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Regione Piemonte - Bando Convergingtechnologies 2007 - Piedmont
RegionConverging technologies call 2007
neutron and x-ray tomography and imaging for cultural
heritage
ACRONYM: neuARTSECTOR: Nanotechnology - new materials -
ICTABSTRACT: Modern Cultural Heritage restoration techniques and in
general the need ofa deep understanding of the fine structure of
objects of cultural significance requirepowerful and complementary
analysis, and have a particular relevance in our region sincethe
foundation of the Centro Conservazione e Restauro “La Venaria
Reale”. This centrerepresents a relevant cultural enterprise in our
region, being both a restoration and aformation centre for cultural
heritage restorers at university level. It is certainly strategic
forCCR development to promote collaborations with other research
institutes, universities,and private companies of Piemonte in the
framework of cultural heritage object analysisand description. We
focus in the present proposal on the importance of computed
tomography andimaging as invaluable tools for the description and
understanding, prior restoration, ofcultural heritage objects, not
only with the more conventional X-ray tomography, but alsousing
neutron computed tomography (CT) and imaging. The use of neutrons
in the cultural heritage field has received considerable attention
in thepast years. Neutrons are particularly suited in art objects
analysis and imaging due to theircapability to penetrate thick
layers of materials, and they are very interesting when used
inconjunction with X-ray imaging, since the absorption of photons
and neutrons are verydifferent for various materials (metals for
instance are almost neutron transparent contraryto photons, while
H2 rich materials are opaque to neutrons). Neutron
computedtomography can be obtained, in analogy with X-ray CT, by
measuring the attenuation of aneutron beam passing through the
sample to be analyzed. By rotating the object exposedto the neutron
beam and by using custom image reconstruction algorithms, it is
possibleto form 3D virtual maps of the object. The similarity in
the two imaging approaches makespossible the planning of a CT
device which can be used for both type of analysis. Cold and
thermal neutron sources are generally nuclear reactors designed for
researchpurposes, like the two Italian plants of University of
Pavia and ENEA-Roma. In the presentproposal however we would use a
small and compact high intensity Deuterium-Deuteriumfusion source
with a full solid angle integrated fluence of up to 10**12n/sec
that will beinstalled in the existing bunker of the Experimental
Physics Department of the TorinoUniversity. The involved groups
have a ten year experience in these kinds of neutronsources, in
design and construction of moderators to obtain thermal neutrons
and inneutron detection. In parallel to neutron and X-ray computed
tomography, Prompt GammaActivation Analysis will be exploited,
using resonance absorption properties of cold
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Title
GENERAL INFORMATIONS
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neutrons. Many elements, commonly found in cultural heritage
objects, have neutronabsorption resonance properties, and their
cross sections are known in detail. This allowsrelative abundance
determination of neutron sensitive elements, which is often
essentialfor traceability of archaeological artifacts and artistic
object components. The project will be completed building a 2D x-y
plotter for high resolution X-rayradiography of large scale
paintings (up to 3x4m) to be installed in the CentroConservazione e
Restauro “La Venaria Reale”. This device will furnish the Venaria
Centrewith an imaging instrument of unprecedented potential for
applications, both for therestoration and the study of ancient
paintings. The present proposal is the result of the synergic
concentration of efforts of the TorinoINFN and Experimental Physics
Department groups that have accumulated aconsiderable experience in
neutron physics, material characterization using low energy X-ray
and particle beam, high energy physics large scale experiments and
particle detectorsdesign and assembly.DURATION (months):
36TECHNICAL SCIENTIFIC OBJECTIVES: The main goal of this project is
the constructionof a combined system for neutron and X-ray computed
tomography and imaging, focusedon Cultural Heritage analysis in
collaboration with the Centro Conservazione e Restauro“La Venaria
Reale”. To our knowledge this will be the first combined system
devoted to thiskind of application in Italy. Neutron Tomography is
a useful technique for testing objects of artistic
andarchaeological interest, given the fact that thermal neutrons
are non invasive and canpenetrate thick layers of the sample. The
unique possibility to operate a neutron source isprovided by the
presence in the underground area of the Department of Physics of
theUniversity of Torino of a dedicated, certified shielded bunker,
where in former times the“Turin Syncrotron” was hosted. Present
technology allows the construction of compact highintensity neutron
sources, based on RF-driven ion source impinging few hundreds
KeVaccelerated D plasma on a D o T target, where neutrons are
produced by fusion process.The limited size of the neutron source
makes feasible the planning of a in-housetomographic device which,
having the ability to rotate the target and displace the
detectorindependently, allows neutron tomography on samples of
unprecedented dimensions(when compared to fixed neutron sources
deriving from nuclear reactors). As a complement to neutron
computed tomography (CT) we plan to develop elementanalysis
techniques like Prompt Gamma Activation Analysis (PGAA), a
technique whichallows the detection of the elemental distribution
in the sample. The neutron CT system will be set in parallel to a
X-ray CT system, allowingcomplementary imaging of the same sample
and thus enriching the analysis potential ofthe project. The
experience of the groups involved in this proposal is crucial in
the knowledge and useof neutron and X-ray sources and detectors.
These type of detectors are developments ofHigh Energy Physics
experimental programs, and research efforts will be invested
indetector optimization according to the required performance. The
proponent groups haveexperience in gas detector and silicon
detector systems, detector families widely used inneutron and X-ray
imaging. In particular a group participating to the project has
developeda detecting system based on silicon microstrip detectors
and single-photon countingelectronics optimized for dual-energy
X-ray imaging. This system has been successfullyused both for
medical imaging tests and for mapping the distribution of
particular chemicalelements (e.g Zn, Cd) in art paintings. In
parallel to detector know-how, the INFN Torino group, with its
staff of engineers andtechnicians, will allow a full custom and
optimized integration of the detection system in afully numerical
controlled computed tomography device, designed from scratch to be
usedboth for neutron and X-ray imaging, and another dedicated tool
for 2D X-ray imaging oflarge scale art paintings (3x5m) to be
installed in the Centro di Conservazione e Restauro
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di Venaria Reale. This device will provide the Venaria Centre
with an imaging instrumentof unprecedented potential both for the
restoration and the study of ancient paintings.STATE OF THE ART:
Tomography allows investigations of the microscopic innerstructure
of large samples; it is based on the measurement of the attenuation
of aradiation beam passing through an object and is done by taking
images at differentorientations of the sample and reconstructing
off-line all data in a virtual 3D object. Many kinds of particles
and radiations can be used to obtain important information aboutthe
structure, density, composition, etc. of the analyzed objects, but
two complementarymethods are X-ray and neutron tomography, since
the absorption of photons andneutrons are very different for
various materials: metals for instance are almost
neutrontransparent (as opposed to photons), while H2 rich materials
are opaque to neutrons. Since X-ray can easily penetrate through
centimeters of light materials (liquids andorganic materials), they
are utilized in many fields including medicine, cultural
heritage,and industrial applications. In cultural heritage X-ray CT
and imaging is mainly used in thestudy of textile, argillaceous and
ligneous artworks, but also small metal and stone piecesare
analyzed; the importance of this diagnostic tool can be understood
for example in theligneous artworks analysis were X-ray CT can
provide information about cracks, worm-eaten areas, woods density,
annual rings, nails, etc. At present, small X-ray tubes up to 450
KeV and Linac up to few tens of MeV are used assources; the minimum
spatial resolution achievable is about 1 micron. In Italy
someindustries (for examples Fiat Avio) have their own system, but
there is no researchinstitution that provides high-level services
as in other countries (e.g. EMPA, Switzerland). Contrary to the
photon case, a neutron beam can transmit through centimeters of
metalbut it is easily attenuated by small amounts of light elements
like hydrogen, boron andlithium. For this reason neutron tomography
is an unique tool for non-destructive testingwith applications in
cultural heritage analysis, industry, material science and various
otherfields. The investigation of moisture and corrosion, the
detection of explosives andadhesive connections and the inspection
of defects in nuclear fuel or in thick metallicsamples are examples
where neutron can be utilized favorably. Neutron tomography is
obtained using beams of thermal or cold neutron from
nuclearreactors and so must be considered as stationary. In fact,
until now, only reactors cangive fluxes with sufficient intensity
for a tomography (between 10**5 and 10**9 n/cm**2 s),but the beam
collimation allows to obtain a maximum beam area of 30x30 cm and so
toanalyze only small objects. In Italy there are only two of these
reactors located at theUniversity of Pavia and ENEA-Roma. In the
past years some small neutron generators have been developed (e.g.
