

In Figure 1 the new regulation scheme forthe 900A power supply to improve the stabil-ity is displayed. The rectifier may operate overquadrants I and II, in the latter returning theenergy from the magnet back to the source.The output voltage of the rectifier is negativefor thyristor firing angles ≥ 90 if a current inthe inductive load exists.

In the regulation scheme, the mean value ofthe voltage at the rectifier output is comparedwith the reference level from the current loopoutput. The rectifier output voltage is madeup of several parts of different sine waves andis, with exception of near maximum and mini-mum voltage operation, a saw-tooth like wave-form. In case of a short mains disturbance ora phase unbalance, the integrating voltage am-plifier will assure that the average DC-outputvoltage is maintained by adjusting the firing

angle of the next thyristor. Hence, correctionoccurs in the shortest possible time (300 Hz fora 6-pulse rectifier) and the system stability ismaximised [1].

Once the current in the superconductingcoils has reached its setpoint the current regu-lation maintains the output voltage of the sup-ply at the value needed to compensate the cir-cuit losses. In the new design the LC-filter isno longer within the voltage loop, the DC volt-age drop over the coil L thus has to be com-pensated by the current loop. This introducesa static error at the output of the current inte-grator, which for the maximum current is closeto the supply voltage of the operation ampli-fier used here. To compensate the voltage dropover the cables and current leads a correctionsignal derived from the current readout is in-jected into the voltage regulation loop. Thiscompensation is not perfect as the two powersupplies share a current lead and return cable.Consequently the voltage drop for one powersupply depends on the current of the other.

The current balancing between the rectifierphases was improved by replacing the originalthyristor firing circuit for a commercial one [2]with a better mains synchronization. This alsoreduces the output voltage ripple. Once longterm operation of the 900 A power supply hasdemonstrated the reliability of the new systemthe 1800 A power supply will be modified.

[1] Fk. Bordry et al., CERN-LEP-PC/88-40, July1988.

[2] Enerpro FCOG630D, 6-SCR general purposegate firing board.

Figure 1: Proposed regulation scheme of the 900A power supply.

76

Chapter 8

Technical support

77

8.1 Activities of the Electronics & Electrotechnical Department

M.O. Bleeker, M. Bruining, D. Damstra, H.A.P. van der Duin, A. Felzel, M. Hevinga, H. Kooi, G.van der Kruk, T.W. Nijboer, T.P. Poelman, F. Rengers, J.G. Siebring, M. Stokroos, B.D. Taenzer,R. Terol, R. Tjoelker, J. Vorenholt, P. Wieringa, R. van Wooning

AGOR support Additional work hasbeen done to turn the beam phase measure-ment set up into a more practical system. Anew filter was designed and a new networkanalyser was purchased to improve measure-ment speed and accuracy. The development ofthe new and improved 64-channel beam profilemonitor electronics has been finished. A totalof 50 modules have been produced and will beinstalled in a medical set up for proton therapyin Germany in 2005.

TRIµP support The firmware for thehigh frequency oscillator of the TRIµPquadrupole cooler has been finished and tested.Furthermore, a stepping-motor driven variablecapacitor has been added to the resonancetank of the oscillator to allow for the remotechange of the operating frequency. A highprecision 4-channel Hall probe readout for theTRIµP separator magnets has been designedand built. The electronics rack is equippedwith four current sources and a Keithley high-resolution digital voltmeter with an input mul-tiplexer carefully selected for ultra-low contactpotential.

PLC support Seven PLC pump controlunits for vacuum control of the TRIµP beamline have been built and twelve PLCs havebeen built into the load-sharing units. Theswitchover from Sattcontrol to ABB KT98with the local SCADA system for the control ofthe AGOR helium compressors has been com-pleted this year. PLC control of the beam stophas been replaced and expanded. Tasks like re-

verse osmosis control and fault signalling havebeen moved from the Staefa Control System toother systems.

Electrotechnical support This yearelectrotechnical work was dominated by theconstruction of the TRIµP beam line. twelvepower supplies were made suitable for tripleload sharing and the mains infrastructure forthe TRIµP beam line and lighting for the newexperimental cells were installed.

NGD support A detector data collection,transport and interface system has been de-signed for the NuPulse project. The systemconsists of two units, one is housed within theprobe casing and the other provides the inter-face with a personal computer (see figure 1).Both units are connected to each other via acable with a maximum length of one kilome-tre for transport of data and power. Currentlyfour of these systems have been built for theNuPulse consortium.

Department infrastructure The de-partment has been expanded with three newrooms. Old tables and desks have been re-placed by antistatic workstations complyingwith modern standards of working. Theschematics and circuit board design softwareAccel EDA has been upgraded to PCAD 2004.

Figure 1: The NuPulse measurement and control sys-tem.

78

8.2 Activities of the mechanical department

R. Bergsma, S.J.N. Duinisveld, L. Slatius, H.A.J. Smit Mechanical workshop: H. Dost, R.J. Dussel,E. Latumalea, W.W.P. Olthuis, G.J. Sa, D.J.M Tilman, I. Smid, J. Smid

In 2004 we started the design of a setup forthe mounting of an Inner Shell constructioninside the Plastic Ball. This Inner Shell is ashell of detectors, situated between the vacuumchamber and the inner side of the Plastic Ball.In 2005 this new Plastic Ball setup, togetherwith a new Liquid He-target, will be placed atthe pivot point of the Big Bite Spectrometer(BBS). In connection with this, vacuum boxesfor a HI Detector Unit have been designed; theproduction of these boxes will start in 2005.

The production of components of the high-energy beamline for TRIP such as movable andfixed slits and adapters has been completed in2004; the production of the supports for thevacuum chambers in the beam line and theframes needed for the new correction magnetshave been contracted out. The design andproduction of a lot of additional componentsfor the high-energy beamline such as target-mechanisms, foils, adapters, hall probes, awedge and a target chamber were also realizedthis year.

Together with the Atomic Physics groupwe made an ion optics system that dealt withthe specific constraints of the AGORA exper-iment (transparency for pumping and light).With the AGORA setup, the interaction be-tween comets and the solar wind is studied(see the Atomic Physics section). The ion op-tics system has been successfully implementedand tested. Furthermore, for Atomic Physics,we have been working on small modificationson the existing Atomic Physics setups, such asoptical boxes, small ovens and targets.

For the TRIP laser laboratory, a numberof diode laser boxes, beam dumps, MOT coils,a doubling cavity enclosure and an additionaloven have been realized. For the BINA ex-periment a setup for the mounting of the newtarget has been designed, the production of theparts hereof has been contracted out. For theRIASH project we assisted with the produc-tion of several parts and adaptations to the

cryostat.

Design studies were done concerning a re-placement of the MUF (multi user facility)setup into another section of the KVI building.For radio biologic experiments a moving shield-ing block has been made and the production ofsome collimators has been contracted out. Forthe AGOR cyclotron the production and in-tensive testing of the new EMC-1 extractionchannel has been finished beginning 2004. Af-ter that, the new extraction channel has beeninstalled and implemented successfully in theAGOR cyclotron. At the end of the year how-ever, a problem appeared with the isolation ofsome coils. The AGOR project group is solv-ing this problem now. Furthermore, through-out the year, some small modifications on theexisting equipment of AGOR were carried out.

An upgrade of the interior parts of theAGOR-ECRIS, based on the design of aJyvaskyla- ECRIS, has been realized duringthe second part of 2004. This job included avacuum chamber, the injection and the extrac-tion section, stainless steel boxes around themagnets for closing them against the water-cooling, isolation parts and a rail constructionfor mounting the parts. Testing and installa-tion of this modified ECRIS will take place in2005. A shielding cylinder has been made fortesting the ECRIS.

The final design of the RFQ has been fin-ished, including the design of a drift tube. Theproduction of the RFQ has been started andwill be finished in 2005. Design and produc-tion of the TRIP-LEB (low energy beam line)for the RFQ has been started too. A thermo-ionizer has been made together with the TRIPgroup. The new CNC milling machine DMU60T we purchased last year, has been imple-mented in the workshop successfully. For astart we could only program the new machinedirectly from the machine. However, beginning2004 we implemented a Unigraphics postpro-cessor for the new 5 axis milling machine. We

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are now able to program the machine throughour 3D CAD/CAM system Unigraphics, thisfor more complicated shapes, directly from thedrawing. We also purchased two new worksta-tions, one for the drawing office and one for

the workshop. The operation system for allthe workstations has been upgraded by our ITcolleagues to Windows XP professional. TheUnigraphics CAD/CAM software has been up-graded to NX2.

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8.3 Activities of the research technicians

P. Dendooven, G. Ebberink, I. Formanoy, H. Fraiquin, L. Huisman, H. Kiewiet, R. Kremers, J. Mul-der, F. Rengers, J. Sijbring, H. Timersma, N. de Vries

The research technicians group provides awide range of technical and organisational ser-vices to the experimental research at the KVI.Foremost, the group is heavily involved in thedesign, construction, modification and main-tenance of scientific equipment. These activi-ties include a.o. project management, techni-cal design studies and the commissioning ofnew equipment. Strongly related to this isthe operation of some of the experimental in-frastructure, more specifically the AGOR ionsources and the target laboratory. Support toexperiments, mostly in the preparation phase,is given as well. A general overview of the mainactivities of the group in 2004 is given here.More details are found throughout this annualreport.

The operation and development of theAGOR ion sources is to a large extent carriedout by research technicians. The developmentof metal beams from the AGOR electron cy-clotron resonance (ECR) ion source has con-tinued. The design and construction of a newECR ion source for AGOR has greatly pro-gressed.

Research technicians play a crucial rolein the design and realization of the equip-ment related to the TRIµP programme. Re-search technicians serve as project managersfor the overall infrastructure, separator, radio-frequency quadrupole and low-energy beamlines and provide technical input to the de-sign of these items. A lot of work was per-formed on the installation and commisioningof the TRIµP separator. In 2004, the radio-frequency quadrupole (RFQ) and low-energybeam line changed from the development tothe construction/purchasing phase. At the endof the year, the RFQ parts were ready to beput together.

The radiobiology programme receives sub-stantial support from the research technicians;both in maintaining and developing the equip-ment as well as in running the experiments.

An upgrade and extension of the detec-tor gas recycler for use with BINA and theBBS focal plane detectors was completed. Dueto foreseen changes in the KVI scientific pro-gramme, the plan to use a GEM detector foron-line control of the gas purity has been can-celled.

The FEMLAB finite-element softwarepackage has been used to simulate the ovenused for the production of metal beams withthe AGOR ECR ion source. A problem ofblocking of the exit tube of the oven was causedby a too low temperature at that point. Thefact that this could be verified by the FEM-LAB simulations illustrates the power and use-fulness of such simulations in technical design.

Cryogenic techniques continue to be animportant field of expertise. Developmentsaround existing liquid hydrogen targets con-tinue. Construction of the new liquid heliumtarget is close to completion. A cryostat for theRIASH (Radioactive Ions and Atoms in Super-fluid Helium) project was designed, purchasedand shown to live up to expectations.

Figure 1: KVI research technician Ivo Formanoypresents the AGOR ECR ion source to an attentive au-dience during the first Network Day for FOM researchtechnicians.

On May 13, 2004, the KVI research techni-cians organized the first Network Day for FOMresearch technicians (Figure 1). The largenumber of participants (close to 40) clearlyshows the interest, and thus the usefulness, of

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a network for research technicians. The workof the KVI research technicians was illustratedwith two presentations. A tour of the differentlaboratories where research technicians are ac-tive, as well as the AGOR cyclotron and ex-perimental hall was very much appreciated. Inthe closing discussion, it was agreed to collectthe expertise of all FOM research techniciansand make this available via the FOM web site[1]. The FOM Research Technicians meetingin 2005 will be organized by the FOM Insti-tute for Plasma Physics in Rijnhuizen.

