EWON Workshop, Prague, 10-12 May 2007 EWON Workshop, Prague, 10-12 May 2007 GOSIA GOSIA as a tool for as a tool for COULEX on exotic COULEX on exotic beams beams Katarzyna Wrzosek Katarzyna Wrzosek Heavy Ion Laboratory Heavy Ion Laboratory Warsaw University Warsaw University
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EWON Workshop, Prague, 10-12 May 2007 GOSIA as a tool for COULEX on exotic beams Katarzyna Wrzosek Heavy Ion Laboratory Warsaw University.
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EWON Workshop, Prague, 10-12 May 2007 EWON Workshop, Prague, 10-12 May 2007
GOSIA GOSIA as a tool for COULEX as a tool for COULEX
on exotic beamson exotic beamsKatarzyna WrzosekKatarzyna Wrzosek
Heavy Ion Laboratory Heavy Ion Laboratory
Warsaw UniversityWarsaw University
EWON Workshop, Prague, 10-12 May 2007 EWON Workshop, Prague, 10-12 May 2007
LOW - ENERGY COULOMB LOW - ENERGY COULOMB EXCITATION:EXCITATION:
Well-established method to study collective Well-established method to study collective excitations in nuclei.excitations in nuclei.
Purely electromagnetic Purely electromagnetic the only nuclear the only nuclear properties involved are the properties involved are the matrix elementsmatrix elements of the electromagnetic multipole moments.of the electromagnetic multipole moments.
EWON Workshop, Prague, 10-12 May 2007 EWON Workshop, Prague, 10-12 May 2007
Gamma ray spectrometerGamma ray spectrometer EXOGAM – up to 11 segmented Ge clovers (90 and 135)
Particle detectorCD-detector - annular, highly segmented double silicon strip detector (DSSD)covered angles: 23,8-54,5 in the LAB ≡ 24-145 in the C.M. frame
208Pb
EWON Workshop, Prague, 10-12 May 2007 EWON Workshop, Prague, 10-12 May 2007
EWON Workshop, Prague, 10-12 May 2007 EWON Workshop, Prague, 10-12 May 2007
GOSIAGOSIA GOSIA is a Rochester – Warsaw semiclassical coupled-GOSIA is a Rochester – Warsaw semiclassical coupled-
channel Coulomb excitation least-squares search code.channel Coulomb excitation least-squares search code. Developed in early eighties by Developed in early eighties by
T. Czosnyka,T. Czosnyka, D. Cline, C.Y.Wu D. Cline, C.Y.Wuand continuously upgraded to fulfill requirements of new and continuously upgraded to fulfill requirements of new experiments.experiments.
Used extensively for Coulomb excitation studies of a wide Used extensively for Coulomb excitation studies of a wide range of nuclei.range of nuclei.
Typical use of GOSIA:Typical use of GOSIA:1.1. Fitting of the matrix elements to the experimental data.Fitting of the matrix elements to the experimental data.2.2. Simulation of the experiments:Simulation of the experiments:
to predict which to predict which - ray will be observed - ray will be observedto check to what extent the observation will depend on to check to what extent the observation will depend on individual matrix elements.individual matrix elements.
EWON Workshop, Prague, 10-12 May 2007 EWON Workshop, Prague, 10-12 May 2007
AN EXAMPLE:AN EXAMPLE:COULOMB EXCITATION OF COULOMB EXCITATION OF 74,7674,76Kr @ GANILKr @ GANIL
Coulomb excitation is the only method that can Coulomb excitation is the only method that can directly distinguish between different shapes of the directly distinguish between different shapes of the nucleus nucleus ideally suited to verify the shape coexistence ideally suited to verify the shape coexistence scenario in the Kr isotopes.scenario in the Kr isotopes.
Shape parameters of the two lowest 0Shape parameters of the two lowest 0+ + states in states in 7474Kr Kr and and 7676Kr nuclei were inferred from coulomb Kr nuclei were inferred from coulomb excitation data.excitation data.
The Coulomb excitation analysis were performed The Coulomb excitation analysis were performed using the last squares fitting code GOSIA.using the last squares fitting code GOSIA.