in Berkeley),but until now they have only been used for medical
applications (BNCT). They are highintensity Deuterium-Deuterium
fusion sources with a full solid angle integrated fluence ofup to
10**12 n/sec. After moderation and collimation the obtained flux is
sufficient toproduce a neutron-image in few seconds. Using a last
generation CCD camera with2048x2048 pixels it takes about 4 s to
readout the entire array. The minimum spatialresolution achievable
is about 0.2mm, and it degrades linearly with the distance
betweenthe sample and the conversion screen. The best example of
currently existing activity in this field in Europe (Milano and
Romafrom Italy), is represented by the ANCIENT CHARM initiative,
which is the result of acollaboration between 10 universities,
research laboratories, and museum institutionsacross Europe, and is
now a EU funded ADVENTURE project, under the New andEmerging
Science and Technology (NEST) program of FP6. The central goal of
ANCIENTCHARM is to develop an imaging technique based on Neutron
Resonant Capturetogether with complementary neutron diffraction,
and transmission-based imagingtechniques.POTENTIAL IMPACT: The
present proposal would entail significant advances in thetechnical
and scientific know-how acquired by the research partners (INFN
Torino and the
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University of Torino) in a new field, i.e. non-destructive
characterization techniques forcultural heritage, opening up new
possibilities for national and international
scientificcollaborations, participation in international calls and
funding initiatives, and providing anenriched base for the existing
collaboration with the Centro di Conservazione e Restauro“La
Venaria Reale” for teaching and courses. Also, it would provide an
opportunity toreconvert highly-specialized INFN structures and
facilities to new tasks. For the industrial participants (SEPA SpA
Torino and NEKHEM Srl Torino), the projectcould bring considerable
advantages related to the acquisition of new knowledge
andexpertise, expanding the working area of interest from
scintillation detectors forradioactivity measurements in transit
goods to that of neutron sources and detectors forvarious
applications (SEPA), and from imaging for medical applications to
imaging in thefield of cultural heritage (NEKHEM). The neutron
radiography technology to be developedin the project can indeed be
easily applied both in the characterization of cultural
heritageartefacts as in the verification of structural integrity of
large scale parts used in varioussectors of industry. Thus, the
project could possibly open up new possibilities and marketportions
for SEPA and NEKHEM in Piemonte and abroad. The main objective of
the project is however to provide the Centro di Conservazione
eRestauro di Venaria Reale with technology, structures and know-how
in the field of X-rayand neutron radiography (currently available
only in the ENEA-Roma plant), thus possiblyrealizing the ambitious
goal of allowing the Venaria Centre to compete with the two
mostimportant centres for cultural heritage conservation in Italy,
namely Rome and Florence.The impact for the Venaria Centre, for the
city of Venaria and for the Region of Piemontewould thus be
considerable in terms of visibility and prestige. Also, the new
techniquesdeveloped in the project could be applied to characterize
the state of conservation ofmany medium or large scale artefacts
currently residing in the Museums of Torino andPiemonte.DESCRIPTION
OF THE RESOURCES: The Istituto Nazionale di Fisica
Nucleare,operates in close collaboration with departments of Fisica
of the University of Torino,sharing infrastructures, manpower,
laboratories and knowledge. For this reason bothinstitutes are to
be considered as proponents and act in full coordination. The
Sezione di Torino of Istituto Nazionale di Fisica Nucleare, is
organized in researchstaff members (physicists and engineers), who
actively work in experimental activitiescentrally managed by
national scientific committees of the institute, and local
serviceswhich grant administrative and technical support. The
technical support is organized inspecialized divisions, with
permanent technical staff. In Torino INFN can support
activitiesthrough its electronic laboratory, where electronics and
integrated electronic projects canbe fully developed, through the
mechanical workshop, a 3000 m**2 atelier, wheremechanical engineers
and designers can develop projects and produce executabledrawings
of objects which can be built in the workshop by dedicated
personnel working onnumerical controlled milling machines of
various types and dimensions, and finally by acomputing centre,
which grants full supports for operating local servers and
complexcomputing farms designed, assembled and operated to meet the
important computationalrequirements of the experimental groups. The
present project will heavily make use of the Torino INFN resources
both in terms ofthe use of the infrastructures related to the
described laboratories, and in terms ofmanpower provided by
technical staff of the administration, electronics, mechanical
andcomputing local services. In particular, a sophisticated large
scale, high precisionmotorized x-y gantry, designed and built by
INFN Torino for the construction of the muondetectors of the CMS
experiment at CERN (43 Drift Tubes chambers of 4,2x2,5m withmore
that 50000 readout channels), will be modified and adapted to be
operated as X-raysource and detector support for large area art
painting X-ray imaging. The dual X-raysilicon detector has also
been developed by INFN for the NA50 experiment and hasalready been
successfully used in art painting imaging.
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Moreover University of Torino will provide the laboratories,
with associated equipments,where the scientific apparatus will be
assembled and operated, and, mostly important, theshielded bunker
where all nuclear devices, the neutron source and the X-ray source
willbe operated in full conformity with the existing law. This area
is a unique structure thatwas used until 1986 for the "Turin
Synchrotron", a formerly pioneering electronaccelerator machine.
The area has been recently renovated and is available
forinstallation of a stationary nuclear device as, for instance, a
neutron source. University willalso be of crucial relevance in the
formation of students and fellows who will join thisproject. It
should be underlined that co-proponents of this project, already
active in thefield of neutron analysis, are also teaching
university courses in the Venaria Centre, bothin the Restoration
School and in the Corso di Laurea in Scienza e Tecnologia per i
BeniCulturali of the Science Faculty of the Torino
University.ORGANIZATION: The collaboration is formed by five
partners, one proponent (IstitutoNazionale di Fisica Nucleare Sez.
di Torino) and one additional proponent (Universita’ diTorino), two
co-proponents (SEPA S.p.A. and NEKHEM S.r.l.) and one additional
subject(Centro Conservazione e Restauro “La Venarla Reale”). The
project, planned over 3 yearsactivity, is organized in 10 Work
Packages. The weight of each partner in each WP ismodulated over
the expertise and know how which will be invested. The Dipartimento
diFisica Sperimentale of University of Torino will have a leading
role in WP1 (neutronsource) and WP3 (neutron detector), given the
fact that the group has very good anddocumented experience in these
fields. INFN, thanks to the experience on designconstruction and
commissioning of large apparatuses and related electronics,
willcoordinate WP6 (mechanical system for X-ray and neutron
Computed Tomography), WP8(2D Art Painting Radiography) WP9
(K-Threshold Art Painting Imaging), and WP10 (WPmanagement). WP2
(Design and manufacturing of thermal/cold column) and WP5
(X-RayTomography) will have important contributions from both INFN
and University of Torino.Finally WP4 will be covered by
co-proponent SEPA S.p.A. (Photon Gamma ActivationAnalysis Detection
and Neutron Resonant Capture Analysis), a firm with good expertise
inphoton detector applications, while NEKHEM S.r.l., a computing
SME with skills inmedical imaging algorithms development, will take
responsibility and organize WP7 (X-Ray and neutron tomography and
imaging. Centro Conservazione e Restauro “La Venaria Reale”, is the
final user of all project’s WP’sand directly participates to
WP3,5,8,9. It’s activity will be fundamental in giving feedbackand
validation to all CT imaging instruments and algorithms developed.
The overall project organization, will be managed through WP10,
which will cover generalcoordination tasks and will constantly
monitor progresses of the activities of the WP’s,ensuring that the
project will meet its objectives within budget and scheduled
timescales.This WP will routinely make reports both to funding and
collaborating agencies and willdrive dissemination initiatives. All
administrative work will be managed and controlledwithin this WP.
The consortium will be coordinated by the project manager with
regular meetings and adedicated web site will be used to archive
all informations and documents shared by allpartners.DISSEMINATION:
The collaboration with the Centro Conservazione e Restauro
"LaVenaria Reale" will play a central role in the dissemination of
the scientific results ofthe present project. We expect that the
analysis of artistic objects of different types, bothin terms of
tomography and radiography inspections and in terms of analysis of
thematerials, will allow a deeper understanding of the artistic
samples. This will turn either ineasier and better restoration when
needed, or in traceability or authentication of art
objectcomponents or archaeological sample. The dissemination of the
results of the analysis ofartistic objects will therefore proceed
through parallel streams. The Centro Conservazionee Restauro "La
Venaria Reale" will provide the best visibility to the project.From
the appearing of first results to the end of the project CCR will
organize and
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patronize meetings and workshops about diagnostic and scientific
aspects involved,paying always the right attention to preserve any
information connected to eventualpatents. Relevant events will be
also widely communicated to press agencies. Starting from the
important flux and presence of artistic samples in its
restorationlaboratories, CCR could easily organize workshops
focused on manufacts of particularartistic and historical
relevance. In parallel to this, scientific results coming from the
research of the proponents will bepresented in national and
international conferences and workshops, where theachievements in
the neutron and X-ray tomography of cultural heritage objects will
bepresented. Dissemination will also go through publication of
scientific results oninternational reviews. Publication of
scientific results will be strongly encouraged andpursued during
the full activity of the project, but all dissemination initiatives
will always bepreviously discussed within the full group
(proponents, co-proponents and adjunctivesubjects). As for CCR care
will be taken in preserving informations related to
potentialpatents. An essential tool to maximize internal
communication between the partners (passwordprotected) and
information to external world will be the creation and maintaining
of a website dedicated to this project. Within the web site we will
create a database to be used asa general repository of all actions
taken by any of the partners in the diffusion of theresults of the
project (thus including presentations to workshops and
conferences,published articles and posters, press releases, and
patents). The group of partners will also enhance dissemination of
general informations on theproject also outside the cultural
heritage and scientific communities, since we expect thatthe
technology described in this project will have important potential
applications also inother fields of relevant importance in Piedmont
territory. This will be done not only throughthe web site, but also
by directly investigating possible applications in other fields,
throughactive analysis of reviews and conference proceedings and
direct communication withexternal subjects dealing with
applications possibly related to our analysis
capabilities.DIFFUSION OF THE RESULTS: As specified above, the main
aim of the project is toexploit existing know-how and resources
from the INFN and University research partnersto provide the
Venaria Conservation and Restoration Centre with innovative
facilities foreffective characterization of cultural heritage
artefacts, with the support of industrialresearch partners who will
be involved in the development of the detecting and dataprocessing
stages. Therefore, the interest in the exploitation and diffusion
of the projectresults differs for the various partners: INFN and
UniTo have interest in communicatingthe scientifically original
results of the project in journal publications and
conferencecontributions; the Industrial partners have interest in
acquiring the know-how for thedescribed characterization techniques
for future exploitation in consulting services orapplications in
other fields, possibly leading to patents for specific instruments
ortechniques developed in the course of the project; the Venaria
Centre has mainly interestin acting as end-user in this case,
acquiring innovative technology and expertise for theuse of an
additional characterization technique for cultural heritage
objects, thus reachinga prominent position among its competitors.