Target laboratory: TaN powder targetsH. Fraiquin To measure the reaction14N(3He,p)16O some melamine targets(C3H6N6) were prepared. During the experi-ment however no 14N but only 12C reactionsappeared, probably because of the carboniz-ing of the melamine target owing to the heatdissipation of the beam. So we searched foranother 14N compound which could withstandthe heat. Besides, the target should preferablybe held at 600 C to prevent carbon contami-nations. We selected TaN. To prepare a TaNtarget a 0.1 mm Ta foil was resistive heated

in a NH4 vapor. Some TaN was formed buttoo low for our demands. An alternative couldbe TaN powder on a thin Ta backing. Aftersome experiments we prepared some 2 mg/cm2

TaN powder targets on a 5 µm Ta backing inthe following way. TaN powder was siftedand mixed in alcohol and next airbrushed ona 5 µm Ta backing. After drying, the foilwas packed between two Hasberg strips andnext to some Al foil to prevent shifting duringrolling. Afterwards this packet was carefullyrolled in a stainless steel envelope to increasesticking of the TaN powder to the Ta backing.The experiments (in Debrecen, Hungary) withthese targets were very successful. The TaNpowder target withstood the beam and afterone week of continuous bombardment (3He,2.3 Mev, 450 nA) the yield was still more than70 %. Using the KVI prepared TaN targets,a magnetic monopole transition was identifiedfor the first time. In the same way we preparedsome 10B, 11B, BN, 12C and13C targets in therange of 0.7-1.7 mg/cm2.

[1] www.fom.nl/personeelsinfo/technici/technici.htm

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Chapter 9

Publications and ScientificPresentations

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9.1 List of publications

M.M. Aggarwal, Z. Ahammed, A.L.S. Angelis, V. An-tonenko, V. Arefiev, V. Astakhov, V. Avdeitchikov,T.C. Awes, P.V.K. S. Baba, S.K. Badyal, S. Bathe,B. Batiounia, T. Bernier, K.B. Bhalla, V. S. Bha-tia, C. Blume, D. Bucher, H. Busching, L. Carlen,S. Chattopadhyay, M.P. Decowski, H. Delagrange, P.Donni, M.R. Dutta Majumdar, K. El Chenawi, A.K.Dubey, K. Enosawa, S. Fokin, V. Frolov, M.S. Ganti,S. Garpman, O. Gavrishchuk, F.J.M. Geurts, T.K.Ghosh, R. Glasow, B. Guskov, H.A. Gustafsson, H.H.Gutbrod, I. Hrivnacova, M. Ippolitov, H. Kalechof-sky, K. Karadjev, K. Karpio, B.W. Kolb, I. Kosarev,I. Koutcheryaev, A. Kugler, P. Kulinich, M. Kurata,A. Lebedev, H. Lohner, L. Luquin, D.P. Mahapatra,V. Manko, M. Martin, G. Martınez, A. Maximov, Y.Miake, G.C. Mishra, B. Mohanty, M.-J. Mora, D. Mor-rison, T. Moukhanova, D.S. Mukhopadhyay, H. Naef,B.K. Nandi, S.K. Nayak, T. K. Nayak, A. Nianine,V. Nikitine, S. Nikolaev, P. Nilsson, S. Nishimura,P. Nomokonov, J. Nystrand, A. Oskarsson, I. Otter-lund, T. Peitzmann, D. Peressounko, V. Petracek, S.C.Phatak, W. Pinganaud, F. Plasil, M.L. Purschke, J.Rak, R. Raniwala, S. Raniwala, N.K. Rao, F. Retiere,K. Reygers, G. Roland, L. Rosselet, I. Roufanov, C.Roy, J.M. Rubio, S.S. Sambyal, R. Santo, S. Sato, H.Schlagheck, H.-R. Schmidt, Y. Schutz, G. Shabratova,T.H. Shah, I. Sibiriak, T. Siemiarczuk, D. Silvermyr,B.C. Sinha, N. Slavine, K. Soderstrom, G. Sood, S.P.Sørensen, P. Stankus, G. Stefanek, P. Steinberg, E.Stenlund, M. Sumbera, T. Svensson, A. Tsvetkov, L.Tykarski, E. C. van der Pijll, N. van Eijndhoven, G.J. van Nieuwenhuizen, A. Vinogradov, Y. P. Viyogi,A. Vodopianov, S. Voros, B. Wyslouch, G.R. Young(WA98 Collaboration)Interferometry of direct photons in central 208Pb+208Pbcollisions at 158A GeVPhys. Rev. Lett. 93 022301 (2004)

M.J. Anagnostakis, C. Bolzan, P. De Felice, A. Fazio,G. Grisanti, S. Risica, T. Turtiainen, E. van der GraafA preliminary intercomparison of gamma-ray spec-troscopy on building materialsAppl. Radiation Iso. 61, 381 (2004)

H. Arenhovel, J. Carbonell, L. Canton, A. Fonseca, W.Glockle, H. Hofmann, A. Kievsky, W. Leidemann, G.Orlandini, R. Timmermans, M. VivianiThe importance of few-nucleon physics at low energyRefereed review; nucl-th/0412039 (2004)

V. Avdechikov, R. Ghetti, J. Helgesson, B. Jakobsson,P. Golubev, N. Colonna, H.W. WilschutAnalysis of charged particle emission sources and co-alescence in E/A=61 MeV 36Ar + 27Al, 112Sn and124Sn collisionsNucl. Phys. A 736, 22 (2004)

J. Aysto, A. Baldini, A. Blondel, A. de Gouvea, J. El-

lis, W. Fletscher, G.F. Giudice, K. Jungmann, S. Lola,V. Palladino, K. Tobe, A. Vacchi, A, van der SchaafPhysics with low-energy muons at a neutrino factorycomplexIn: ECFA/ECRN studies of a European neutrino fac-tory complex, A. Blondel et al. (eds.), (CERN neutrinofactory, Yellow report), p. 254 (2004)

G.W. Bennett, B. Bousquet, H.N. Brown, G. Bunce,R.M. Carey, P. Cushman, G.T. Danby, P.T. Debevec,M. Deile, H. Deng, S.K. Dhawan, V.P. Druzhinin, L.Duong, F.J.M. Farley, G.V. Fedotovich, F.E. Gray,D. Grigoriev, M. Grosse-Perdekamp, A. Grossmann,M.F. Hare, D.W. Hertzog, X. Huang, V.W. Hughes,M. Iwasaki, K. Jungmann, D. Kawall, B.I. Khazin, F.Krienen, I. Kronkvist, A. Lam, R. Larsen, Y.Y. Lee, I.Logashenko, R. McNabb, W. Meng, J.P. Miller, W.M.Morse, D. Nikas, C.J.G. Onderwater, Y. Orlov, C.S.Ozben, J.M. Paley, Q. Peng, C.C. Polley, J. Pretz, R.Prigl, G. zu Putlitz, T. Qian, S.I. Redin, O. Rind, B.L.Roberts, N. Ryskulov, Y.K. Semertzidis, P. Shagin,Yu.M. Shatunov, E.P. Sichtermann, E. Solodov, M.Sossong, L.R. Sulak, A. Trofimov, R. von Walter, A.YamamotoMeasurement of the negative muon anomalous mag-netic moment to 0.7 ppmPhys. Rev. Lett. 92, 161802 (2004)

D. Bodewits, Z. Juhasz, R. Hoekstra, A.G.G.M. Tie-lensCatching some sun: probing the solar wind withcometary x-ray and far-ultraviolet emissionAstrophy. J. Lett. 606, 81 (2004)

D. Bodewits, R.W. McCullough, A.G.G.M. Tielens, R.HoekstraX-ray and far-ultraviolet emission from comets: Rele-vant charge exchange processesPhys. Scr. CAMOP. 70, 17 (2004)

M.J.G. Borge, U.C. Bergmann, R. Boutami, J. Ced-erkall, P. Dendooven, L.M. Fraile, H.O.U. Fynbo,W.X. Huang, J. Huikari, Y. Jading, H. Jeppesen,A. Jokinen, B. Jonson, I. Martel, M. Meister, T. Nils-son, G. Nyman, Y. Prezado, K. Riisager, O. Tengblad,L. Weissman, K. Wilhelmsen, J. AystoBeta-delayed multiparticle emission studies at ISOL-type facilitiesNucl. Phys. A 746, 243c (2004)

S. Brandenburg, W.K. van Asselt, M.A. Hofstee, H.PostVertical beam motion in the AGOR cyclotronProc. EPAC 2004, Luzern, Switzerland, 5 – 9 July2004, pg. 1384

G.L. Caia, V. Pascalutsa, J.A. Tjon, L.E. Wrightγ*N∆gform factors from a relativistic dynamical model

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of pion electroproductionPhys. Rev. C 70, 032201 (2004); nucl-th/0407069

R. Caplar, J.C.S. Bacelar, R. Castelijns, K. Ermisch,I. Gasparic, M.N. Harakeh, N. Kalantar-Nayestanaki,M. Kis, Lohner, M. Mahjour-ShafieiDilepton and double-photon production in proton-proton scattering at 190 MeVActa Phys. Hungarica New Series-Heavy Ion Phys. 19,163-164 (2004)

X.-S. Chen, R.G.E. Timmermans, W.-M. Sun, H.-S.Zong, F. WangExamination of the strangeness contribution to the nu-cleon magnetic momentPhys. Rev. C 70, 015201 (2004)

E.N.E. van Dalen, A.E.L. DieperinkBulk viscosity in neutron stars from hyperonsPhys. Rev. C 69, 025802 (2004); nucl-th/0311103

P. DendoovenGeen zilveren medailles, soms gedeeld goud – een ki-jkje in de moderne keuken van het ontdekken vanscheikundige elementenMUON Vol. 36, No. 92, p. 4-9 (2004)

A.E.L. Dieperink, D. Van Neck, Y. Dewulf, V. RodinNuclear equation of state and neutron star structureProceedings of the Advanced Research Workshop on”Superdense QCD Matter and Compact Stars”, Yere-van, Armenia, September 27, 2003; nucl-th/0312012(2004)

A.G. Drentje, A. Kitagawa, M. Muramatsu, H. Ogawa,Y. SakamotoExperiments with biased cylinder in electron cyclotronresonance ion sourceRev. Sci. Instrum. 75, 1399 (2004)

G. Erkol, Th. A. Rijken, R.G.E. TimmermansMeson-baryon coupling constants in QCD sum rulesProceedings of the 19th European Conference on Few-Body Problems in Physics, Groningen, the Nether-lands, August 23-27, 2004

F.J.M. Farley, K. Jungmann, J.P. Miller, W.M. Morse,Y.F. Orlov, B.L. Roberts, Y.K. Semertzidis, A. Silenko,E.J. StephensonNew method of measuring electric dipole moments instorage ringsPhys. Rev. Lett. 93, 052001/1-4 (2004)

J.L. Friar, U. van Kolck, M.C.M. Rentmeester, R.G.E.TimmermansNucleon-mass difference in chiral perturbation theoryand nuclear forcesPhys. Rev. C 70, 044001; nucl-th/0406026 (2004)

H. Fujimura, H. Akimune, I. Daito, M. Fujiwara, K.

Hara, K.Y. Hara, M.N. Harakeh, F. Ihara, T. Inomata,K. Ishibashi, T. Ishikawa, T. Kawabata, A. Tamii, M.Tanaka, H. Toyokawa, T. Yamanaka, M. YosoiNuclear structure of the spin-isospin excited states in13N studied via the ( 3He,t) and ( 3He,tp) reactions at450 MeVPhys. Rev. C 69, 064327 (2004)

H.O.U. Fynbo, C.A. Diget, Y. Prezado, J. Aysto,U.C. Bergmann, J. Cederkall, P. Dendooven,L.M. Fraile, S. Franchoo, B.R. Fulton, W. Huang,J. Huikari, H. Jeppesen, A. Jokinen, B. Jonson,P. Jones, U. Koster, M. Meister, T. Nilsson, G. Nyman,M.J.G. Borge, K. Riisager, S. Rinta-Antila, I. Stor-gaard Vogelius, O. Tengblad, M. Turrion, Y. Wang,L. Weissman, K. Wilhelmsen and the ISOLDE Collab-orationNews on 12C from β-decay studiesNucl. Phys. A 738, 59 (2004)