EWON Workshop, Prague, 10-12 May 2007 EWON Workshop, Prague, 10-12 May 2007
EWON Workshop, Prague, 10-12 May 2007 EWON Workshop, Prague, 10-12 May 2007
RESULTSRESULTS
EWON Workshop, Prague, 10-12 May 2007 EWON Workshop, Prague, 10-12 May 2007
QUADRUPOLE ROTATIONAL QUADRUPOLE ROTATIONAL
INVARIANTINVARIANT SUM RULES SUM RULES model independent description of the nuclear shapemodel independent description of the nuclear shape
is based on a fact, that scalar products of E2 is based on a fact, that scalar products of E2 operators are operators are rotational invariantsrotational invariants. . Operator products may be expressed using the Operator products may be expressed using the intermediate state expansion formula:intermediate state expansion formula:
EWON Workshop, Prague, 10-12 May 2007 EWON Workshop, Prague, 10-12 May 2007
QUADRUPOLE ROTATIONAL INVARIANTQUADRUPOLE ROTATIONAL INVARIANT SUM RULES SUM RULES
model independent description of the nuclear shapemodel independent description of the nuclear shape
To get information on triaxiality the higher order To get information on triaxiality the higher order invariant is neededinvariant is needed::
EWON Workshop, Prague, 10-12 May 2007 EWON Workshop, Prague, 10-12 May 2007
RESULTSRESULTS The deformation of the 0The deformation of the 0++
11 is very similar in is very similar in 7474Kr and Kr and 7676Kr. Kr.
Triaxiality parameterTriaxiality parameter: : the ground state of the ground state of 7676Kr is Kr is prolateprolate, while the 0, while the 0++
22 state has an state has an triaxialtriaxial shape.shape.
Both, the ground state and the 0Both, the ground state and the 0++22 state of state of 7474Kr are Kr are triaxialtriaxial,, but with but with
different different parameter. parameter.
EWON Workshop, Prague, 10-12 May 2007 EWON Workshop, Prague, 10-12 May 2007
Collaboration of Collaboration of 74,7674,76Kr Project Kr Project CEA Saclay, FranceCEA Saclay, France
Oliver Lodge Lab., Liverpool, UKC.Andreoiu P.A.ButlerR.-D.HerzbergD.G.JenkinsG.D.Jones
Univ. Of Surrey, Guildford, UKW.N.CatfordC.Timis
GSI, Darmstadt, GermanyF.BeckerJ.Gerl
NBI, Copenhagen, DenmarkG.Sleten
EWON Workshop, Prague, 10-12 May 2007 EWON Workshop, Prague, 10-12 May 2007
List of the experiments List of the experiments where GOSIA was recently usedwhere GOSIA was recently used
ISOLDE (MINIBALL), CERNISOLDE (MINIBALL), CERN:: J. Cederkall – J. Cederkall – 108108Sn, Sn, 110110SnSn J. Iwanicki - J. Iwanicki - 8888Kr, Kr, 9292KrKr A. Hurst - A. Hurst - 7070SeSe I. Stefanescu – I. Stefanescu – 6868Cu, Cu, 7070CuCu J. Van de Walle – J. Van de Walle – 7474ZnZn GANIL (EXOGAM), FRANCEGANIL (EXOGAM), FRANCE:: E. Bouchez – E. Bouchez – 7676KrKr E. Clement – E. Clement – 7474KrKr M. Zielińska – M. Zielińska – 4444ArArJYVASKYLA, FINLANDJYVASKYLA, FINLAND F. Becker – F. Becker – 7878KrKrJAEA, TOKAI, JAPANJAEA, TOKAI, JAPAN:: M. Koizumi - M. Koizumi - 6666Zn, Zn, 6868ZnZn T. Hayakawa – T. Hayakawa – 7878SeSe A. Osa - A. Osa - 8484KrKr Y. Toh – Y. Toh – 7070GeGe M. Zielińska – M. Zielińska – 9696MoMoANL (Gammasphere), USAANL (Gammasphere), USA A.Hayes – A.Hayes – 178178HfHf
Next experimentsNext experiments
ISOLDE (MINIBALL), CERNISOLDE (MINIBALL), CERN:: E. Clement – E. Clement – 9696Sr Sr
(Jul 2007)(Jul 2007) P.Butler, P. Van Duppen - P.Butler, P. Van Duppen - 182,184182,184Hg Hg
(Aug 2007)(Aug 2007)
JRA6JRA6INTAGINTAG
EWON Workshop, Prague, 10-12 May 2007 EWON Workshop, Prague, 10-12 May 2007
Warsaw Coulomb Excitation GroupWarsaw Coulomb Excitation Group@ Heavy Ion Laboratory, Warsaw Univ.@ Heavy Ion Laboratory, Warsaw Univ.
Tomasz CzosnykaTomasz Czosnyka Julian SrebrnyJulian Srebrny Jędrzej IwanickiJędrzej Iwanicki Paweł NapiorkowskiPaweł Napiorkowski Magdalena Zielińska (CEA Saclay)Magdalena Zielińska (CEA Saclay) Katarzyna WrzosekKatarzyna Wrzosek Katarzyna Hadyńska (UAM, Poznań)Katarzyna Hadyńska (UAM, Poznań) Daniel Piętak (PW, Warsaw)Daniel Piętak (PW, Warsaw)
EWON Workshop, Prague, 10-12 May 2007 EWON Workshop, Prague, 10-12 May 2007