Therefore, the participants have subscribed arather general
preliminary agreement on Intellectual Property Rights (IPR),
basicallystating that any original knowledge emerging from the
project will be attributed to allparticipants involved in its
acquisition and circulated exclusively among them, with
thepossibility of publishing scientific results and/or exploiting
technical innovations forcommercial purposes, e.g. patents. There
is also the opportunity of involving venturecapital at a later
stage, e.g. in a continuation of the project, possibly leading to a
Startupcompany exploiting the know-how and specialist
instrumentation developed in the project.In this case, the IPR
settlement would be modified accordingly, with specific
agreementsbetween the participants.ISSUES ETHICS: We do not
envisage ethical aspects to be relevant to the present
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project.ATS (more than one coproponent): YesASSOCIATED KEYWORDS:
4.6.12 Neutron physics ,4.3.11.3 Software development,2.1.3.3 Art
works restoration ,2.1.3.2 Art works preservation ,4.3.1 3 D
modelling ,4.6.8.1Radiation physics ASSOCIATED ACTIVITY CODES: 3.4
New areas not covered in the specific programme,3.1.1 Long-term
interdisciplinary research into understanding phenomena,
masteringprocesses and developing research tools ,3.1.5
Applications in areas such as health andmedical systems, chemistry,
energy, optics, food and environment FREE KEYWORDS:
art,neutron,tomography,X-ray,digital-imagingFREE ACTIVITY CODES:
nuclear techniques applied to cultural heritageFINANCING TOTAL:
6529858FINANCING TOTAL PROPONENT: 3899748FINANCING TOTAL
COPROPONENT: 2007760
NUMBER: 1TITLE: Installation and characterization of neutron
generatorRESPONSIBLE: LORENZO VISCASTARTING MONTH: 1ENDING MONTH:
36OBJECTIVES: At present neutron tomography can be realized by
means of thermaland/or cold neutrons mainly produced by nuclear
reactor. The project proposes to use acompact neutron source
developed by the Plasma and Ion Source Technology Group atLawrence
Berkeley National Laboratory. This device is based on D-D fusion
reaction,producing 2.45 MeV neutrons. It can provide neutron flux
in excess of the current state ofthe art D-D neutron generators and
more than most commercial D-T neutron generators.It operates
without pre-loaded target or radioactive tritium gas. Safe and
reliable long-lifeoperation is typical feature of this D-D
generator. Because of the high neutron fluence produced by the
neutron source, great attention hasto be pointed on protection from
the ionising radiation produced. For this reason the D-Dsource will
be installed in the bunker located at the Experimental Physics
Dept. of TorinoUniversity. This facility was realized around 1960
to host a particle accelerator used fornuclear physics experiments
and it has been recently modified in such a way to besuitable for
installing new irradiation facilities. The D-D neutron generator is
based on a unique co-axial design, which maximizes thetarget area
in a compact outer dimensions of the generator. The dimensions
areapproximately 45 cm in diameter and 60 cm in height. The large
target area enables oneto operate at high beam power, with
efficient cooling thus yielding high neutron fluxes.The most
powerful prototype available from LBNL is designed to operate 300
mA ofdeuterium beam current at 160 kV of acceleration voltage. This
beam current andacceleration voltage yields a D-D neutron flux of
>10^11 s-1. In order to run the device a high vacuum has to be
reached inside the plasma chamber;then the deuterium gas is flowed
inside the chamber and plasma is generated by RF(13.56 MHz)
discharge method. The produced ions are subsequently diffused
toward theextraction apertures of the plasma chamber and
accelerated in the gap between theplasma generator and the target
cylinder. When ions are accelerated they impinge on a titanium
coated aluminum target, ions areimplanted in it to about 1 micro
meter depth. Due to the elevated temperature of the
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Work Package: Installation and characterization of neutron
generator
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implanted target area, the deuterium atoms diffuse in the metal
matrix. The maximumreaction efficiency is reached when these
diffused deuterium atoms are reacting with in-coming deuterium ions
at very close to the target surface. An electrostatic
secondaryelectron filter structure is employed between plasma
chamber and target in order to stopthe secondary electrons
accelerating back to the plasma generator, thus generatingexcess
heat in the plasma generator walls and lowering the available HV
power supplycurrent for the ion beam. An additional secondary
electron filter arrangement is made bypermanent magnets, located
into the aluminum target cylinder. A magnetic shieldingmade of
carbon steel is wrapped around the target to eliminate any stray
magnetic fieldstowards the target, that might lead to HV
spark-downs. The target cylinder-structure issupported by a Al2O3
cylinder, which functions also as a high voltage insulator. The aim
of this task is to optimise the functional parameters of the
neutron source in sucha way to maximize the neutron flux. In
particular the activity consist on: 1) investigation and
optimisation of the deuterium plasma generation; 2) study and
manufacturing of the cooling system; 3) optimisation of the vacuum
system; 4) monitoring of: functional parameters, material
characteristics, material stress underhigh neutron irradiation,
materials activation; 5) beam testing and installation and tests of
commercial beam monitoring system; 6) installation of interlock
systems both for radioprotection and instrumentation
safety.DESCRIPTION: 1) An important feature of the RF-induction
discharge is that it generateshigh fraction of atomic ion species
from molecular gases. Another feature of the RF-induction discharge
is its ability to generate high plasma. An RF-matching network is
usedto match the plasma and antenna impedance to the output
impedance of the RF-amplifierand co-axial transmission line. One of
the activity inside of this task is the optimization of the
matching network tomaximize the transferred power from the RF
generator to the antenna. Correct impedancematching allows to
obtain high density plasma for high extractable ion current
fromrelatively small discharge volume. Different tests about the
antenna life have to be taken on. This high flux generator is
aunique prototype and there are not so clear indications about the
antenna wear underhigh usage stress. 2) Titanium has the property
to form stable chemical compounds (metal hydrides) whencombined
with hydrogen or its isotopes while aluminium is characterized by a
lowdiffusivity for deuterium. During the first few minutes of
operation the target will be''loaded'' with deuterium atoms. During
this phase of operation the neutron yield isconstantly increasing.
When equilibrium condition is reached and the target is
saturatedthe neutron yield saturates to a level typical for the
current and voltage used. If the targettemperature increases to
much the equilibrium is lost and the neutron flux decreases. A
close loop cooling system has to be realized: deionising water has
to be cooled andtemperature controlled by a chiller before to reach
the target, the vacuum system, theantenna and the RF network.
Different tests about the link between the target cooling and the
neutron beam have to betaken on in such a way to determine the
correct temperature of the target to maintain astable neutron beam.
3) The vacuum system is based on a turbo molecular pump, backed by
a rotary vaneroughing pump. Without gas load the vacuum in the
target chamber will reach 10^-8 mbarlevel. Good vacuum level has to
be maintained during the deuterium gas injection insidethe plasma
chamber. Better vacuum condition supports the deuterium ion beam
inreaching the target. Tests about the level of both gas flow and
vacuum are needed to
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obtain high plasma density and good neutron beam performance.
Periodic checks of thevacuum will control possible leakages in the
system mainly due to gaskets damages. 4) It is necessary to realize
a cross checking monitoring system of different
functionalparameters (vacuum level, plasma density, target
temperature, cooling flow) to have acomplete control of the neutron
generator and to prevent possible risks derived fromfunctional
failures of the service apparatus. Periodic disassemblies of part
of the systemare necessary to asses possible components’ damages
and activation due to the highradiation stress level. 5)
Characterization of the beam is necessary because this kind of
neutron generator hasnever worked at so high emission rate. Neutron
spectra of the bare generator has to bemeasured for realising the
moderator column. This measured has to be taken on usingdifferent
methods to cover all the energy range. Neutron fluence has to be
measured infunction of voltage and current of the HV generator,
plasma density and targettemperature. After that correct commercial
beam monitoring system has to be bought,installed and tested. 6)
Italian regulations require some features for the use of neutron
source generating aneutron beam >10^7 n/s. Class A neutron
sources have to be used ensuring theprotection from ionizing
radiation to workers and population. Doors microswitches have tobe
installed to control the area access when the neutron beam is on.
Special keys systemto switch on the neutron generator is needed.
Neutron and gamma monitor for theambient dose measures have to be
installed in such a way to take under control
radiationlevels.ATTENDED RESULTS: - A unique neutron beam facility
will be realized using a noncommercial fusion generator. When the
neutron generator will be installed and all testswill be taken over
a stable and well characterized 2,5 MeV neutron flux will be
available tobe used for epithermal, thermal and cold neutron
production. Neutrons could be used fordifferent kinds of
application from materials analysis to medical physics. -Titanium
is the most efficient metal hydrides for neutron generation. In
steady-state, thedeuterium concentrations are believed to reach
certain saturation values, which dependon the target temperature.
In the theoretical calculation it is assumed that the
saturationconcentration are constant over the particle range, and
that the target thickness is largerthan the particle range. For a
deuteron beam of current I and energy E composed ofmonoatomic
species the total number of neutrons produced per second can be
computedusing the integral form of the thick-target yield equation.