R. Ghetti, V. Avdeichikov, B. Jakobsson, P. Golubev,J. Helgsson, N. Colonna, G. Tagliente, H.W. Wilschut,S. Kopecky, V.L. Kravchuk, E.W. Anderson, P. Nadel-Turonski, L. Westerberg, V. Bellini, M.L. Sperduto, C.SuteraIsospin effects on two-particle correlation functions inE/A=61 MeV 36Ar + 112,124Sn reactionsPhys. Rev. C 69, 031605 (2004)

R.Ghetti, N. Colonna, J. Helgesson, V. Avdeichikov, P.Golubev, B. Jakobsson, G. Tagliente, S. Brandenburg,V.L. Kravchuk, H.W. Wilschut, S. Kopecky, E.W. An-derson, P. Nadel-Turonski, L. Westerberg, L. Bellini,M.L. Sperduto, C. SuteraCalibration of a neutron time-of-flight multidetectorsystem for an intensity interferometry experimentNucl. Instrum. Methods A 516, 492 (2004)

R. Ghetti, J. Helgesson, V. Avdeichikov, B. Jakobsson,N. Colonna, H.W. WilschutIsospin effects on particle emission time sequence inE/A=61 MeV 36Ar + 112,124Sn reactionsPhys. Rev. C 70, 034601 (2004)

M.L. Gorelik, I.V. Safonov, M.H. UrinOvertones of isoscalar giant resonances in mediumheavy and heavy nucleiPhys. Rev. C 69, 054322 (2004)

E.W. Grewe, C. Baumer, A.M. van den Berg, N. Blasi,B. Davids, D. De Frenne, D. Frekers, P. Haefner, M.N.Harakeh, M. Huynyadi, E. Jacobs, B. Junk, A. Korff,A. Negret, P. von Neumann-Cosel, L. Popescu, S. Rak-ers, H.J. WortcheGamow-Teller transitions to 32P studied through the32S(d,2He) reaction at Ed= 170 MeVPhys. Rev. C 69, 064325 (2004)

J. Guillot, D. Beaumel, A.M. van den Berg, S. Bran-denburg, B. Davids, S. Fortier, S. Gales, M. Fujiwara,

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M.N. Harakeh, M. Hunyadi, M. de Huu, H.J. WortcheInvestigation of IVGRs via the (t,3He) reaction on 58NitargetNucl. Phys. A 731, 106 (2004)

J. Guillot, C. Baumer, D. Beaumel, A.M. van denBerg, S. Brandenburg, G. Colo, B. Davids, S. Fortier,D. Frekers, E.-W. Grewe, M. Fujiwara, S. Gales, P.Haefner, M.N. Harakeh, M. Hunyadi, M. de Huu, B.C.Junk, E. Rich, N. Van Giai, S.Y. van der Werf, H.J.WortcheInvestigation of isovector excitations via the (t,3He)reaction at Et=43 MeV/u on 58Ni and 48Ca targets:microscopic interpretationProceedings of the International Nuclear Physics Con-ference “INPC 2004”, Goteborg, Sweden, 27 June – 2July 2004

M. Hagemann, A.M. van den Berg, D. De Frenne, V.M.Hannen, M.N. Harakeh, J. Heyse, M.A. de Huu, E. Ja-cobs, K. Langanke, G. Martınez-Pinedo, H.J. WortcheHigh-resolution determination of GT strength distribu-tions relevant to the presupernova evolution using the(d, 2He) reactionPhys. Lett. B 579, 251 (2004)

S. HamiehPolarization enhancement in the d(p,n)2He reaction:nuclear teleportationJ. Phys. A: Math. Gen. 37, L59 (2004)

S. HamiehEffect of the unpolarized spin state in spin-correlationmeasurement of two protons produced in the 12C(d,2He)reactionJ. Phys. A: Math. Gen. 37, 2777 (2004)

S. Hamieh, R. Kobes, H. Zaraket,Positive-operator-valued measure optimization of clas-sical correlationPhys. Rev. A 70, 052325 (2004)

S. Hamieh, H.J. Wortche, C. Baumer, A.M. vanden Berg, D. Frekers, M.N. Harakeh, J. Heyse, M.Hunyadi, M.A. de Huu, C. Polachic, C. RangacharyuluTesting quantum correlations with nuclear probesJ. Phys. G 30, 481 (2004)

M.N. HarakehGiant resonance research: present interests and futureperspectivesNucl. Phys. A 731, 411 (2004)

M.N. Harakeh, J. AystoNuPECC’s longe-range plan: perspectives for nuclearphysics research in EuropeNucl. Phys. News Int. 14, 31 (2004)

M.N. Harakeh, J. AystoPerspectives for nuclear-physics research in Europe

CERN Courier 44, 22 (2004)

J. Huikari, P. Dendooven, A. Jokinen, A. Nieminen,H. Penttila, K. Perajarvi, A. Popov, S. Rinta-Antila,J. AystoProduction of neutron deficient rare isotope beams atIGISOL; on-line and off-line studiesNucl. Instrum. Methods B 222, 632 (2004)

M. Hunyadi, C. Baumer, A.M. van den Berg, N. Blasi,M. Csatlos, L. Csige, B. Davids, U. Garg, J. Gulyas,M.N. Harakeh, M. de Huu, B.C. Junk, A. Kraszna-horkay, S. Rakers, D. Sohler, H.J. WortcheParticle decay of the isoscalar giant dipole resonancein 208PbNucl. Phys. A 731, 49 (2004)

M. Itoh, H. Sakaguchi, M. Uchida, T. Ishikawa, T.Kawabata, T. Murakami , H. Takeda, T. Taki, S.Terashima, N. Tsukahara, Y. Yasuda, M. Yosoi, U.Garg, M. Hedden, B. Kharraja, M. Koss, B.K. Nayak,S. Zhu, H. Fujimura, M. Fujiwara, K. Hara, H.P.Yoshida, H. Akimune, M.N. Harakeh, M. VolkertsThe effect of deformation in the isoscalar giant dipoleresonanceNucl. Phys. A 731, 41 (2004)

K. JungmannFundamental Symmetries and InteractionsPhysics with a Multi-Megawatt Proton Source, A.Blondel et al. (eds.) pp. 118, CERN-SPSC-2004-024SPSC-M-722 (2004)

K. Jungmann, A. Abele, L.Corradi, P. Herczeg, I.B.Khriplovich, O. Naviliat, N.Severijns, L. Simons, C.Weinheimer, H.W. Wilschut, H. Leeb, C. BargholtzFundamental Interactions – Draft Report of the Nu-PECC Long Range Working Group(NuPECC Working Group Fundamental Interactions)(2004)

N. Kalantar-NayestanakiSearch for three-body force effects in elastic proton-deuteron scatteringProceedings of the 17th International Conference onFew-Body Problems in Physics, Durham, North Car-olina, U.S.A. June 2003, Nucl. Phys. A 737, 185 (2004)

A. Kitagawa, M. Muramatsu, M. Sasaki, S. Yamada,T. Sakuma, N. Sasaki, H. Takahashi, W. Takasugi, M.Yamamoto, S. Biri, K. Sudlitz, A.G. DrentjeStatus report on ECR ion sources at HIMACRev. Sci. Instrum. 75, 1476 (2004)

S. Knoop, R. Morgenstern, R. HoekstraDirect observation of pure one-electron capture fromthe target inner shell in low-energy p+Na collisionsPhys. Rev. A 70, 050702(R) (2004)

S. Kondratyuk, K. Kubodera, F. Myhrer, O. Scholten

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The Adler-Weisberger and Goldberger-Miyazawa-Oehme sum rules as probes of constraints from ana-lyticity and chiral symmetry in dynamical models forpion-nucleon scatteringNucl. Phys. A 736, 339 (2004)

R.L. Koomans, R.J. de MeijerDensity gradation in cross-shore sediment transportCostal Engineering 51, 1105 (2004)

A. Yu. Korchin, O. Scholten, A. UsovMicroscopic calculation of gauge-restoring termsProceedings of the Workshop on I3 European Networkon Hadron Physics, St. Andrews, Scotland, August 30– September 1, 2004

A. Korff, P. Haefner, C. Baumer, A.M. van den Berg,N. Blasi, B. Davids, D. De Frenne, R. de Leo, D.Frekers, E.-W. Grewe, M.N. Harakeh, F. Hofmann,M. Hunyadi, E. Jacobs, B.C. Junk, A. Negret, P. vonNeumann-Cosel, L. Popescu, S. Rakers, A. Richter,H.J. WortcheDeuteron elastic and inelastic scattering at intermedi-ate energies from nuclei in the mass range 6 ≤ A ≤116Phys. Rev. C 70, 067601 (2004)

M. Kotulla, J. Ahrens, J.R.M. Annand, R. Beck, D.Hornidge, S. Janssen, B. Krusche, J.C. McGeorge,I.J.D. MacGregor, J.G. Messchendorp, V. Metag, R.Novotny, M. Pfeiffer, R.O. Owens, M. Rost, S. Schad-mand, D.P. WattsDouble π0Photoproduction off the Proton at ThresholdPhys. Lett. B 578, 63 (2004)

A. Krasznahorkay, H. Akimune, A.M. van den Berg,N. Blasi, S. Brandenburg, M. Csatlos, M. Fujiwara, J.Gulyas, M.N. Harakeh, M. Hunyadi, M. de Huu, Z.Mate, D. Sohler, S. Y. van der Werf, H.J. Wortche, L.ZolnaiNeutron-skin thickness in neutron-rich isotopesNucl. Phys. A 731, 224 (2004)

H.R. Kremers, J.P.M. Beijers, N. Kalantar-Nayestanaki, T.B. CleggThe KVI Lamb shift polarimeterNucl. Instrum. Methods A 516, 209 (2004)

G. Leegsma-Vogt, S.Y. van der Werf, K. Venema, J.KorfModeling cerebral arteriovenous lactate kinetics afterintravenous lactate infusion in the ratJ. Cerebral Blood Flow & Metabolism 24, 1071-1080(2004)

R. Lindsay, R.J. de Meijer, A.D. Joseph, T.G.K. Motl-habane, R.T. Newman, S.A. Tsela, W.J. SpeelmanMeasurement of radon exhalation from a gold-minetailings dam by γ-ray mappingRadiat. Phys. Chem. 71, 797 (2004)

R. Lindsay, R.J. de Meijer, P.P. Maleka, R.T. Newman,T.G.K. Motlhabane, D. de VilliersMonitoring the radon flux from gold-mine dumps byγ-ray mappingNucl. Inst. and Meth. in Phys. Res. B 213, 775 (2004)

M.K. Liou, T.D. Penninga, R.G.E. Timmermans, B.F.GibsonSoft-photon analysis of nucleon-nucleon bremsstrah-lung: Anomalous magnetic moment effectsPhys. Rev. C 69, 011001 (2004)

C.-P. Liu, R.G.E. TimmermansP- and T-odd two-nucleon interaction and the deuteronelectric dipole momentPhys. Rev. C 70, 055501 (2004); nucl-th/0408060

H. Lohner, J. Bacelar, R. Castelijns, J. Messchendorp,S. ShendeHyperon production in photonuclear reactions on p andd: KO-Σ+channelProceedings of the International Symposium on “Elec-trophotoproduction of strangeness on nucleons andnuclei”, Sendai, Japan, 16-18 June, ISBN 981-238-752-8

M. Mahjour-Shaifiei, J.C.S. Bacelar, M.J. vanGoethem, M.N. Harakeh, M. Hoefman, H. Huisman,N. Kalantar-Nayestanaki, H. Lohner, J.G. Messchen-dorp, R.W. Ostendorf, S. Schadmand, O. Scholten, M.Volkerts, H.W. WilschutHigh-precision proton-proton bremsstrhalung measure-ments at 190 MeVPhys. Rev. C 70, 024004 (2004)

M. Mauec, C. RigolletMonte Carlo simulations to advance characterisationof landmines by pulsed fast/thermal neutron analysisApplied Radiation and Isotopes 61, 35 (2004)

M. Mauec, R.J. de Meijer, C. Rigollet, P.H.G.M. Hen-driks, D.G. JonesDetection of radioactive particles offshore by γ-ray spec-troscopy Part I: Monte Carlo assessment of detectiondepth limitsNucl. Inst. and Meth. in Phys. Res. A 525, 593(2004)