When the machine and thecontrol and beam monitoring systems will be
installed, we will be able to compare thecalculated neutron yield
per current unit in Ti target as a function of the beam
energycurrent density and target temperature. Deliverables: 1)
design and acquisition of the necessary material and
instrumentation: month 8; 2) completion of neutron source
installation: month 14; 3) characterization of the bare neutron
source: month 24; 4) report on neutron source performances: month
24; 5) report on neutron thermal column charachteristics: month 30;
6) report on the whole system performances: month 36.
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AGENCY PARTICIPANT: Dipartimento di Fisica SperimentaleSTARTING
MONTH PEOPLE ACTIVITIES: 1ENDING MONTH PEOPLE ACTIVITIES:
36PEOPLE/MONTHS ACTIVITIES FOR PARTICIPANT: 24
AGENCY PARTICIPANT: Istituto Nazionale di Fisica
NucleareSTARTING MONTH PEOPLE ACTIVITIES: 1ENDING MONTH PEOPLE
ACTIVITIES: 36PEOPLE/MONTHS ACTIVITIES FOR PARTICIPANT: 33
AGENCY PARTICIPANT: SEPA S.p.A.STARTING MONTH PEOPLE ACTIVITIES:
1ENDING MONTH PEOPLE ACTIVITIES: 36PEOPLE/MONTHS ACTIVITIES FOR
PARTICIPANT: 3
NUMBER: 2TITLE: Design and manufacturing of thermal/cold
columnRESPONSIBLE: ALBA ZANINISTARTING MONTH: 1ENDING MONTH:
36OBJECTIVES: The neutron generator, characterized by a coaxial
design, is based on D–Dreaction producing 2.45MeV and it is
designed to provide a neutron yield >10^11 s-1.While the neutron
energy distribution, for deuterium beam energies < 160 keV,
spreadbetween 2.9 MeV and 2.1 MeV, the angular distribution is
isotropic. In order to performneutron tomography these particles
need to be moderate to lower energies and thisrequires the
construction of a Beam Shaping Assembly (BSA). While the primary
purposeof this assembly is to shift the neutron energy spectrum to
lower energies maintainingadequate beam flux, several different
components, such as moderator, reflector, gammashielding and
delimiter, are needed to make proper use of all neutrons and to
properlytailor many aspects of the beam. The optimisation of BSA
consists in the choice ofappropriate materials, thicknesses and
shapes in order to get the best neutron spectrumat the beam exit.
Concerning the angular distribution of the beam, the best option
seemsto be a quasi-parallel beam with a L/D-ratio (that is a
measure of the beam collimation,where D is the diameter of an
aperture and L the distance between aperture andmeasuring position)
as high as achievable. In this way, no geometrical distortion
occursand the spatial resolution should be limited only by the
properties of the detector device. At present thermal neutrons are
mainly used for tomography, but there are also some
10 of 114
Participant to the Work Package: Installation and
characterization of neutrongenerator
TOTAL PEOPLE/MONTHS OF ACTIVITY Installation and
characterization ofneutron generator: 60
Work Package: Design and manufacturing of thermal/cold
column
-
options with cold neutrons. The main reason to use cold neutrons
is to improve the imagecontrast. Far from resonances, the
cross-section for neutron capture is inverselyproportional to the
neutron velocity, or using the particle-wave duality, is
proportional to itswavelength. Thus comparing thermal (1.8
angström) and cold neutrons (5.5 angström), theimage contrast
obtained with cold neutrons is generally about the cube of that
withthermal neutrons. The objective of WP2 is to: 1) study by means
of simulation code a thermal column suitable to perform
neutrontomography on different objects; 2) design and manufacturing
thermal column; 3) perform test, compare simulation results with
measurements and characterize thethermal neutron field; 4)
investigate, design and manufacturing a new column to produce cold
neutron toimprove the image contrast; 5) perform test on the cold
column, compare simulation results with measurements
andcharacterize the neutron field.DESCRIPTION: The Monte Carlo code
MCNP-4C will be used to model the neutronsource, to study the BSA
and to simulate the neutron and photon transport in the column.The
most suitable materials to moderate and reflect neutrons will be
investigated througha careful analysis of materials macroscopic
cross-sections (elastic scattering, inelasticscattering,
absorption), obtained from the ENDF/ B-VI cross-sections libraries.
Moreoverattention will be paid to the material activation in order
to meet the radioprotectionrequirements. The activation analysis
will be carried out with FISPACT (NEA-1564) code.It is a complete
tool for the calculation of activation in materials exposed to
neutronswhere the neutron energy does not exceed 20 MeV. The part
of the code consist of theinventory code FISPACT-2003, the
EAF-2001, EAF-2003 and the FENDL-2 data libraries.EAF contains
cross section data of neutron-induced reactions for energies
between 1.0E-5 eV and 20 MeV. The primary job of the BSA is to
provide the moderation of the neutron beam to thermal orcold
energies by interaction with moderator materials. It is important
to choose materialsthat cause the rapid loss of energy to the
desired energy range without overmoderation orloss of neutrons,
moreover the material thickness should also be as little as
possible todecrease the geometric attenuation of the beam. A
reflector is needed to maximize thetotal neutron flux to the beam
exit window. It should be thick enough to provide
adequatereflection but it should also not significantly absorb
useful neutrons. The optimization ofthe reflector is very important
especially with a co-axial neutron source, where neutronsare not
preferentially directed towards the exit window. A gamma shielding
is required ifgamma-ray contamination from the BSA components is
determined to be significant. Itconsists of a thin plate at the
edge of moderator or it covers the exit window at the edge ofthe
delimiter. Moreover, depending on the shielding requirements of the
treatment room,neutron or gamma shielding (or both) also may be
added around the entire BSA. Thegamma component in the moderated
neutron beam, coming from the compact generator,is very poor
compared to that one in the reactor, where photons produced by
secondaryreactions in the moderator are added to the gamma created
in the reactor core. A beam delimiter must be provided to absorb
neutrons that are not aimed at the targetvolume, it should be
cone-shape to channel neutrons to the target and be thick enough
toprovide a good beam directionality. Different beam delimiter will
be designed in order tochange easily the dimension of the neutron
field (from 1x1 cm^2 to 20x20 cm^2)according to the experimental
set-up. The beams will be compared through the assessment of free
beam parameters such as:
11 of 114
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- thermal and/or cold neutron flux (> 1 E5 cm-2 s-1). - fast
neutron contamination and photon contamination as low as possible,
- beam collimation as high as possible. An important parameter for
the tomography is the L/D ratio; it is a measure of the
beamcollimation, where D is the diameter of an aperture and L the
distance between apertureand measuring position. The larger the L/D
ratio the better is the beam collimation. Theresolution is equal to
the geometrical blur b=d/(L/D) where d is the distance
betweenobject and detector screen. The L/D ratio can be increased
to values of about 500 and the spatial resolution improvesto up to
200 micrometers. When the simulation step will be completed the
columns realization will start. Test will berealized on each
component and measurements will be compared always with
thesimulation data. The final step consists in the complete
characterization of the neutron field and in theinvestigation of
the performance of the electronic devices and sensors used in
theexperimental set up, under operative conditions.ATTENDED
RESULTS: By the careful analysis of materials macroscopic
cross-sections itis expected to select as good moderator materials:
graphite, polyethylene, PMMA andheavy water. Concerning reflector
materials C, Pb and Bi should effectively reflectneutrons back to
the exit window, while a gamma shielding (made of Pb or Bi)
shouldabsorb efficiently residual gammas. By means of MCNP-4c code
a detailed simulation of the neutron source will be providedand
different configurations (BSA) of the thermal column will be
realized in order tooptimise the neutron beam at the collimator
aperture. The thermal column will be manufactured following the
optimized design and a completecharacterization of the beam will be
provided. The new column will have a modularstructure in order to
modify the beam according to the experimental set-up and it will
beequipped with different collimator to change beam dimensions. A
feasibility study of the cold column will be completed and
following the same procedureexplained above the column will be
manufactured following the optimized design andcharacterized.
Deliverables: 1) design of the thermal column and acquisition of
the necessary materials: month 15; 2) completion of thermal column:
month 21; 3) completion of thermal column installation: month 27;
4) report on feasibility of a cold neutron column: month 30; 5)
completion of thermal column optimization: month 30; 6) report on
the whole system performances: month 36.
AGENCY PARTICIPANT: Istituto Nazionale di Fisica
NucleareSTARTING MONTH PEOPLE ACTIVITIES: 1ENDING MONTH PEOPLE
ACTIVITIES: 36
12 of 114
Participant to the Work Package: Design and manufacturing of
thermal/coldcolumn
-
PEOPLE/MONTHS ACTIVITIES FOR PARTICIPANT: 30
AGENCY PARTICIPANT: Dipartimento di Fisica SperimentaleSTARTING
MONTH PEOPLE ACTIVITIES: 1ENDING MONTH PEOPLE ACTIVITIES:
36PEOPLE/MONTHS ACTIVITIES FOR PARTICIPANT: 39
NUMBER: 3TITLE: Neutron detection and tomographyRESPONSIBLE:
VINCENZO MONACOSTARTING MONTH: 1ENDING MONTH: 36OBJECTIVES: The
main objective of this work package is to obtain an apparatus
forComputed axial Tomography (CT) using thermal neutron on objects
of interest in the fieldof cultural heritage. Being the neutron
source developed in WP1 and WP2, this WP will befocused on neutron
detection and on the assemblage of the whole system. Thermal or
cold neutron tomography provide within a relative short time (from
few minutesto few hours) a three-dimensional inside view of thick
objects with spatial resolution downto 100 micrometers, in the case
of few centimetre objects. Similar in principle to X-ray CT,the
neutron tomography technique is based on the measurement of the
attenuation of aneutron beam passing through an object. For a
computed neutron tomography,two–dimensional (2D) transmission
images of the sample taken from different view anglesare required,
whereas the quality of the tomography depends strongly on the
number ofimages from different view angles. Therefore the
experimental setup for neutron tomography consists of the neutron
source(mainly thermal neutron, but cold neutrons are also used)
with a collimator (developed inWP1 e WP2), a rotary table for the
rotation of the object (developed in WP6), a properdetector and a
motion control system that synchronizes the rotary table and the
detector.The common arrangement is a fixed beam line and a
stationary detector, whereas thesample is rotated between them on a
turn table. In this way, the necessary projections inorder to
define a 3D map of the object are obtained (of the order of few
hundred). The detection principle is the following: the neutron
beam penetrating the sample isattenuated according to the sample
material and geometry and reaches the neutronsensitive scintillator
screen, where each detected neutron triggers a photon cascade.