M. Mauec, R.J. de Meijer, M.M.I.P. van der Klis,P.H.G.M. Hendriks, D.G. JonesDetection of radioactive particles offshore by γ-ray spec-troscopy Part II: Monte Carlo assessment of acquisitiontimesNucl. Inst. and Meth. in Phys. Res. A 525, 610(2004)

R.J. de Meijer, E.R. van der Graaf, K.P. JungmannQuest for a nuclear georeactorNucl. Phys. News. Vol 14, No. 2, 20 (2004)

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R.J. de Meijer, E.R. van der Graaf, K.P. JungmannQuest for a nuclear georeactorRad. Phys.and Chem. 71, 769 (2004)

J.G.Messchendorp, H.R. Amir Ahmadi, J.C.S. Bace-lar, A.M. van den Berg, K. Ermisch, E. van Garderen,M.N. Harakeh, H. Huisman, N. Kalantar-Nayestanaki,M. Kis, H. Lohner, M. Mahjour-Shafiei, A. Mehman-doost, H. Mardanpour, M. Volkerts, H. WortchePresent Status and Future Perspectives of Few-BodyStudies at KVIProceedings of the 17th International IUPAP Confer-ence on Few-Body Problems in Physics, S368, ElsevierB.V. (2004)

J.P. Miller, R.M. Carey, V. Logashenko, K.R. Lynch,B.L. Roberts, A. Silenko, G. Bennett, D.M. Lazarus,L.B. Leipuner, W. Marciano, W. Meng, W.M. Morse,R. Prigl, Y.K. Semertzidis, V. Balakin, A. Bazhan, A.Dunikov, B. Khazin, I.B. Khriplovich, G. Silvestrov ,Y. Orlov, K. Jungmann, P.T. Debevec, D.W. Hertzog,C.J.G. Onderwater, C.S. Ozben, E. Stephenson, M.Auzinsh, P. Cushman, R. McNabb, N. Shafer-Ray, K.Yoshimura, A. Aoki, Y. Kuno, A. Sato, M. Iwasaki,F.J.M. FarleyA new experiment to measure the muon electric dipolemomentAIP Conf.Proc. 698, 196 (2004)

R. Morgenstern, R. Hoekstra, S. HoekstraAlterbestimmung mit einzelnen IsotopenPhysik Journal 3, 16 (2004)

B. Mukherjee, J.C.S. Bacelar, J.P.M. Beijers, M.N.Harkakeh, N. Kalantar-Nayestanaki, M. Kis, H.Lohner, M. Mahjour-Shafiei, P. HenrotteA study of proton-induced reactions at 190 MeVEur. Phys. J. A 21, 273 (2004)

M. Muramatsu, A. Kitagawa, Y. Sakamoto, Y. Sato, S.Yamada, H. Ogawa, A.G. Drentje, S. Biri, Y. YoshidaCompact ECR ion source with permanent magnets forCarbon therapyRev. Sci. Instrum. 75, 1925 (2004)

P. Nadel Turonski, A. Atac, B. Bergenwall, J. Blom-gren, S. Brandenburg, S. Dangtip, C. Johansson,J.Klug; S. Kopecky, H. Laurent, L. Nilsson, J. Nyberg,N. Olsson, D. Reistad, P.U. Renberg, L. WesterbergStudies of inelastic-scattering of fast heavy-ionsPhysica Scripta T104, 69 (2004)

A. Negret, T. Adachi, C. Baumer, A.M. van den Berg,G.P.A. Berg, P. von Brentano, D. Frekers, D. DeFrenne, K. Fujita, Y. Fujita, E.-W. Grewe, P. Haefner,K. Hatanaka, M. Hunyadi, M.A. de Huu, H. Johansson,E. Jacobs, Y. Kalmykov, A. Korff, K. Nakanishi, P. vonNeumann-Cosel, T. Ogama, L. Popescu, S. Rakers, A.Richter, N. Ryezayeva, Y. Sakemi, A. Shevchenko, Y.

Shimbara, Y. Shimizu, A. Tamii, Mu. Uchida, H.J.Wortche, M. YosoiDistribution of the GT strength starting from theground state of 14NAIP Conf. Proc. 726, 241 (2004)

C.J.G. Onderwater (on behalf of the µLan collabora-tion)Towards an improved determination of the Fermi cou-pling constant from the µLan xperimentProceedings of the 5th International Workshop on Neu-trino actories & Superbeams (Nu- Fact03), New York,New York, USA, 5-11 June 003;AIP Conf. Proc. 721, 297-300 (2004)

V. Pascalutsa, J.A. TjonPion photoproduction on nucleons in a covarianthadron-exchange modelPhys. Rev. C 70, 035209 (2004); nucl-th/0407068

M. Pfeiffer, J. Ahrens, J.R.M. Annand, R. Beck,G. Caselotti, S. Cherepnya, K. Fohl, L.S. Fog, D.Hornidge, S. Janssen, V. Kashevarov, R. Kondratiev,M. Kotulla, B. Krusche, J.C. McGeorge, I.J.D. Mac-Gregor, K. Mengel, J.G. Messchendorp, V. Metag, R.Novotny, M. Rost, S. Sack, R. Sanderson, S. Schad-mand, A. Thomas, D.P. WattsPhotoproduction of eta-mesic 3HePhys. Rev. Lett. 92, 252001 (2004)

C. Polachic, C. Rangacharyulu, A.M. van den Berg,S. Hamieh, M.N. Harakeh, M. Hunyadi, M.A. de Huu,H.J. Wortche, J. Heyse, C. Baumer, D. Frekers, S.Rakers, J.A. Brooke, P. BuschPolarization correlations of 1S0proton pairs as tests ofBell and Wigner inequalitiesPhys. Lett. A 323, 176 (2004)

L. Popescu, C. Baumer, A.M. van den Berg, D. Frekers,D. De Frenne, Y. Fujita, E.-W. Grewe, P. Haefner, M.Hunyadi, M.A. de Huu, E. Jacobs, H. Johansson, A.Korff, A. Negret, P. von Neumann-Cosel, S. Rakers, N.Ryezayeva, A. Shevchenko, H. Simon, H.J. Wortche,M. YosoiStudy of Gamow-Teller transition strengths in fp-shellnuclei using the 64Ni(d,2He)64Co reactionAIP Conf. Proc. 726, 247 (2004)

S. Rakers, C. Baumer, A.M. van den Berg, B. Davids,D. Frekers, D. De Frenne, Y. Fujita, E.-W. Grewe, P.Haefner, M.N. Harakeh, M. Hunyadi, E. Jacobs, H. Jo-hansson, B.C. Junk, A. Korff, A. Negret, L. Popescu,H. Simon, H.J. WortcheNuclear matrix elements for the 48Ca two-neutrinodouble-beta decay from high-resolution charge-exchangereactionsPhys. Rev. C 70, 054302 (2004)

M.C.M. Rentmeester, R.G.E. Timmermans, J. J. deSwart

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Partial-wave analysis of all proton-proton and neutron-proton data below 500 MeVProceedings of the 19th European Conference on Few-Body Problems in Physics, Groningen, the Nether-lands, August 23-27, nucl-th/0410042 (2004)

A. Robin, A.V. Postnikov, W. HeilandElectronic stopping of keV nitrogen ions interactingwith a Pt(110)(1x2) surface – a tool to characterizeelectronic surfacesProceedings of the 4th International Symposium onAtomic Level Characterizations for New Materials andDevices, JSPS Activity Report 141, 304, (2004)

C. Savkli, F. Gross, J.A. TjonNonperturbative dynamics of scalar field theoriesthrough the Feynman-Schwinger representationPhys. Atom. Nucl.; hep-ph/0404068 (2004)

T. Schlatholter, R. Hoekstra, R. MorgensternCharge driven fragmentation of biologically relevantmoleculesInt. J. Mass Spectr. 233, 173 (2004)

O. ScholtenNucleon-nucleon bremsstrahlungProceedings of the 19th European Conference on Few-Body Problems in Physics, Groningen, the Nether-lands, August 23-27 (2004)

J.M. Schoorl, C. Boix Fayos, R.J. de Meijer, E.R. vander Graaf, A. VeldkampThe 137Cs technique applied to steep Mediterraneanslopes (Part I): the effects of lithology, slope morphol-ogy and land useCatena 57, 15 (2004)

J.M. Schoorl, C. Boix Fayos, R.J. de Meijer, E.R. vander Graaf, A. VeldkampThe 137Cs technique applied to steep Mediterraneanslopes (Part II): landscape evolution and model calibra-tionCatena 57, 35 (2004)

K. Sekiguchi, H. Sakai, H. Witaa, K. Ermisch,W. Glockle, J. Golak, M. Hatano, H. Kamada,N. Kalantar-Nayestanaki, H. Kato, Y. Maeda, J.Nishikawa, A. Nogga, T. Ohnishi, H. Okamura, T.Saito, N. Sakamoto, S. Sakoda, Y. Satou, K. Suda,A. Tamii, T. Uchigashima, T. Uesaka, T. Wakasa, K.YakoPolarization Transfer Measurement for 1H(d,

p )2H

Elastic Scattering at 135 MeV/u and Three NucleonForce EffectsPhys. Rev. C 70, 014001 (2004)

Y.K. Semertzidis, M. Aoki, M. Auzinsh, V. Balakin,A. Bazhan, G.W. Bennett, R.M. Carey, P. Cushman,P.T. Debevec, A. Dudnikov, F.J.M. Farley, D.W. Hert-zog, M. Iwasaki, K. Jungmann, D. Kawall, B. Khazin,

I.B. Khriplovich, B. Kirk, Y. Kuno, D.M. Lazarus,L.B. Leipuner, V. Logashenko, K.R. Lynch, W.J. Mar-ciano, R. McNabb, W. Meng, J.P. Miller, W.M. Morse,C.J.G. Onderwater, Y.F. Orlov, C.S. Ozben, R. Prigl,S. Rescia, B.L. Roberts, N. Shafer-Ray, A. Silenko, E.J.Stephenson, K. YoshimuraA new method for a sensitive deuteron EDM experi-mentAIP Conf. Proc. 698, 200 (2004)

Yu. A. Simonov, J.A. TjonCoupled-channel analysis of the D and DsmesonsPhys. Rev. D 70, 114013; hep-ph/0409361 (2004)

K.E. Stiebing, F.W.N. de Boer, O. Frohlich, H. Boke-meyer, K.A. Muller, K. Bethge, J. van KlinkenA multi-detector array for high energy nuclear e+e−pairspectroscopyJ.Phys. G: Nucl.Part.Phys. 30, L1 (2004)

J.-C. Thomas, L. Achouri, J. Aysto, R. Beraud,B. Blank, G. Canchel, S. Czajkowski, P. Dendooven,A. Emsallem, J. Giovinazzo, N. Guillet, J. Honkanen,A. Jokinen, A. Laird, M. Lewitowicz, C. Longour,F. de Oliveira Santos, K. Perajarvi, M. StanoiuBeta-decay properties of 25Si and 26PEur. Phys. J. A 21, 419 (2004)

M. Uchida, H. Sakaguchi, M. Itoh, M. Yosoi, T.Kawabata, Y. Yasuda, H. Takeda, T. Murakami, S.Terashima, S. Kishi, U. Garg, P. Boutachkov, M. Hed-den, B. Kharraja, M. Koss, B.K. Nayak, S. Zhu, M.Fujiwara, H. Fujimura, H.P. Yoshida, K. Hara, H.Akimune, M.N. HarakehSystematics of the bimodal isoscalar giant dipole reso-nancePhys. Rev. C 69, 051301 (2004)

A. Usov, O. ScholtenKΛ and KΣ photoproduction in a coupled-channelsframeworkProceedings of the 19th European Conference on Few-Body Problems in Physics, Groningen, the Nether-lands, August 23-27, 2004

M. Volkerts, J.C.S. Bacelar, M.J. van Goethem, M.N.Harakeh, M. Hoefman, H. Huisman, N. Kalantar-Nayestaki, S. Kopecky, H. Lohner, J.G. Messchendorp,R.W. Osterndorf, S. Schadmand, O. Scholten, H.W.Wilschut, K. NakayamaExclusive measurement of quasifree proton-neutronbremsstrahlungPhys. Rev. Lett. 92, 202301 (2004)