Thelight emitted by the scintillator is reflected to the CCD-camera
by a mirror. This detectordesign allows to place the camera out of
the direct neutron beam to protect the chip fromradiation damage.
The detection system of the camera is read out by the computer.
After exposure the computer sends a trigger signal to the rotary
table, the sample is rotated of adefined angle and the next
exposure starts automatically. In the past years, severaltechniques
in digital imaging were successfully applied providing high
sensitivity detectorswith important performances regarding their
dynamic range and linearity. This holdsmainly for imaging plates
and detectors based on CCD cameras with a scintillator screen
13 of 114
TOTAL PEOPLE/MONTHS OF ACTIVITY Design and manufacturing
ofthermal/cold column: 69
Work Package: Neutron detection and tomography
-
as primary neutron-to-light converter. Other methods are not yet
completely optimised forneutron imaging (amorphous silicon arrays,
micro-strip gas counters), but have a highpotential as detectors in
radiography and in neutron scattering experiments as well. The
final goal of this WP will be met through the following phases: 1)
study, design and acquisition of the necessary material and
instrumentation (12months); 2) construction and characterization of
the detectors (6 months); 3) detector test using a commercial
neutron class B source (6 months); 4) integration of the mechanical
structures (WP 6) with the source and detector,alignment,
calibration and tests with the acquisition and control software
developed bySEPA (2 months); 5) detector test using a collimated
class A neutron source (6 months); 6) system optimization and
verification of 3D reconstruction software developed in WP 7by
means of a number of tomographies on reference objects with
different compositionsand dimensions (2 months); 7) system
validation with CT scans on cultural heritage artefacts from public
and privatemuseum collections (2 months).DESCRIPTION: The first
phase consists in the study and design of the tomographicsystem to
be assembled. Here, innovative solutions for the detector will be
evaluated. Theneutron-to-visible-light converter usually consists
of a 420 µm-thick ZnS layer doped with aCu, Al, Au and Ag blend
with specified minimum resolution of 80 µm and homogeneity of±5.0%.
Neutrons passing through the sample and arriving in the
scintillator create alphaparticles by reaction with 6Li and the
alpha particles produce blue light scintillation byreaction with
ZnS. The scintillation light is peaked at 540nm and is reflected
out of thebeam path at 45° or 90° by a silver-free mirror, to limit
the radiation damage to the CCD.The distribution of the
scintillations is imaged on the CCD array by means of a
standardobjective lens or various lenses, to improve the spatial
resolution of the image, especiallyfor small samples. In some
cases, for thermal neutrons, the screen is made ofGd2O2S:Tb(Eu).
Screens with different phosphor loading are manufactured and
usedwith respect to different thermal neutron spectra of the source
to optimise detectionefficiency and spatial resolution. A composite
screen made of a silicon organic resin andembedded Gd2O2S:Tb(Eu) is
used for fast neutron imaging. The CCD will be mounted ona vertical
translation stage in order to accommodate different fields of view.
A lead glassplaced between the objective and the mirror will
protect the CCD chip from gamma raysemitted by the mirror and the
converter. Finally, the camera will be covered on its sides bytiles
of 6LiF polymers and lead bricks to shield it against neutrons and
gamma rays. Towork in low neutron flux regime, a high efficiency
detection system will be designed inorder to perform at least one
tomography within one working day. The camera will
benitrogen-cooled to reduce dark current, which is extremely
important for long exposuretimes caused by the low neutron flux to
gain a better signal to noise ratio. The mainrequirements for the
mirror will be: a high reflectivity (95%) of the light emitted by
thescintillator, generation of as few gamma-rays as possible and no
lasting activation of thematerials composing the mirror. In the
second and third phases the detector will be constructed and
characterized using acommercial neutron class B source with a
neutron flux few order of magnitude lower thanthe flux from the
main source that will be developed in WP1 and WP2. Tests
performedwith materials of various compositions and thicknesses
will be important to optimize thedetector and to reduce the noise.
The fourth phase will consist in the integration of the detector
with the mechanicalstructure (WP 5 and WP 6) that has few
components that are common with X-Ray CT.The software for the
movement of the mechanical parts developed for X-Ray CT will
beintegrated with the acquisition system of the neutron image by
means of a CCD camera.
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In the fifth phase the thermal neutron flux obtained in WP2 from
the main source will beused to obtain the first neutron images. The
whole system will be checked in a fixedconfiguration. In this
phase, it is foreseen that optimal measurement parameters will
bedefined, such as the distance between the source, the detector,
and the measured object,the neutron current and exposure time
(which needs to be adjusted according to thephysical
characteristics and dimensions of the object under analysis). Also
in this phasetests will be performed with materials of various
compositions and thicknesses. The sixth phase will be devoted to
the first actual neutron tomography tests on referenceobjects.
These will be fundamental to evaluate the functionality of the
whole system. Atthe end of this phase, the whole structure will be
ready to perform measurements onobjects of interest in the field of
cultural heritage. In the final phase, system validation will be
carried out on works of art from public andprivate museum
collections.ATTENDED RESULTS: At present neutron tomography can be
realized by means ofthermal and/or cold neutrons mainly produced by
nuclear reactor. The main expectedresult of this WP is to obtain an
innovative instrument for CT neutron scans on large scaleobjects or
high-resolution scans on small objects using a compact D-D fusion
reactionneutron source. The apparatus will be coupled to the X-Ray
tomography systemdeveloped in WP 5. The number of analysis
techniques available to cultural heritage researchers is
constantlygrowing, but so is the demand for non-invasive methods to
unveil the secrets hiddeninside archaeological objects. The
information output from neutron CT should be uniqueand not
available by other routine archaeometric tools. The samples that
can be analyzedare hardly accessible by other diagnostic techniques
like, for example, solid compositeobjects with complex structure
but simple raw materials: casts containing a core, jewellerywith
inlays and multi-layered objects (coins, belts, iron swords in an
organic - wood andleather - sheath with metal fittings, fibulas).
The specific advantage of neutrons compared to X-rays is their high
interaction probabilitywith hydrogen and the lower attenuation in
several heavy elements which are “black” for X-rays (e.g. lead,
bismuth, uranium). This gives the justification for using neutrons
forspecial applications where X-rays must fail even if neutron
imaging is more expensive anddemanding. Moreover it will be
possible to use the neutron CT developed in various other fields:
spaceindustry, nuclear industry, geology, biology, dentistry, etc.
The investigation of moistureand corrosion, the detection of
explosives and adhesive connections and the inspection ofdefects in
nuclear fuel or in thick metallic samples are examples where
neutron can beutilised favourably. Deliverables. 1) design and
acquisition of the necessary material and instrumentation: month
12; 2) delivery of detector system: month 18; 3) report on detector
performaces using radiation sources: month 18; 4) report on
detector performaces using class B neutron source: month 24; 5)
delivery of neutron CT mechanical structure, including software
controls: month 26; 6) report on detector performaces using class A
neutron source: month 32; 7) report on the whole system
performances: month 34; 8) report on first neutron CT on cultural
heritage artifact: month 36.
15 of 114
Participant to the Work Package: Neutron detection and
tomography
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AGENCY PARTICIPANT: Istituto Nazionale di Fisica
NucleareSTARTING MONTH PEOPLE ACTIVITIES: 1ENDING MONTH PEOPLE
ACTIVITIES: 36PEOPLE/MONTHS ACTIVITIES FOR PARTICIPANT: 33
AGENCY PARTICIPANT: Dipartimento di Fisica SperimentaleSTARTING
MONTH PEOPLE ACTIVITIES: 1ENDING MONTH PEOPLE ACTIVITIES:
36PEOPLE/MONTHS ACTIVITIES FOR PARTICIPANT: 39
AGENCY PARTICIPANT: FONDAZIONE CENTRO PER LA CONSERVAZIONE E
ILRESTAURO DEI BENI CULTURALI "LA VENARIA REALE"STARTING MONTH
PEOPLE ACTIVITIES: 24ENDING MONTH PEOPLE ACTIVITIES:
36PEOPLE/MONTHS ACTIVITIES FOR PARTICIPANT: 7
AGENCY PARTICIPANT: SEPA S.p.A.STARTING MONTH PEOPLE ACTIVITIES:
1ENDING MONTH PEOPLE ACTIVITIES: 36PEOPLE/MONTHS ACTIVITIES FOR
PARTICIPANT: 27
NUMBER: 4TITLE: Prompt Gamma Activation AnalysisRESPONSIBLE:
EDOARDO DETOMASTARTING MONTH: 1ENDING MONTH: 36OBJECTIVES: The main
objective of this WP is the construction of an apparatus for
thedetection of gamma rays generated from the interaction of a
neutron beam with thesample. The aim is to detect the gamma rays
generated from neutron capture by atomicnuclei produced in
sub-nanosecond time intervals (PGAA: Prompt Gamma
ActivationAnalysis). The gamma rays are characteristic of the
nucleus that has emitted them, andtherefore the energy detection of
the latter allows the identification of the chemicalelements
composing the sample under investigation. The sensitivity depends
on thechemical element and is particularly high in the case of
light elements like hydrogen,boron or nitrogen. The determination
of the chemical composition is very important in many fields: in
culturalheritage, to be able to determine chemical composition
without the need to extractsamples is of fundamental importance, as
it allows specific work on an object withoutdamaging it. Some
examples of this are the identification of the constituent material
ofobjects present inside sealed amphorae, or the composition of
glues or fillers used toconsolidate wooden statues, or the
determination of the material used for the soldering of
16 of 114
TOTAL PEOPLE/MONTHS OF ACTIVITY Neutron detection and
tomography:106
Work Package: Prompt Gamma Activation Analysis
-
metal statues. Currently, this technique has been primarily
developed in research laboratories where anuclear reactor is
present, allowing to have thermal or cold neutrons with sufficient
fluxesto carry out this type of analysis (between 10^7 and 10^9
n/cm2 s). Usually the structuresfor this type of analysis are
optimized for small samples (below 1 g.) and allow thedetermination
of the sample composition with great accuracy, which is variable
with theinvolved elements, but can reach above 10 ppb (10^-8). To
obtain this kind of precision,often dedicated chambers are used in
proximity of the outlet of the neutron flux, to reducethe neutron
path in air to a minimum. In these chambers there is vacuum or He
is fixed toreduce neutron scattering and gamma ray capture by air.
Cultural heritage artefacts areusually quite large and do not allow
this type of analysis, unless some sort of sample isextracted,
which deteriorates the object under investigation. On the other
hand, often it isnot necessary to obtain such high resolutions,
because the material can be identified andone can obtain a good
initial estimate of the composition. The aim is therefore to
assemble two instruments that use the same detection system.The
first, to be coupled to the neutron tomography, would allow the
identification of theconstituent materials of the object under
investigation (which can be quite large) with alimited precision,
but sufficient for initial aims. The second would require the
developmentof a dedicated analysis chamber, allowing to carry out
measurements to determine thecomposition of small samples with
great sensitivity (useful in the field of cultural heritagefor
dating and determination of the origin of samples). The main goal
of this WP will be attained by subdividing its development in
variousphases: 1) design of the detection apparatus with choice of
the detectors (12 months); 2) construction of the apparatus, of the
detector shielding, of the detecting structure andpreparation of
the management software; detector calibration with calibration
sources (10months); 3) test using a class B neutron generator
(flux< 10^7 n/s) on materials of differentcomposition (8
months); 4) optimization of the apparatus using the class A neutron
generator (2 months); 5) test during trial neutron tomographies (2
months); 6) analysis of samples from public and private art
collections (2 months).DESCRIPTION: This work package will be
implemented by SEPA s.p.a., in collaborationwith the Dipartimento
di Fisica Sperimentale of the University of Torino (DFS) and
INFN.The work is subdivided in various phases, described below: 1)
The first phase is relative to the design of the apparatus. This
includes the part ofgamma ray detection which is usually obtained
with more than one detector. In the mostadvanced systems a
Germanium detector is used (HPGe) with a 65% efficiency
andapproximately 2 keV resolution at 1333 KeV. Associated to this
detector is a BGOscintillator for Compton scattering suppression.
For rapid measurements anotherscintillator-photomultiplier system
will be used. Also, the signal control electronics will bedesigned,
the support structure and the detector shielding, which is
necessary to reducebackground noise to a minimum and obtain high
precision measurements. It will also benecessary to evaluate which
acquisition software to use for spectrum analysis. In thisphase
there will also be the design of a vacuum chamber to carry out
high-sensitivitymeasurements on small samples. This will involve an
adequate choice of materials(usually aluminium, due to its reduced
interaction with neutrons), geometries and thewhole vacuum system.
2) The second phase, which will consist in the detector
calibration, will be carried out in
17 of 114
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parallel to the shielding and support structure assembly in the
INFN mechanical workshop((WP 6). The calibration will need to be
carried out both to evaluate the efficiency and theenergy scale;
for the first of the two, radioactive sources are necessary to
generatephotons with characteristic energies up to 1500 keV (137Cs,
241Am, 60Co, 134Cs,152Eu and 133Ba) whilst to extend the scale up
to approximately 11 MeV further peaksare necessary due to (n,g)
reactions, e.g. those for Cl from KCl and nitrogen frommelanin, for
which a neutron source is necessary, and will thus be carried out
in the nextphase. The necessary radioactive sources for this
calibration are already present at DFS,who will have a support role
in this phase, with qualified personnel to carry out this type
ofactivity. 3) The third phase will consist in tests of the
installed structure by means of a class Bneutron source, which is
less powerful than the source that will be installed in the
finalversion, but is nevertheless fundamental to carry out the
first measurements andcomplete the calibration up to high energies.
In this way, all necessary tests on differentmaterials and it will
be possible to evaluate the functionality of the spectrum
acquisitionsoftware and if need be improve its performance. 4) The
fourth phase, which will be carried out using the neutron source
with a greater flux(WP 1 and 2) and the final structure, will
consist of background measurements without asample, only with a
neutron source. These will be performed in both configurations,
i.e.both in a tomography simulation and in the installed analysis
chamber. In this phase acalibration of standards will also be
carried out to obtain a quantitative analysis asaccurate as
possible and evaluate the detection limits of the system. 5) The
fifth phase will consist in a detection test on large objects in a
tomographymeasurement. Thus, it will be possible to evaluate the
functionality of the whole apparatusand its integration with the
tomography system. 6) The final phase will consist in tests on
objects from public and private art collectionsand will allow to
obtain first results of interest for the field of cultural
heritage.ATTENDED RESULTS: The main result from this WP will be to
obtain a structure to carryout the PGAA on large samples that would
otherwise require sampling to be analysed.This will be of
fundamental importance for the “La Venaria Reale” Centre, as they
will allownot only neutron tomographies, but also composition
analyses of large objects.Furthermore this structure will be
capable of carrying out compositional analyses with highprecision,
which is of fundamental importance in the field of cultural
heritage for datingand origin analysis. To perform this WP,
detector characterization will also be carried out; it will also
bepossible to use it in other types of gamma measurements. One of
the advantages of thistype of structure will be that it will not
require the presence of a nuclear reactor, contraryto all other
facilities perform this type of measurement. SEPA will obtain a
number of advantages from this work, as it will develop
instrumentationthat can be applied in other fields: PGAA can be
used in all cases when particularelements need to be detected,
especially light elements, with great precision, e.g. in
theanalysis of new materials, or in the food industry to verify the
absence of elements thatare dangerous for health. Furthermore, PGAA
has numerous applications in chemistry,geology, archaeology,
agriculture, environment studies, biology, medicine and industry.
Deliverables.
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1) design and acquisition of the necessary material and
instrumentation: month 12; 2) delivery of detector system: month
22; 3) report on detector performaces using radiation sources:
month 22; 4) report on detector performaces using class B neutron
source: month 30; 5) report on detector performaces using class A
neutron source: month 32; 6) report on PGAA analysis using neutron
CT apparatus: month 34; 7) report on first PGAA analysis on
cultural heritage artifact: month 36.