J. de Vries, R. Hoekstra, R. Morgenstern, T.SchlatholterIonization and fragmentation modes of nucleobases af-ter collisions with multiply charged ionsPhys. Scr. T110, 336 (2004)

89

J.C. Wang, P. Dendooven, S. Hankonen, J. Huikari,A. Jokinen, V.S. Kolhinen, G. Lhersonneau, A. Niemi-nen, K. Perajarvi, S. Rinta-Antilam, J. AystoReinvestigation of the beta-decay of 110MoEur. Phys. J. A 19, 83 (2004)

J. Weda, J. A. TjonEffects of perturbative exchanges in a QCD string modelPhys. Atom. Nucl. hep-ph/0403177 (2004)

H.W. Wilschut, V.L. KravchukDeveloping an “atomic clock” for fission lifetime mea-surementsNucl. Phys. A 734, 156 (2004)

R.G.T. Zegers, H. Abend, H. Akimune, A.M. van den

Berg, H. Fujimura, H. Fujita, Y. Fujita, M. Fujiwara, S.Gales, K. Hara, M.N. Harakeh, T. Ishikawa, T. Kawa-bata, K. Kawase, T. Mibe, K. Nakanishi, S. Nakayama,H. Toyokawa, M. Uchida, T. Yamagata, K. Yamasaki,M. YosoiExcitation and decay of the isovector giant monopoleresonances via the 208Pb(3He,tp) reaction at 410 MeVNucl. Phys. A 731, 121 (2004)

Y.M. Zhao, A. Arima, N. Shimizu, K. Ogawa, N. Yoshi-

naga, O. Scholten

Patterns of the ground states in the presence of random

interactions: nucleon systems

Phys. Rev. C 70, 054322 (2004)

9.2 Ph.D. Theses

M.A. de HuuExperimental determination of the Jπ components ofthe spin-dipole resonance in 12BRijksuniversiteit Groningen, (16 January) 2004

V.L. KravchukDevelopment of an atomic clock for fission lifetimemeasurementsRijksuniversiteit Groningen, (12 March) 2004

D.F.A. WintersPolarization transfer in ion-surface scatteringRijksuniversiteit Groningen, (7 May) 2004

Z. Juhasz

Charge exchange processes that make comets radiateRijksuniversiteit Groningen, (7 June) 2004

M. Mahjour-ShafieiStudy of proton-proton bremsstrahlung towards the elas-tic limitRijksuniversiteit Groningen, (28 June) 2004

M.D. Cozma

Proton-proton bremsstrahlung and elastic nucleon-

nucleon scattering: relativistic formulations

Rijksuniversiteit Groningen, (20 September) 2004

9.3 Contributions to conferences, workshops etc.

Coastal Ecology workshop Antwerpen, Belgium,20- 22 January 2004A.V. de GrootRadiometric characterisation of salt marshestalk

IAEA Expert Meeting on the testing and use ofpulsed neutron generator for de-mining, Univer-sity of Zagreb, Faculty of electrical engineering,Zagreb, Croatia, 25-28 January 2004M. Mauec, R.J. de MeijerAdvancing detector system and data interpretation ofPELANtalk

The XIV symposium on atomic cluster and sur-face physics, La Thuile, Italy, 1-6 February 2004T. Schlatholter, S. Zamith, M. J. J. Vrakking, R. Hoek-straThe response the RNA base uracil to ultrastrong fields

poster

41Ca Workshop, Zurich, Switzerland, 10-11February 2004S. Hoekstra41Ca analysis by atom trappingtalk

Workshop on “Spectroscopic factors”, ECT,Trento, Italy, 2-12 March 2004A.E.L. DieperinkThe nuclear symmetry energy and spectral functionsinvited talk

Nuclear Physics Spring Meeting, jointly orga-nized by the DPG, BNV/SBP, NNV and OPG,Cologne, Germany, 8-12 March 2004E. Traykov, L. Huisman, A. Rogachevskiy, M. Sanchez-Vega, E. Traykov, L. Willmann, H. Wilschut, K. Jung-mann

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The radiofrequency cooler and buncher for the TRIµPfacilitytalk

G.P.A. Berg, 0.C. Dermois, H.H. Kiewiet, H.H.Traykov, H.W. Wilschut, K. JungmannThe current status of the TRIµP separatortalk

R.J. de Meijer, E.R. van der Graaf, K. Jungmann forthe collaborationQuest for a nuclear georeactortalk

M. Sohani, G.P.A. Berg, U. Dammalapati, P. Den-dooven, O. Dermois, G. Ebberink, M. Harakeh, R.Hoekstra, L. Huisman, K.P. Jungmann, H.H. Kiewiet,R. Morgenstern, J. Mulder, A. Rogachevskiy, M.Sanchez-Vega, R. Timmermans, E. Traykov, L. Will-mann, H.W. WilschutTRIµP - A new facility to produce and trap radioactiveisotopesposter

H.J. WortcheAstrophysics related nuclear structure studiesinvited plenary talk

A. Yu. Korchin, O. ScholtenMicroscopic investigation of gauge-restoration proce-dures for strangeness photoproductionposter

O. ScholtenPhoto-induced π-meson production in a coupled chan-nels frameworkposter

A. Usov, O. ScholtenCoupled channels calculations for photo-induced K-Λand K-Σ productionposter

O. ScholtenPhoton-induced π-meson production in a coupled chan-nels frameworkcontributed talk

O. ScholtenA Microscopic calculation of gauge restoring termscontributed talk

A. UsovCoupled channels calculations for photo-induced K-Λand K-Σ productioncontributed talk

R.J. de Meijer, E.R. van der Graaf, K. JungmannQuest for a nuclear georeactor (and other radiogenicheat sources)

talk

E. Traykov, L. Huisman, K. Jungmann, R. Morgen-stern, A. Rogachevskiy, M. Sanchez-Vega, E. Traykov,L. Willmann, H. WilschutTRIµP - A new facility to produce and trap radioactiveisotopesposter

M. Sohani, G.P.A. Berg, U. Dammalapati, P. Den-dooven, O. Dermois, G. Ebberink, M. Harakeh, R.Hoekstra, L. Huisman, K. Jungmann, H.H. Kiewiet, R.Morgenstern, J. Mulder, A. Rogachevskiy, M. Sanchez-Vega, R. Timmermans, E. Traykov, L. Willmann, H.W.WilschutTRIµP - A new facility to produce and trapradioactiveisotopesposter

R. Castelijns (CBELSA/TAPS-Collaboration)Nucleon-resonance decay by the KO-Σ+channeltalk

M. Mahjour-Shafiei, H. Amir-Ahmadi, J.C.S. Bacelar,R. Castelijns, K. Ermisch, E. van Garderen, I. Gaparic,M.N. Harakeh, N. Kalantar-Nayestanaki, M. Kis, H.LohnerReal and virtual proton-proton bremsstrahlunggroup report

A.A. Mehmandoost-Khajed-dad, H. Amir-Ahmadi,J.C.S. Bacelar, A.M. van den Berg, R. Castelijns,E. van Garderen, M.N. Harakeh, N. Kalantar-Nayestanaki, M. Kis, H. Lohner, M. Mahjour-Shafiei,J. Messchendorp, B. Muhkerjee, S.V. Shende, H.J.WortcheA systematic measurement of the proton-deuteron ra-diative capture processtalk

H. Amir-Ahmadi, A. van den Berg, R. Castelijns, E.van Garderen, M. Hunyadi, M.A. de Huu, N. Kalantar-Nayestanaki, M. Kis, H. Lohner, M. Mahjour-Shafiei,S.V. Shende, J. Messchendorp, H.J. WortcheStudy of proton polarimeter of BBS at KVIposter

Deutsche Physikalische Gesellschaft FruhjahrstagungMunchen, Germany 22-26 March 2004U. Dammalapati, G.H.P. Ebberink, K. Jungmann, L.WillmannTrapping of heavy alkaline earth elementsposter

U. Dammalapati, G.P. Berg, P. Dendooven, O. Der-mois, G. Ebberink, M.N. Harakeh, R. Hoekstra, L.Huisman, H.H. Kiewiet, R. Morgenstern, J. Mulder, A.Rogachevskiy, M. Sanchez-Vega, M. Sohani, R.G. Tim-mermans, E. Traykov, L. Willmann, H.W. Wilschut,K. Jungmann

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TRIµP – Trapped Radioactive Isotopes asµicrolaboratories for fundamental Physicsposter

11thInternational Conference on Calorimetryin High Energy Physics, CALOR04, Perugia,Italy, 29 March – 2 April 2004H. LohnerScintillation detectors for radiation-hard electromag-netic calorimetersinvited talk

FGLA spring meeting “Dutch activities in Lab-oratory Astrophysics”, Leiden, the Nether-lands, 16 April 2004D. Bodewits, R. HoekstraCatching some sun: the interaction between comets andthe solar windinvited talk

NIPNET Workshop on High-Precision MassMeasurements, Saariselka, Finland, 18-20 April2004P. DendoovenStoring ions and atoms in superfluid heliumtalk

International Conference on Linear Colliders,Paris, France, 19-23 April, 2004K. JungmannExperimental results on the muon g-2invited talk

Astro Particle Physics Symposium, NIKHEF,Amsterdam, the Netherlands, 26 April 2004A.M. van den BergNuclear and particle astrophysics: from low to highenergiesinvited talk

Mini-Symposium NGD:“Core-business: heatproduction of the Earth”, KVI, Groningen, theNetherlands, 29 April 2004.E. R. van der GraafHeat sources of the Earthtalk

R.J. de MeijerAn antineutrino-antennatalk

International Conference 21stCentury Chal-lenges in Radiation Protection and Shielding,ICRS-10/RPSD, Madeira Island, Portugal, 9-14 May 2004M. Mauec, I.A. KodeliVariance-reduction techniques for Monte Carlo nuclearlogging calculations with neutron sourcestalk

LASER 2004, Poznan, Poland, 24-27 May 2004S. HoekstraAtom trap trace analysis of 41Catalk

Workshop on Physics with a Multi-MW ProtonDriver CERN, Geneva, Switzerland, 25-27 May2004K. JungmannFundamental symmetries and interactionsinvited talk

P. Dendooven, K. Gloos, W.X. Huang, J. Huikari, J.P.Pekola, N. Takahashi, J. Aysto, IGISOL groupRIASH: Radioactive Ions and Atoms in Superfluid He-liumposter

M.N. HarakehPhysics with a multi-MW proton source: Nuclearphysics aspectsinvited talk

59thNederlandse Astronomen Conferentie,Vlieland, the Netherlands, 26-28 May 2004A.M. van den BergNuclear astrophysics at KVIposter

D. Bodewits, R. Hoekstra, A.G.G.M. TielensCatching some sun: the interaction between comets andthe solar windtalk

Joint Collaboration Meeting in Krakow,Krakow, Poland, 3-6 June 2004K. JungmannA tutorial on the g-2 measurement of the muoninvited talk

C.J.G. OnderwaterProspects to measure the EDM of the deutron in a stor-age ringinvited talk

H.W. WilschutNIPNET in he international contextinvited talk

E.K. TraykovA new RFQ cooler: consepts,simulations & statustalk

L. WillmannLow Energy Charge Exchange Studies for Gas CatcherDesigntalk

U. DammalapatiTRIµP laser spectroscopy status and future

92

talk

A. RogachevskiyTRIµP separator: status and futuretalk

R. MorgensternProbing surface magnetism by ion scatteringtalk

10*30 Anniversary Symposium on CyclotronResearch at JYFL, Jyvaskyla, Finland, 18 June2004M.H. HarakehNuclear physics in the coming decade: A European per-spectiveinvited talk

Fundamental Interactions International Work-shop, Trento, Italy, 21-25 June 2004C.J.G. OnderwaterDeuteron EDM: Experimental aspectsinvited talk

L. WillmannSearch for EDMs of radioactive atoms.invited talk

H.W. WilschutAtomic trapping and recoil spectroscopy in beta-decay(and other) studies.invited talk

Manipulation of Few-Body Quantum Dynamics,Bad Honnef, Germany, 23-26 June 2004R. HoekstraCharge transfer studied with MOTRIMS: impact pa-rameter dependencies and inner-shell processesinvited talk