AGENCY PARTICIPANT: Dipartimento di Fisica SperimentaleSTARTING
MONTH PEOPLE ACTIVITIES: 1ENDING MONTH PEOPLE ACTIVITIES:
36PEOPLE/MONTHS ACTIVITIES FOR PARTICIPANT: 21
AGENCY PARTICIPANT: FONDAZIONE CENTRO PER LA CONSERVAZIONE E
ILRESTAURO DEI BENI CULTURALI "LA VENARIA REALE"STARTING MONTH
PEOPLE ACTIVITIES: 24ENDING MONTH PEOPLE ACTIVITIES:
36PEOPLE/MONTHS ACTIVITIES FOR PARTICIPANT: 2
AGENCY PARTICIPANT: SEPA S.p.A.STARTING MONTH PEOPLE ACTIVITIES:
1ENDING MONTH PEOPLE ACTIVITIES: 36PEOPLE/MONTHS ACTIVITIES FOR
PARTICIPANT: 72
NUMBER: 5TITLE: X-Ray TomographyRESPONSIBLE: ALESSANDRO
RESTARTING MONTH: 1ENDING MONTH: 36OBJECTIVES: The main objective
of this work package is to obtain an apparatus forComputed axial
Tomography (CT) using X-rays on objects of interest in the field
ofcultural heritage. The intent is to obtain tomographies both on
artefacts of considerablesize with a resolution of the order of
medical CT scans (half a millimeter), and on smallerobjects with a
higher resolution (below 0,5mm). Due to the numerous applications
in the medical field, X-ray tomography is a well-established
technique and operates with X-rays having and energy comprised
between 30and 150 KeV. In the field of cultural heritage, however,
new issues emerge. In somecases there is the need to internally
characterize small objects with a higher resolution
19 of 114
Participant to the Work Package: Prompt Gamma Activation
Analysis
TOTAL PEOPLE/MONTHS OF ACTIVITY Prompt Gamma ActivationAnalysis:
95
Work Package: X-Ray Tomography
-
than in a medical CT (about 0.5 mm) or to analyze large objects
(whose size exceeds thestandard 70 cm diameter) of irregular shape,
which in some cases cannot be transferredfrom museums or from
restoration centres. In the first case, to obtain high resolutions,
an accurate design of the X-raygenerator/object/detector system is
necessary, together with the use of non standardsources and
detectors. In the second case, it is necessary to develop
highly-flexible transportable systems toadapt to the different
types of artefacts under investigation. This includes the use
ofsources of various energies, to be defined based on preliminary
studies on the constituentmaterials of the objects under study, the
use of large detectors, and the development ofhigh-precision
translational mechanical systems. One of the possible ways to
attain CT scans on large objects with a high resolution is toadopt
a detector having smaller dimensions than the object and to perform
partial scansby translating the detector with a mechanical stage,
so as to scan the entire field of visioncontaining the object. The
partial scans need then to be merged together to obtain thecomplete
scan. It is therefore very important to develop dedicated software
applicationsboth to assemble the partial scans, starting from
single radiographs performed on differentportions of the artefacts
and from different views, both to reconstruct the
completetomography and to enable the subsequent visualization of
results. Complex imagemanagement tools are therefore necessary to
highlight the aspects of interest for theexperts in the field of
restoration. Concerning the large-scale objects, one of the
objectives is to assemble a system insidethe DFS bunker that is
essentially fixed, to be exploited in a complementary manner to
theneutron tomography system (WP 1,6) in order to obtain
complementary images to thelatter technique. Taking advantage of
the INFN mechanical workshop, the apparatus willbe constructed in a
suitably compact form as to be separated from the neutron CT
systemand transported to the Venaria Centre for Conservation and
Restoration or to museums inall cases when the artefact cannot be
displaced to the DFS. The entire system willmaintain its
characteristics of high flexibility necessary to study unique
objects, but at thesame time will be designed so as to be operated
by non-experts in nuclear physics. The final goal of this WP will
be met through the following phases: 1) study, design and
acquisition of the necessary material and instrumentation
(10months); 2) characterization of the X ray source; construction
and characterization of the detectors;construction of the
mechanical structures (WP 6) (8 months); 3) integration of the
mechanical structures (WP 6) with the source and
detector,alignment, calibration and tests with the acquisition and
management software developedby SEPA (6 months); 4) system
optimization and verification of 3D reconstruction software
developed in WP 7by means of a number of tomographies on reference
objects with different compositionsand dimensions (8 months); 5)
system validation with CT scans on cultural heritage artefacts from
public and privatemuseum collections (4 months).DESCRIPTION: This
WP will be managed by DFS in close collaboration with INFN andwith
the research group at the University of Bologna that has been
working on thesetopics for a number of years. The first phase
consists in the study and design of the tomographic system to
beassembled. Here, innovative solutions for the detector and the
generation and use of X-rays will be evaluated. According to the
project, the mechanical parts, housing, andstructures for system
mobility will be defined together with the INFN mechanicalworkshop,
together with all elements necessary for their functioning. Among
thesestructures are the shielding and security devices necessary
for radiation protection, to be
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defined and designed according to indications from qualified
experts based on legalrequirements. At the end of this phase the
detailed final project will be defined and X-raysources will be
made available, as well as the commercial components for the
detector(CCD, amorphous silicon panels, scintillation screens,
focusing system, fibre opticsystems for imaging…). In the second
phase, the sources and detectors will be characterized without
thetranslations system. The possibility of using a beam collimator
and shielding for the detector will be evaluated,to reduce
background noise due to the interaction of X-rays with the
electronic devices,producing noise and possible damage. In this
phase, it is foreseen that optimalmeasurement parameters will be
defined, such as the distance between the source, thedetector, and
the object to be measured, the beam energy, the current and
exposure time(which need to be adjusted according to the physical
characteristics and dimensions ofthe object under analysis). Many
tests will be required with materials of various compositions and
thicknesses toprovide a first estimation of the measurement times
necessary for various desireddimensions and resolutions. In this
phase, novel detectors will be tested, exploiting the know-how
emerging from high-energy experiments being carried out in this
field by INFN Torino. Other detectors will alsobe considered for
X-rays of higher energy than those commonly used for CT scans,
inview of the possible acquisition of a linear particle accelerator
for CT scans using above-MeV energies. The third phase will consist
in the installation of the mechanical structure (WP 6) and
itsintegration with the source and detector. The software for the
movement of themechanical parts will be developed through the INFN
– SEPA collaboration, and firstalignment and calibration tests for
the whole instrument will be carried out. In this phase,the image
acquisition software will be tested and future improvements will be
evaluated.The possibility of completely integrating the image
acquisition part with that of detectorpositioning in the case of
large objects for which partial scanning is necessary will lead toa
totally automated CT system, with a resulting reduction in
acquisition time, use ofhuman resources, and operator error
probability, as well as the opportunity to proceedwith the 3D image
reconstruction in parallel with image acquisition. The fourth phase
will be devoted to the first actual tomography tests on reference
objects.These will be fundamental to evaluate the functionality of
the whole system and will alsobe useful to test the image
reconstruction software developed in WP 7. At the end of thisphase,
the whole structure will be ready to perform measurements on real
large scaleobjects of interest in the field of cultural heritage.
In the final phase, system validation will be carried out on works
of art from public andprivate museum collections.ATTENDED RESULTS:
The main expected result is to obtain a flexible and
innovativeinstrument for CT X-ray scans on large scale objects or
high-resolution scans on smallobjects. The main apparatus will be
coupled to the neutron tomography system developedin WP 6, but will
also be constructed in such a manner as to be transportable. To
reach this goal, source and detector characterization will be
carried out, some of whichof new conception. The mechanical
translation stages will be also adaptable to otherinstruments and
will allow the use of additional sources and detectors to
thosecontemplated in this proposal. At the conclusion of the
project, the first tomographies will be obtained with
thisapparatus, and thus there will be the availability for the
Centro di Conservazione e
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Restauro “La Venaria Reale” of a structure for non-invasive
analysis of statues and objectsof large dimensions. The compact
structure of the apparatus will allow its displacement directly to
the site ofanalysis, in the case of a particularly large or
delicate object, which would not betransferable to DFS. All of this
would entail consistent advantages for the Centro diConservazione e
Restauro “La Venaria Reale”, which would acquire a powerful
instrumentof considerable importance for the study and restoration
of large scale artefacts. Forexample, in the case of wooden
statues, it would be possible to obtain information on theirentire
volume and detect in a non invasive manner the presence of defects
(insect holes,decayed zones, etc.), growth rings for the study of
ageing with dendrochronology, thestructure of the grain patterns,
presence of fillers or nails, wood density, constructionstructure,
etc.. It is to be observed that often the difficulties encountered
in achieving a CT instrument inthe field of cultural heritage are
quite similar to those present in other industrial fields(different
sized and shaped objects with various densities, presence of
inhomogeneities,metals and heavy materials, presence of various
constitutive materials, significantthicknesses, scarce relevance of
released dose). It is therefore clear that both sectors canbenefit
from this type of service and from the applicative results obtained
in this project.The growing interest in various industrial sectors
for the technique CT brings thistechnology to attention in the
field of non-destructive tests. This apparatus could therefore also
be employed for other purposes, mainly industrial,e.g. the analysis
of mechanical components with a resolution of about 100 µm or, in
thecase of a linear accelerator, of large scale objects that are
impossible to analyse withconventional CT instrumentation. This
could be extremely important, to extend thediagnostic possibilities
to a new class of materials (thicker and heavier), and thus
toextremely interesting items in the field of cultural heritage
(large bronze, stone and marbleartefacts) and simultaneously to
open up the possibility of using CT scans in the analysisof heavy
industrial components like aluminium or steel casts, or similar
items. Deliverables: 1) design and acquisition of the necessary
material and instrumentation: month 10; 2) delivery of all
mechanical parts and detectors: month 18; 3) characterization of
the X ray source: month 18; 4) report on final assembly of
mechanical structure and detector performances: month 18; 5)
delivery of the complete system and control software: month 24; 6)
report on the whole system performances: month 32; 7) report on 3D
reconstruction software performances: month 32; 8) report on first
X-ray CT on cultural heritage artefacts: month 36.
AGENCY PARTICIPANT: Dipartimento di Fisica SperimentaleSTARTING
MONTH PEOPLE ACTIVITIES: 1ENDING MONTH PEOPLE ACTIVITIES:
36PEOPLE/MONTHS ACTIVITIES FOR PARTICIPANT: 66
AGENCY PARTICIPANT: FONDAZIONE CENTRO PER LA CONSERVAZIONE E
ILRESTAURO DEI BENI CULTURALI "LA VENARIA REALE"STARTING MONTH
PEOPLE ACTIVITIES: 1ENDING MONTH PEOPLE ACTIVITIES: 36
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Participant to the Work Package: X-Ray Tomography
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PEOPLE/MONTHS ACTIVITIES FOR PARTICIPANT: 32
AGENCY PARTICIPANT: Istituto Nazionale di Fisica
NucleareSTARTING MONTH PEOPLE ACTIVITIES: 1ENDING MONTH PEOPLE
ACTIVITIES: 36PEOPLE/MONTHS ACTIVITIES FOR PARTICIPANT: 33
AGENCY PARTICIPANT: SEPA S.p.A.STARTING MONTH PEOPLE ACTIVITIES:
1ENDING MONTH PEOPLE ACTIVITIES: 36PEOPLE/MONTHS ACTIVITIES FOR
PARTICIPANT: 9
NUMBER: 6TITLE: Mechanical system for X-ray and neutron Computed
TomographyRESPONSIBLE: PAOLO MEREUSTARTING MONTH: 1ENDING MONTH:
36OBJECTIVES: Main goal of the present WP is to provide to the
neutron and X-ray source-detector systems a reliable, stable, and
accurate numerically controlled mechanicalstructure to perform fast
CT on artistic objects. Choice of the motor and control systemwill
be crucial for achieving the desired performances. The flexibility
of the structure in the relative positioning of the source, sample
to beanalyzed and X-ray or neutron detector, will allow for each
case a full optimization of theCT in terms of imaging resolution.