S. Knoop, R. Morgenstern, R. HoekstraDirect observation of inner-shell electron capture at lowenergyposter

RADAM04 conference on Radiation damage inbiomolecular systems, Lyon, France, 25-28 June2004F. AlvaradoIonization, excitation and fragmentation of the isolatednucleobases uracil and thymine by multiply charged ionsinvited talk

The First Meeting of the C12 InternationalCommittee on Cooperation in Nuclear Physics,Goteborg, Sweden, 27 June 2004M.N. HarakehPlanned and under construction international facilitiesin Europeinvited talk

International Nuclear Physics Conference INPC2004, Goteborg, Sweden, 27 June – 2 July 2004K. JungmannFundamental symmetries and interactionsinvited plenary review

European Particle Accelerator Conference 2004,Luzern, Switzerland, 5-9 July 2004S. Brandenburg, W.K. van Asselt, M.A. Hofstee, H.PostVertical beam motion in the AGOR cyclotronposter

ECAMP VIII, European Conference on Atomicand Molecular Physics, Rennes, France, 6-10July 2004T. SchlatholterIonization excitation and fragmentation of nucleobasesby multiply charged ionsinvited talk

D. Bodewits, A.G.G.M. Tielens, R. Morgenstern, R.HoekstraProbing space weather via radiative charge transfer incometsselected talk + poster

F. Alvarado, R. Hoekstra, T. SchlatholterHeq+-probing of photo-excited C60

poster

S. Hoekstra, A. Mollema, R. Morgenstern, R. HoekstraDetection of 41Ca by single atom counting in a MOTposter

S. Knoop, M. Zapukhlyak, T. Kirchner, H.J. Ludde,R. Morgenstern, R. HoekstraDirect observation of inner-shell electron capture at lowenergyposter

ICACS, Genova, Italy, 6-10 July 2004M. Unipan, A. Robin, R. Morgenstern, R. HoekstraSurface spin polarization in Fe(110) and Ni(110)poster

24thWerner Brandt Workshop, Berlin, Ger-many, 12-14 July 2004R. HoekstraInteraction of multiply charged ions with magnetic sur-facesinvited talk

3rdIAEA workshop “Charge Exchange Data forFusion Studies”, Vienna, Austria, 17-18 July2004R. HoekstraCharge transfer data for α particle diagnostics in fu-sion edge plasmas

93

invited talk

Hydrogen Atom III - International Conferenceon Precision Physics of Simple Atomic SystemsMangaratiba, Rio de Janeiro, Brazil, 1-4 Au-gust 2004R. deCarvalho, N. Brahms, B. Newman, C. Johnson,L. Willmann, J. M. Doyle, T. J. Greytak, D. KleppnerA new path to ultracold hydrogenposter

The Gordon conference on Photonuclear reac-tions, Tilton, NH, USA, 1-6 August 2004N. Kalantar-NayestanakiProbing few-body systems with bremsstrahlunginvited talk

J.S. MesschendorpNuclear force studies at KVIposter

R.G.E. TimmermansPartial-wave analysis of NN scattering datainvited talk

19thEuropean Few Body Conference, Gronin-gen, the Netherlands, 23-27 August 2004J.G.O. Ojwang, O. ScholtenThe Dibaryon resonance and two-photon bremsstrah-lung in

p

pscattering

poster

A. Usov, O. ScholtenK-Λ and K-Σ photo-production in a coupled channelsframeworkposter

O. ScholtenNucleon-nucleon bremsstrahlunginvited talk

M. Mahjour-Shafiei, H. Amir-Ahmadi, J.C.S. Bacelar,R. Castelijns, K. Ermisch, E. van Garderen, I. Gaspari,M.N. Harakeh, N. Kalantar-Nayestanaki, M. Kis, H.LohnerProton-proton bremsstrahlung towards the elastic limittalk

H.R. Amir-Ahmadi, J.C.S. Bacelar, A. van den Berg,R. Castelijns, E.D. van Garderen, M. Harakeh, M.Hunyadi, M.A. de Huu, N. Kalantar-Nayestanaki, M.Kis, H. Lohner, M. Mahjour-Shafiei, S.V. Shende, J.G.Messchendorp, H.J. WortcheMeasurement of the effective analyzing power ofgraphite sheet as a function of energyposter

M. Bellos, N. Kalantar-Nayestanaki, R. Kremers, J.G.MesschendorpLow-energy deuteron polarimeter

poster

J.G. MesschendorpThree-nucleon force studies at intermediate energiesinvited talk

M. Kis, J.C.S. Bacelar, R. Castelijns, R. aplar, I.Gaspari, M.N. Harakeh, N. Kalantar-Nayestanaki, H.Lohner, M. Mahjour-Shafiei, J.G. MesschendorpVirtual bremsstrahlung in proton-proton scattering at190 MeVposter

R. Castelijns(CBELSA/TAPS-Collaboration)Nucleon-resonance decay by the KO-Σ+channeltalk

E. van Garderen, H. Amir-Ahmadi, J.C.S. Bacelar,A.M. van den Berg, R. Castelijns, I. Gaspari, M.N.Harakeh, N. Kalantar-Nayestanaki, M. Kis, H. Lohner,M. Mahjour-Shafiei, A.A. Mehmandoost-Khajeh-dad,J.G. Messchendorp, B. Muhkerjee, S.V. Shende, H.J.WortcheMeasurement of the proton-deuteron radiative captureprocessposter

G. Erkol, Th.A. Rijken, R.G.E. TimmermansMeson-baryon coupling constants in QCD sum rulestalk

M.C.M. Rentmeester, R.G.E. Timmermans, J.J. deSwartPartial-wave analysis of all pp and np scattering databelow 500 MeVtalk

B.F. Gibson, T.D. Penninga, R.G.E. Timmermans,M.K. LiouNN bremsstrahlung: Anomalous magnetic moment ef-fectstalk

Americal Physical Society’s 2004 Meeting ofthe Division of Particles and Fields, Riverside,California, USA, 28 August 2004C.J.G. OnderwaterElectric and magnetic dipole measurement of the muontalk

Workshop on I3 European network on HadronPhysics, St. Andrews, Scotland, 30 August-1September 2004O. ScholtenA microscopic calculation of gauge-restoring termscontributed talk

8thWorkshop on Fast Ion Atom Collisions, De-brecen, Hungary, 1-3 September 2004T. Schlatholter

94

Ion – biomolecule interactions and radiation damageinvited talk

12thInternational Conference on the Physics ofHighly Charged Ions, Vilnius, Lithuania, 6-11September 2004R. HoekstraComets as probes of solar wind propertiesinvited talk

T. SchlatholterInteractions of the Heq+with laser excited C60

invited talk

T. Schlatholter, R. Hoekstra, S. Zamith, Y. Ni, H.G.Muller, M.J.J. VrakkingThe response of polyatomic molecules to intense laserand ion induced fieldsposter

S. Knoop, R. Morgenstern, R. HoekstraProgress in MOTRIMS studies of electron capture andionization by multiply charged ionsposter

The Fourth International Conference on ExoticNuclei and Atomic Masses ENAM04, CallawayGardens, USA, 12-16 September 2004K. JungmannFundamental symmetries and interactionsinvited plenary review

International Workshop on later and Nuclei:Application of Ultra-high Intensity Lasers inNuclear Science, Karlsruhe, Germany, 13-14September 2004M. Mauec, J. Galy, T. ZagarBremsstrahlung spectra and electron-photon conversionefficiency in laser experiments using MCNPposter

Workshop on Microscopic Nuclear Structure,INT. University of Washington, Seattle, USA,17 September – 5 December 2004A.E.L. DieperinkThe nuclear symmetry energy and neutron star struc-tureinvited talk

2ndSymposium “Particle Astrophysics in theNetherlands, Radboud University, Nijmegen,The Netherlands, 24 September 2004A.M. van den BergBringing together two extremes in neutrino detection:from low to the highest energiesinvited talk

CERN SPSC meeting Villars-sur-Ollon, 25September 2004K. Jungmann

Slow antiproton physicsinvited review

16th International Workshop on ECR IonSources, Berkeley, USA, 26-30 September 2004J.P.M. Beijers, I. Formanoy, H.R. Kremers, J. Mulder,J. Sijbring, S. BrandenburgStatus report of ECRIS at KVItalk

H.R. Kremers, J.P.M. Beijers, I. Formanoy, J. Sijbring,S. BrandenburgDesign and calculations for the new ECRIS at KVIposter

M. Muramatsu, A. Kitagawa, Y. Sakamoto, S. Sato, Y.Sato, Hu. Ogawa, S. Yamada, Hi. Ogawa, Y. Yoshida,A. G. DrentjeTests of the new NIRS compact ECR ion source forcarbon therapycontributed paper

5thEuropean Radon Forum, European RadonResearch and Industry Collaboration ConcertedAction, St. Albans, United Kingdom, 27-28September 2004E.R. van der GraafDutch radon policy 2004talk

E.R. van der GraafPre- and post construction evaluation tools of radonprotective measures in buildings (final discussion)talk

Fifth International Conference of Yugoslav Nu-clear Society, YUNSC 2004, Belgrade, Serbiaand Montenegro, 27-30 September 2004M. MauecApplication of Nuclear Methods to Earth Sciences andEnvironmental Monitoringposter

International workshop Energy Dissipation atSurfaces, Schloß Eichholz, Germany, 17-30September 2004A. Robin, A.V. Postnikov, W. HeilandCharacterization of the electronic density corrugationby surface channellingposter

Coastal Ecology workshop St.-Malo, France, 4-6 October 2004A.V. de GrootChanging sediment patterns during salt-marsh develop-ment; the chronosequence of Schiermonnikoog (NL)talk

Fermilab Proton Driver Workshop Fermilab,Chicago, USA, 6-8 October 2004

95

K. Jungmann, B. Lee RobertsPrecision measurements in muon physics - A samplerof fundamental measurements with muoniuminvited talk

SPIN 2004 International Conference, Trieste,Italy, 10-16 October 2004K.P. JungmannNew experiments to search for permanent electric dipolemomentsinvited plenary review

Journees de Prospectives DSM/DAPHNIA-IN2P3, Le Colle sur Loup, Nice, France, 13October 2004M.N. HarakehTable ronde: Contexte et perspective en Europeinvited talk

IISC 15, Iso-Shima, Japan, 17-22 October 2004R. HoekstraTransfer of spin-polarization in ion-surface scatteringinvited talk

17th Internationl conference on cyclotrons andtheir applications, Tokyo, Japan, 18-22 October2004S. Brandenburg, W.K. van Asselt, J.P.M. Beijers, I.H.J.Formanoy, M.A. Hofstee, H.R. Kremers, A. Kroon, H.Post, D. ToprekAGOR status reporttalk

S. Brandenburg, W.K. van Asselt, M.A. Hofstee, andH. PostVertical beam motion in the AGOR cyclotronposter

T.W. Nijboer, W.K. van Asselt and S. BrandenburgBeam-phase measurement in the AGOR-cyclotronposter

PESC/ESF Standing Committee meeting, Li-massol, Cyprus, 21-22 October 2004M.N. HarakehNuPECC: Mission, structure and forward lookinvited talk

NNV Najaarsvergadering, Lunteren, theNetherlands, 29 October 2004A. Matic, T. Adachi, G.P.A. Berg, H. Fujita, K. Fu-jita, Y. Fujita, J. Gorres, K. Hatanaka, P. Leblanc,Y. Sakemi, H. Schatz, Y. Shimbara, Y. Shimizu, Y.Tameshige, A. Tamii, T. Wakasa, M. Wiescher, H.J.Wortche, M. YosoiStudy of resonance states in 22Mg and 26Si nuclei usingthe (p,t) reaction and reaction rates in the rp-processestalk

M. Mauec, H.J. Wortche, R.J. de Meijer

Monte Carlo simulations of neutron and positron dis-tribution from inverse neutron beta decaytalk