The modularity of the structure will allow quick disassembly and
reassembly to open thefeasibility of CT on artistic objects which
could not be moved away from their location. Thedesign of the
mechanics will be therefore organized to ease in the best possible
wayreassembly and installation, and all the necessary manuals to
make this operation will beprovided by the constructors. Special
care will be taken in the radiation test of all mechanical linear
encoders, whichshould operate and guarantee good performance in
large neutron and X-ray radiationenvironment. This is an important
aspect of the development of the mechanical structureand a relevant
goal to be accomplished to operate satisfactorily the CT devices.
Another important goal of this WP is the benchmarking of the
software for the motorcontrol and interfaces for data acquisition,
which will guarantee the correct machinebehaviour under operator
control. Two software levels are foreseen and will be developedin
the present WP. A low level software, developed at the motor
control CPU level, willprovide have all the necessary executables
and motor parameter definitions to bedownloaded in the motor
control firmware system. A higher level software is the GUI(Graphic
User Interface) which will allow user friendly interface of the
operator with themotor control programs. This part of the software
will be made in close collaboration ofINFN and University of Torino
experts and co-proponent (SEPA) software developers.
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TOTAL PEOPLE/MONTHS OF ACTIVITY X-Ray Tomography: 140
Work Package: Mechanical system for X-ray and neutron
ComputedTomography
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DESCRIPTION: The design and construction of the mechanical part
of the X-ray andneutron Computed Tomography system is under
responsibility of the engineering staff ofthe Istituto Nazionale di
Fisica Nucleare. The group of engineers and technicians involvedin
this task has very good skills and experience in the planning and
design of computercontrolled machine which have been developed and
used in the INFN laboratories in thepast years for the construction
of large area particle detectors. The accuracy required inHigh
Energy Physics experiments, even at scales of the order of few
meters, is betterthan 100 microns. On top of this, the accuracy in
the planning and construction ofequipments used for particle
detector assembly is crucial for the serial quality control of many
detectors. For this reasons the INFN staff is well suited to
design, develop, contruct,assemble and commission the CT mechanical
structure with motion controls andmonitoring system. Moreover it
should be stressed that the group has already beeninvolved in the
construction of a part of a CT system used to apply CT analysis
techniquesto a wooden statue of the 12th century actually located
in the CCR “la Venaria Reale”. TheCT will be done in february in
collaboration with INFN and University of Torino and INFNand
Univeristy of Bologna. The CT mechanical system will be designed
having in mind the following requirements: 1) precision and
stability of x-y gantry. Fast motor control together with high
mechanicalstability will be crucial in the image scanning and
therefore in the CT system duty cyclepotential. The duty cycle is
relevant to be considered from the very beginning as a keyparameter
of the mechanical assembly. The structure infact should grant short
CT timesin order to minimize the stationary period of art samples
in our laboratories and to boostthe frequency of CT which can be
performed. Positioning accuracy will be obtained withoptical linear
encoders, which will allow single axis precision of the order of
0.01mm; 2) precision rotation platform with good encoder
resolution. The object which will undergoCT will be placed on this
device. The distance between the the x-y gantry holding the X-ray
or neutron sensor and the platform will be tuned to maximize image
resolution (aimingto perform better than 0.1mm); 3) y movement for
vertical displacing of the X-ray source (necessary for CT to
voluminousobjects). The design of all mechanical parts and
interfaces will be done by INFN engineers.Construction of most
parts will be done by INFN technicians in the INFN
mechanicalworkshop in Torino. The full apparatus will be mounted
and fully commissioned in theINFN workshop. The commissioning will
include a campaign of measurements with alaser interferometer to
certify and calibrate all axes movements and the full
benchmarkingof all software controls. Later it will be transported
in the bunker of the Istituto di Fisica ofTorino, where it will be
reassembled and integrated with all the necessary parts(dosimeters,
sources, radioprotections system, detectors). The structure will be
disegned keeping in mind from the very beginning that it will be
ableto operate both on X-ray and neutron beams. Moreover it will be
modeled in order to beeasily transported (when needed) in other
locations (for the X-ray analysis only). This willopen the
possibility to carry on X-ray CT directly on the art samples in the
location andplace where they are conserved, and therefore to export
the application of this techniqueto a multiplicity of potentially
interested museums and galleries.ATTENDED RESULTS: Mechanical
complexity of CT systems is one of limiting factors ofthe diffusion
of this imaging method in the cultural heritage field. We expect
that the knowhow developed with INFN groups and invested in this
WP, will enhance the diffusion andthe use of this non invasive
analysis technique, both in cultural heritage and archeologyfields.
The tight collaboration with researchers of CCR “La Venaria Reale”
and with its
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School of Restoration will certainly have considerable profits
from the use of thisadvanced analysis tool, both in terms of
analysis of artistic samples prior restoration, andfor the
formation of young restorers of the school who will take enormous
advantage intheir professional preparation. The school will offer
their student the possibility to work inclose collaboration with
our groups and to use our facilities. The diffusion of the
results,well amplified by the large visibility of CCR in our
territory, will hopefully also stimulateinterest in X-ray and
neutron CT analysis in other fields, in particular in industry,
where itis known that both gamma and neutron imaging is often an
invaluable tool for mechanical(expecially metallic) samples to be
analyzed. This is particularly true for neutrons, whichhave known
applications in the investigation of moisture and corrosion, the
detection ofexplosives and adhesive connections and the inspection
of defects in nuclear fuel or inthick metallic samples. The use of
neutron CT tomography in industry is essentially limitedby the
difficulty to have facilities like the one described in the current
project, whichrequires not only expensive equipments but also a
certified bunker with controlled accesspremises, and dedicated,
experienced personnel trained not only to operate the structurebut
also for the interpretation of the results. We also expect that the
possibility to export X-ray CT in galleries and museums whichcannot
transport artistic objects of their collections might generate
spin-off in this field, afield which is certainly of great
relevance in Italy for its very important tradition and theamount
and importance of the national cultural heritage. Again it should
be emphasizedthat the design of the mechanical system should be
done, already at its earlier stage,having this possibility in mind.
Deliverables: 1) full design of the mechanical structure: month 8
2) mechanical structure components and machined parts delivery:
month 12 3) final mechanical structure assembly: month 18 4) report
on mechanical structure commissioning: month 24 5) report on final
commissioning with integrated devices (source and detectors): month
36
AGENCY PARTICIPANT: Istituto Nazionale di Fisica
NucleareSTARTING MONTH PEOPLE ACTIVITIES: 1ENDING MONTH PEOPLE
ACTIVITIES: 30PEOPLE/MONTHS ACTIVITIES FOR PARTICIPANT: 27
NUMBER: 7TITLE: X-Ray and neutron tomography and
imagingRESPONSIBLE: FILIPPO DE CECCOSTARTING MONTH: 1
25 of 114
Participant to the Work Package: Mechanical system for X-ray and
neutronComputed Tomography
TOTAL PEOPLE/MONTHS OF ACTIVITY Mechanical system for X-ray
andneutron Computed Tomography: 27
Work Package: X-Ray and neutron tomography and imaging
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ENDING MONTH: 36OBJECTIVES: Accomplishment of the goals foreseen
will be distributed in the three yearsprojects with the following
breakdown: Year 1. . All the effort of the imaging team will be
focused on developing a first working version ofthe reconstruction
algorithms. Year 2. . Refinement of reconstruction algorithms. .
Development of processing and visualization algorithms. Year 3. .
Further development of processing and visualization tools. .
Development of a GUI based software application integrating the
algorithms. . Installation of the processing workstation hardware
platform.DESCRIPTION: This WP deals with all activities related to
software developments on CTimage processing algorithms, controls,
handling and archiving. 1. Develop an image reconstruction
algorithms customized to our X-rays and neutrontomography scanner.
The aim of transmission tomography reconstruction algorithms is to
reconstruct the spatialdistribution of X-rays or neutrons
attenuation coefficients, i.e. the image, starting from theset of
radiographic projections of the sample, acquired at different
angles. As apreprocessing step, the acquired projections are
transformed in sinograms, by coordinatetransformation and
rebinning; here is when the cone-beam geometry of our scannersplays
a role. Sinograms correspond to the Radon transform of the image,
therefore,tomographic image reconstruction consists in fact, in
inverting the Radon transform. Thefiltered back-projection (FBP) is
a discretized and stabilized version of the inverse Radontransform,
and it is one of the most widely employed analytic reconstruction
algorithm. Itscomputational efficiency makes FBP suitable to treat
large reconstruction volumes andhigh resolutions, such as those of
our scanners. 2. To develop image reconstruction algorithms for the
paintings X-rays and K-thresholdradiography scanner. In the
paintings X-rays and K-threshold radiography, the detector acquires
small 2Dimages while scanning the surface of the painting. All the
partial images will be integratedin a single 2D image of the whole
scanned area, and subtracted images will be calculatedfor
K-threshold radiography. 3. Develop a set of image processing,
registration, and analysis tools, for the detailed andquantitative
examination of tomographic and radiographic images. Develop a 2D
and 3D scientific visualization framework, allowing optimal
inspection andanalysis of different types of cultural heritage
artworks, with our imaging modalities. In order to allow a detailed
examination of tomographic images, several processing
andvisualization algorit