J.G. MesschendorpSpin observables in proton-deuteron radiative capturetalk

C.J.G. OnderwaterThe deuteron EDMtalk

R.G.E. TimmermansThe search for time reversal violationinvited plenary talk

M. SohaniTRIµP separator status and first production measure-mentstalk

H. Amir-AhmadiMeasurement of the effective analyzing power ofgraphite sheet as a function of energytalk

NNV Lunteren, the Netherlands, 11-12 Novem-ber 2004S. Hoekstra (A. Mollema, L. Wansbeek, R. Morgen-stern, R. Hoekstra)Searching a needle in 10.000 haystacksselected talk

F. Alvarado, R. Hoekstra, T. SchlatholterHe+interactions with laser excited fullerenesposter

F. Alvarado, R. Hoekstra, T. Schlatholter, B. Manil,J. Rangama, B. HuberIon-biomolecule interactions and radiation damageposter

D. Bodewits, A.G.G.M. Tielens, R. HoekstraProbing the interaction between comets and the solarwindposter

S. Knoop, V.G. Hasan, H. Ott, R. Morgenstern, R.HoekstraQuantum-state resolved electron capture usingMOTRIMSposter

S. De, G.P.A. Berg, U. Dammalapati, P. Dendooven,O. Dermois, G. Ebberink, M.N. Harakeh, R. Hoekstra,L. Huisman, K. Jungmann, H. Kiewiet, R. Morgen-stern, J. Mulder, C.J.G. Onderwater, A. Rogachevskiy,M. Sohani, M. Stokroos, R. Timmermans, E. Traykov,L. Willmann, H. WilschutFirst isotopes produced at TRIµP

96

poster

X-ray Diagnostics for Astrophysical Plasmas,Harvard, Boston, USA, 15-17 November 2004D. BodewitsFinding fingerprints: probing the solar wind withcometstalk

FANTOM study week on Symmetries and Sym-metry violation, Gent, Belgium, 15-19 Novem-ber 2004C.J.G. OnderwaterExperimental tests of discrete symmetriesinvited lectures

R.G.E. TimmermansSymmetry in quantum physics: an introductioninvited lectures

2nd INTAS workshop, Caen, France 18-19November 2004J.P.M. BeijersKVI ECRIS status reporttalk

Symposium ”Limits!”, Eindhoven, the Nether-lands, 30 November 2004P. DendoovenSuperzware elementen

invited talk

Workshop on “Nonequilibrium Processes inAtomic Clusters”, Dresden, Germany, 29November - 4 December 2004T. SchlatholterIon and laser induced ionization and fragmentation dy-namics of biomoleculesinvited talk

F. Alvarado, R. Hoekstra, R. Morgenstern, T.SchlatholterCollisions of He+ions with laser excited fullerenesposter

FOM Gecondenseerde Materie, Velthoven, theNetherlands, 14-15 December 2004M. Unipan (A. Robin, D.F.A. Winters, R. Morgen-stern, R. Hoekstra)Surface spin polarization in Ni(110)selected talk

Annual WOG workshop, Leuven, Belgium, 20-

21 December 2004

R. Hoekstra

New atomic physics applications of atom traps

invited talk

9.4 Organized Conferences, workshops etc.

COST workgroup meeting on ions andbiomolecular interactionsGroningen, Netherlands, 5-6 March 2004T. Schlatholter (organizer)

Fundamental Interactions International Work-shopTrento, Italy, 21-25 June 2004K. Jungmann, R. G.E. Timmermans, Ch. Weinheimer(chairmen)

19th European Few-Body Conference, Gronin-

gen, The Netherlands, 23-29 August 2004 J.C.S.

Bacelar, B.L.G. Bakker, N. Kalantar-Nayestanaki

(chairmen), L.P. Kok, J.G. Messchendorp, G. van der

Steenhoven, R.G.E. Timmermans, G. van der Tuin-

Venema

9.5 Internal reports

P.P. Maleka, C. Rigollet, I. Radulescu, M. Mauec andR.J. de MeijerNuPulse BGO detector system verifications and cali-brationsKVI Report NP-006, April 2004

P.P. Maleka, M. Mauec, C. Rigollet, R.J. de MeijerBenchmark experiments for the NuPulse monitoringtoolKVI Report NP-007, June 2004

M. Mauec, R.J. de MeijerNuPulse field testsKVI Report NP-008, November 2004

I. Radulescu, C. Rigollet, E. R. van der GraafSources of the background for detectors: Cosmic-raycontributionKVI Report P-021, June 2004

I. DenijsFeasibility study of a density- meter for PHAROS

97

KVI Report P-022, November 2003

E.R. van der Graaf, R.J. de Meijer, R. ten HaveOn line bepaling van diktes van asfalt-lagen, een haal-baarheidstudie, datarapport en eerste analyseKVI Report PAN-007, October 2003 (not in the annualreport of 2003)

E.R. van der Graaf, R.J. de MeijerOn line bepaling van diktes van asfalt-lagen, een haal-baarheidstudie en analyserapportKVI Report PAN-008, June 2004

E.R. van der Graaf, R.J. de MeijerRaamwerk voor software voor on-line bepaling van as-faltlaagdikte uit radiometrische gegevensKVI Report PAN-009, June 2004

E.R. van der GraafPre- and post construction evaluation tools of radonprotective measures in buildingsKVI Report R-125, November 2004

E.R. van der Graaf, R. ten HaveDetermination of the activity concentrations of naturalradionuclides in 9 samples received from UniversitatBremen, GermanyKVI Report S-115, October 2004

E.R. van der Graaf, R. ten Have

Determination of radon release rates of nine types of

gypsum blocks received from IBR, Haelen, the Nether-

lands

KVI Report S-116, October 2004

9.6 Seminars at KVI

6 January 2004P. Muller, Argonne Nat. Laboratory, Argonne IL, USAAtom trap trace analysis of Kr and He

7 January 2004O. Naviliat-Cuncic, LPC Caen, FranceSearch for exotic couplings in nuclear beta decay

15 January 2004M.A. de Huu, KVI Groningen, the NetherlandsExperimental determination of the Jπcomponents of thespin-dipole resonance in 12B

19 January 2004C. Rangacharyulu, Saskatoon, CanadaThe S=+1 Resonance as a Pentaquark state

20 January 2004P.G. Reinhard, Erlangen, GermanyExotic nuclei - a challenge for nuclear mean field mod-els

23 January 2004P. Van Duppen, Univ. Leuven, BelgiumNuclear structure studies around 68Ni using varioustechniques including post-accelerated radioactive ionbeams

27 January 2004C.J.G. Onderwater, KVI Groningen, the NetherlandsA precise measurement of the anomalous magnetic mo-ment of the negative muon

28 January 2004J.P. Schiffer, Argonne Nat. Laboratory, Argonne IL,USAVaria: What happens to the spin-orbit interaction atlarge neutron excess? and Recent work on the 8B Neu-

trino spectrum”

2 FebruaryE. Stephenson, IUCF, Bloomington IN, USACharge symmetry. breaking measurement at IUCF

9 FebruaryI. Denijs, KVI Groningen, the NetherlandsFeasibility study of a density-meter for Pharos

10 FebruaryL. Vandersypen, TU Delft, the NetherlandsQuantum computing with electron spins in artificialatoms

17 FebruaryJ. Templon, NIKHEF Amsterdam, the NetherlandsLarge scale computing with Grids

18 February 2004H. Toki, RCNP Osaka, JapanChiral symmetry and finite pion mean field in finitenuclei

27 February 2004A. Sedrakian, Univ. Tubingen, GermanyPairing in dense matter

12 MarchV. Kravchuk, KVI Groningen, the NetherlandsDevelopment of an atomic clock for fission lifetimemeasurements

18 MarchG. Alber, Department of Quantum Physics, TU Darm-stadt, GermanyQuantum information and decoherence - possibilitiesand perspectives of quantum information processing”

98

23 MarchV. Tvaskis, JLab, Newport News VA, USALongitudinal-Transverse Separation of the EMC effectat low Q2

30 MarchM. Lindroos, CERN, Geneva, SwitzerlandStorage rings for low energy radioactive ions

2 AprilY. Fujita, RCNP Osaka, JapanNuclear structure renaissance opened by high resolution(3He,t) experiments

20 AprilA. Owens, ESTEC Noordwijk, the NetherlandsCompound semiconductor radiation detectors

21 AprilC.W.J.P. Timmermans, KU Nijmegen, the NetherlandsExperimental status of RUHECR research

27 AprilH. Falcke, ASTRON Dwingeloo, the NetherlandsDetecting ultra-high energy cosmic particles with LO-FAR and LOPES

28 April 2004S. Harrissopulos, Inst. of Nucl. Physics, Athens,GreeceA systematic investigation of proton- and alpha-capturereactions at sub-Coulomb energies relevant to p-processnucleosynthesis

4 May 2004D. Winters, KVI Groningen, the NetherlandsPolarization transfer in ion-surface scattering

7 May 2004J. Gabrielse, Harvard University, Cambridge MA, USAQuantum cyclotron and the first fully-Quantum mea-surement of the electron magnetic moment

12 May 2004A. Haungs, Institut fur Kernphysik FZ Karlsruhe, Ger-manyEnergy spectrum and mass composition of primary cos-mic rays: present status and outlook

12 May 2004H. Rebel, Institut fur Kernphysik FZ Karlsruhe, Ger-manyWhat do we learn about high-energy hadronic interac-tion processes from extensive air shower observations?

17 May 2004T. Koerber, University Innsbruck, AustriaRf-spectroscopy with a single Ba+ ion and prospectsfor a parity violation experiment

1 June 2004Z. Juhasz, KVI Groningen, the NetherlandsCharge exchange processes that make comets radiate

7 June 2004V. Kolhinen, University of Jyvaskyla, FinlandPenning trap for isobaric purification of radioactive ionbeams at IGISOL

15 June 2004O.R. Pols, Department of Physics and Astronomy, Uni-versity of Utrecht, the NetherlandsNucleosynthesis in Asymptotic Giant Branch Stars

22 June 2004C.L. Cocke, Kansas State University, Manhattan KS,USAProbing the dynamics of small molecules on a fs timescale

28 June 2004M. Mahjour-Shafiei, KVI Groningen, the NetherlandsStudy of proton-proton bremsstrahlung towards the elas-tic limit

29 June 2004B. Gibson, LANL, Los Alamos NM, USAH4 inelastic electron scattering

1 July 2004Y. Semertzidis, BNL, Brookhaven NY, USAElectric dipole moments in storage rings

14 September 2004J.H. Posthumus, UCL, Louvain-la-Neuve, BelgiumMolecules in strong laser fields

16 September 2004D. Cozma, KVI Groningen, the NetherlandsRelativistic models for pp bremsstrahlung and elasticNN scattering

21 September 2004H. Chang, FOM Utrecht, the NetherlandsZeepkistverhaal

28 September 2004S. Lacombe, MCCP, Universite Paris-Sud, FranceIon induced DNA damage in solution and at surfaces

5 October 2004V. Flambaum, University of New South Wales, Aus-traliaVariation of fundamental constants

26 October 2004R. Nahnhauer, DESY Zeuthen, GermanyDetection methods for high energetic cosmic neutrinos

99

2 November 2004H. Fynbo, Arhus University, DenmarkNew information on 12C and implications for the triple-alpha reaction in stars

8 November 2004M. Herbane, GANIL, Caen, FranceMeasurement of the β − ν angular correlation parame-ter in 6He beta decay using a transparent Paul trap

23 November 2004H. Ott, KVI Groningen, the NetherlandsUltracold bosonic and fermionic atoms in a periodicpotential

9 December 2004S. Gensemer, University of Amsterdam, the Nether-lands

Light and collisions in ultracold atomic Gases

15 December 2004N. van Eijndhoven, Department of Physics and Astron-omy, University of Utrecht, the NetherlandsNeutrinos: The ultimate cosmic messengers

20 December 2004R.J. de Meijer, KVI Groningen, the NetherlandsFeasibility of directional sensitive, low-energy antineu-trino detection

21 December 2004Deepak Mathur, Atomic & Molecular Sciences, TataInstitute of Fundamental Research, Mumbai, IndiaMolecules in very strong fields

9.7 Seminars and colloquia given by staff members outside KVI

C.J.G. OnderwaterA precise measurement of the anomalous magnetic mo-ment of the negative muonBrookhaven National Laboratory, Upton, New York,USA, 8 January 2004

T. Nijboer, C. Rigollet, M.A. Hevinga, R.J. de MeijerSurface Control UnitNuPulse Mid-term meeting Groningen, the Nether-lands, January 2004

V.L. KravchukFhe fission time scale measured with an atomic clockNational Laboratory, Legnaro, Italy, 27 February 2004

A. G. DrentjeHigher output of highly charged ions with ECR ionsourcesRCNP, Osaka University, Osaka, Japan, 2 March 2004

A. G. DrentjeExperiments to understand better the ECR ion sourceperformanceBio-Nano Research Centre, Toyo University, Kawagoe,Japan, 10 March 2004

R.J. de MeijerA radioactive heart for Mother Earth?Colloquium Physics Department, University of theWestern Cape, South Africa, 11 March 2004

R.J. de MeijerFrom Surface to CoreColloquium iThemba Labs, South Africa, March 2004

V.L. KravchukAt atomic clock for fission lifetime measurementsUniversity of Florence, Italy, 14 May 2004

A.M. van den BergDe oorsprong van de elementenBessensap, Amsterdam, the Netherlands, 18 May 2004

R.J. de MeijerOpsporen van landmijnenBessensap, Amsterdam, the Netherlands, 18 May 2004

H.W. WilschutHet heelal bestuderen met enkele atomenBessensap, Amsterdam, the Netherlands, 18 May 2004

C.J.G. OnderwaterMuon dipole moments: past, present and futureInstitute Laue-Langevin, Grenoble, France, 19 May2004

M.N. HarakehResearch at AGOR: 1996-2004Institut de Physique Nucleaire, Orsay, France, 28 May2004

S. BrandenburgAGOR ten years laterInstitut de Physique Nucleaire, Orsay, France, 28 May2004

D. BodewitsProbing space weather with cometary X-Ray and FUVemissionSRON Colloquium, Utrecht, the Netherlands, 9 June2004

R. HoekstraAtom trap trace analysis or the search for a needle in10.000 haystacksColloquium University of Amsterdam, the Netherlands,

100

15 June 2004

H.W. WilschutUsing radioactive isotopes to search for time reversalviolationSUNY at Stony Brook NY, USA, 16 August 2004

R.J. de MeijerEarth AntiNeutrino TomograpHyPresentatie bezoek Minister President Ys, den Haag,the Netherlands, 2 September 2004

S. HoekstraAtom trap trace analysis: searching for a needle in10.000 haystacksSeminar, European Laboratory for Non-linear Spec-troscopy, Florence, Italy, 12 September 2004

A.M. van den BergFrom nuclear to particle astrophysicsKapteyn Institute, Rijksuniversiteit Groningen, TheNetherlands, 13 September 2004

R.J. de MeijerEarth AntiNeutrino TomograpHyPresentatie TCNN, Groningen, the Netherlands, 30September 2004

H.J.WortcheEarth AntiNeutrino TomograpHy “nuts and bolts”Presentatie TCNN, Groningen, the Netherlands, 30September 2004

P. DendoovenRIASH: Radioactive ions and atoms in superfluid he-liumDepartment of Physics, University of Bielefeld, Ger-many, 5 October 2004

O. ScholtenPhoto-induced strangeness production off the nucleonHelsinki Institute of Physics, Finland, 7 October 2004

S. HoekstraAtom trap trace analysis: searching for a needle in10.000 haystacksSeminar, IKS Leuven, Belgium, 14 October 2004

D. Bodewits, R. MorgensternKometen: belicht door elektronvangstprocessenJongerejaarscolloquium Natuurkunde RuG, Gronin-gen, the Netherlands, 21 October 2004

R.J. de MeijerAntineutrinos to explore Terra incognitaColloquium Physics Department Westfalische Wil-helms Universitat Munster, Germany, 25 October 2004

S. BrandenburgTen years AGOR: balance and outlook

Research Center for Nuclear Physics, Osaka, Japan, 27October 2004

C.J.G. OnderwaterThe deuteron EDMUniversity of Sussex, Falmer, England, 27 October 2004

N. Kalantar-NayestanakiSearch for three-body force effects in proton-deuteronscatteringUniversity of Tehran, Iran, 6 November 2004

E.R. van der GraafEarth AntineutRino TomograpHy (EARTH). Op zoeknaar de warmtebronnen van de AardeStudiemiddag SBE RU Groningen, the Netherlands 16November 2004

L. WillmannKalte Atome, Radioaktivitat und fundamentale Sym-metrienKolloquium, Institut fur angewante Physik, Bonn Uni-versity, Germany, 16 November 2004

K. JungmannDer Atomkern als LaboratoriumTechnische Universitat Darmstadt, Germany, 19November 2004

S. HoekstraAtom trap trace analysis of 41CaSeminar, Frits-Haber Institut der Max-PlanckGesellschaft, Berlin, Germany, 3 December 2004

F.W.N. de Boer, T.J. Ketel, J. van KlinkenAnomalous internal pairconversion as a sign for elusivelight neutral particlesColloquium, NIKHEF Amsterdam, the Netherlands, 3December 2004

S. HoekstraAtom trap trace analysis of 41CaSeminar, Institute for Experimental Physics, InnsbruckUniversity, Austria, 7 December 2004

K. JungmannDer Atomkern als Laboratorium: Fundamentale Sym-metrien und WechselwirkungenWestfalischen Wilhelms-Universitat Munster, Ger-many, 8 December 2004

R.J. de MeijerLiving on a giant stoveColloquium iThemba Labs, South Africa, 14 December2004

R.J. de MeijerAntineutrinos: from here to eternity (De profundis adastra)ASTRON, Dwingeloo, the Netherlands, 16 December

101

2004

A.M. van den Berg

Neutrino detection in salt domes under LOFAR

ASTRON, Dwingeloo, the Netherlands, 16 December

2004

102

Chapter 10

Personnel

103

10.1 Scientific staff

Senior research scientists

Dr. W.K. van Asselt (until 1 December)Dr. J.C.S. BacelarDr. ir. J.P.M. BeijersDr. A.M. van den BergDr. G.P. BergDr. S. BrandenburgDr. P.G. DendoovenDr. A.E.L. Dieperink (until 1 March)Prof. Dr. S. Gales1

Dr. E.R. van der GraafProf. dr. M.N. Harakeh (director)Prof. dr. ir. R. HoekstraDr. M.A. HofsteeProf. dr. K.P. JungmannProf. dr. N. Kalantar-Nayestanaki

Prof. dr. H. LohnerProf. dr. R.J. de MeijerDr. J.G. MesschendorpProf. dr. R. MorgensternDr. C.J.G. OnderwaterDr. R.W. OstendorfDr. T.A. Schlatholter2

Dr. O. ScholtenProf. dr. G. van der Steenhoven3

Prof. dr. R.G.E. TimmermansDr. S.Y. van der Werf (until 1 March)Dr. L. WillmannProf. dr. H.W.E.M. WilschutDr. H.J. Wortche

Post-docs and graduate students

Drs. F. Alvarado Chacon (since 1 February)Drs. H.R. Amir AhmadiDrs. D. BodewitsDrs. R.J.J. CastelijnsDrs. S. De (since 19 July)Drs. G. ErkolDrs. M. Eslamikalantari (since 6 December)Drs. E.D. van GarderenDr. K. Gloos (since 15 December)Drs. A.V. de GrootDrs. V.G. Hasan (since 1 September)Drs. S. HoekstraDrs. S.I.E. de Jong (until 1 October)Drs. S. KnoopDr. C.P. LiuDrs. M. Mahjour Shafiei (until 1 September)Drs. P.P. MalekaDrs. H. Mardanpour Mollalar

Drs. A. MaticDr. M. MaucecDrs. A.A. Mehmandoost (until 1 July)Drs. A.K. Mollema (since 1 October)Dr. B. Mukherjee (until 6 May)Dr. H.G. Ott (since 1 November)Drs. S. Purushothaman (since 1 June)Drs. I. RadulescuDr. C.E. RigolletDr. A.M. Robin (since 1 August)Drs. A. RogachevskiyDr. M. Sanchez-Vega (until 1 June)Drs. S.V. ShendeDrs. M. SohaniDrs. E.K. TraykovDrs. M. UnipanDrs. A.S. Usov

Undergraduate students

M. BellosJ. BrouwerI. DenijsA. Deuzeman

A. HendrickxA. MolE. PolakF. Rusydi

1director IPN Orsay; extraordinary professor at Rijksuniversiteit Groningen2fellow of the KNAW (Royal Dutch Academy of Sciences)3senior research scientist at NIKHEF; professor by special appointment at the Rijksuniversiteit Groningen

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M. van VeenhuizenC. van der VegteR. te VeldeJ. Wagenaar

J.W. MosseltT. van der PloegE. Wessels

Emeritus guests

Ir. O.C. DermoisDr. A.E.L. DieperinkDr. A.G. DrentjeDr. J. van Klinken

Prof. dr. R.H. SiemssenDr. S.Y. van der Werf (from 1 March)Prof. dr. A. van der Woude

Visiting foreign scientists (for at least one month)

Prof. dr. C.L. Korpa, Janus Pannonius University, Pecs, HungaryProf. dr. M. Urin, Moscow Engineering Physics Institute (State University), Moscow, Russia

10.2 Technical and administrative staff

Cyclotron operation, cryogenics and cooling-techniques

R.M.S. Akollo4

D.W. BakkerM.O. Bleeker5

M. Bruining5

A. KroonJ. Mekkering6

H. PostJ.G. Siebring5

R. Terol5

R. Tjoelker5

Ing. S. van der VeenJ.N. de Vries7

Ing. N.J. van WiefferenR.H.L. van Wooning5

IT group

Ing. R.D. AlkemaIr. H.E. AssenIng. F.I.H. BarzangyDrs. M.J. van GelderDr. P.A. Kroon

F. SporrelJ.C. van der WeeleDr. F. Zwarts

Research technicians

Ing. G.H.P. EbberinkIng. I.H.J. FormanoyIng. H. FraiquinIng. L. Huisman

Ing. H.H. KiewietIng. H.R. KremersIng. J. MulderF. Rengers5

4for 50%; works also in the Mechanical department and vacuum techniques group5for 50%; works also in the Electronics and electrotechnical group6for 50%; provides other technical support7for 50%; works also in the Research technicians group

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J. Sijbring6

H.J. Timersma4

J.N. de Vries8

Electronics and electrotechnical groups

M.O. BleekerM. Bruining 8

D. DamstraIng. H.A.P. van der DuinH. Ebbinge (until 1 September)A. FelzelIng. M.A. HevingaIng. D. KamphuisH. KooiIng. G. van der KrukT. W. Nijboer

F. Rengers7

J.G. Siebring8

Ing. M. StokroosB.D. TaenzerR. Terol8

R. Tjoelker8

Ing. J. VorenholtP. WieringaR.H.L. van Wooning8

Mechanical department and vacuum techniques

R.M.S. Akollo4

Ing. R. BergsmaH. DostIng. S.J.N. DuinisveldR.J. DusselH.F. GorterE. LatumaleaW.W.P. OlthuisG.J. Sa

L. SlatiusI. SmidJ. SmidIng. H.A.J. SmitD.J.M. TilmanH.J. TimersmaJ.H.J. Wieringa

Other technical support

R. ten HaveIng. D. KamphuisJ. Mekkering4

J. Sijbring5

Apprentices (for at least three months)

G. Mul (since 18 October)

Administrative department

Drs. L.A.M. HeimanDr. M. KoopmansH.J. Landstra9

S.M. de MeijerA.D. PetitiauxC. Smit

R.E. SpringerR.J. Steeman-PoelmanG. van der Tuin-VenemaM.W. van der Wijk-Ruiter

8for 50%; works also in the cyclotron operation, cryogenics and cooling-techniques group9works also in the Personnel department

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Personnel department

H.J. Landstra10

Drs. H.E. van der MeerM. van der Veen-Holman (until 1 March)

A.M. van der Woude

Reception and cafetaria

A. AikemaH.K. EleniusG.M.W. de GraafP. Mekkes

T. KeimpemaW. Timmerman

10works also in the Administrative department

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