The 2nd International Workshop on Fast Neutron Detectors and Applications (FNDA 2011)

593 Pages·81.121 MB·English

Topics
Fast neutron detectors, Methods and facilities for the production of fast neutrons,
Simulation of detectors and fast neutron facilities,
Signal processing and data analysis techniques, Applications
Jointly organized by: SOREQ NRC, Israel; Physikalisch-Technische Bundesanstalt, Germany;
Weizmann Institute of Science, Israel; University of Cape Town, South Africa
www.FNDA2011.de
The 2nd International Workshop on Fast Neutron Detectors and Applications (FNDA
2011) Proceedings Articles have been published in Journal of Instrumentation
(JINST), 2012, number 7

Detection of explosives and other illicit materials by a single nanosecond neutron pulses — Monte Carlo
simulation of the detection process
R Miklaszewski, U Wiacek, D Dworak, K Drozdowicz and V Gribkov
2012 JINST 7 C07006

A single-shot nanosecond neutron pulsed technique for the detection of fissile materials
V Gribkov, R A Miklaszewski, M Chernyshova, M Scholz, R Prokopovicz, K Tomaszewski, K Drozdowicz,
U Wiacek, B Gabanska, D Dworak, K Pytel and A Zawadka
2012 JINST 7 C07005

Performance improvement of neutron flux monitor at KSTAR
Y -K Kim, S -K Lee, B -H Kang, J -B Son and G -D Kim
2012 JINST 7 C06013

A novel liquid-Xenon detector concept for combined fast-neutrons and gamma imaging and spectroscopy
A Breskin, I Israelashvili, M Cortesi, L Arazi, S Shchemelinin, R Chechik, V Dangendorf, B Bromberger and
D Vartsky
2012 JINST 7 C06008

Research and development of a dedicated collimator for 14.2 MeV fast neutrons for imaging using a D-T
generator
I Sabo-Napadensky, R Weiss-Babai, A Gayer, D Vartsky, D Bar, I Mor, R Chacham-Zada, M Cohen and N
Tamim
2012 JINST 7 C06005

Fast beam chopper at SARAF accelerator via RF deflector before RFQ
A Shor, D Vartsky, V Dangendorf, D Bar, Y Ben Aliz, D Berkovits, M Brandis, M B Goldberg, A Grin, I
Mardor, I Mor and L Weissman
2012 JINST 7 C06003

Diamond detectors for fast neutron measurements at pulsed spallation sources
M Rebai, L Giacomelli, C Andreani, A Fazzi, C D Frost, E Perelli Cippo, A Pietropaolo, N Rhodes, M
Tardocchi, E Schooneveld and G Gorini
2012 JINST 7 C05015

MONSTER: a time of flight spectrometer for ?-delayed neutron emission measurements
A R Garcia, T Martinez, D Cano-Ott, J Castilla, C Guerrero, J Marin, G Martinez, E Mendoza, M C Ovejero,
E M Reillo, C Santos, F J Tera, D Villamarin, R Nolte, J Agramunt, A Algora, J L Tain, K Banerjee, C
Bhattacharya, H Pentilla, S Rinta-Antila and D Gorelov
2012 JINST 7 C05012

Diagnostic neutron activation system for KSTAR
M S Cheon, Y S Lee, A C England, H S Kim, S Pak, C R Seon and H G Lee
2012 JINST 7 C05009

Fast-neutron detectors for nuclear physics experiments
R C Haight
2012 JINST 7 C05002

Fast-neutron imaging spectrometer based on liquid scintillator loaded capillaries
I Mor, D Vartsky, M Brandis, M B Goldberg, D Bar, I Mardor, V Dangendorf and B Bromberger
2012 JINST 7 C04021

Image recovery by removing stochastic artefacts identified as local asymmetries
K Osterloh, T Bucherl, U Zscherpel and U Ewert
2012 JINST 7 C04018

A new recoil proton telescope for characterisation of energy and fluence of fast neutron fields
J Taforeau, S Higueret, D Husson, L Lebreton, T D Le and M Petit
2012 JINST 7 C04015

Nuclear astrophysics with neutrons
I Dillmann and R Reifarth
2012 JINST 7 C04014

Fusion neutron diagnostics on ITER tokamak
L Bertalot, R Barnsley, M F Direz, J M Drevon, A Encheva, S Jakhar, Y Kashchuk, K M Patel, A P
Arumugam, V Udintsev, C Walker and M Walsh
2012 JINST 7 C04012

Characterization of the IRSN neutron multisphere spectrometer (HERMEIS) at European standard calibration
fields
A Cheminet, V Lacoste, V Gressier, G Hubert, A Martin and M Pepino
2012 JINST 7 C04007

Liquid scintillators and composites in fast neutron detection
J Iwanowska, L Swiderski and M Moszynski
2012 JINST 7 C04004

Neutron measurements with Time-Resolved Event-Counting Optical Radiation (TRECOR) detector
M Brandis, D Vartsky, V Dangendorf, B Bromberger, D Bar, M B Goldberg, K Tittelmeier, E Friedman, A
Czasch, I Mardor, I Mor and M Weierganz
2012 JINST 7 C04003

Pyroelectric crystal D-D and D-T neutron generators
Y Danon2012 JINST 7 C04002

Light yield and n-? pulse-shape discrimination of liquid scintillators based on linear alkyl benzene
T Kogler, A R Junghans, R Beyer, R Hannaske, R Massarczyk, R Schwengner and A Wagner
2012 JINST 7 C03047
C03047

Neutron medical treatment of tumours — a survey of facilities
F M Wagner, B Loeper-Kabasakal and H Breitkreutz
2012 JINST 7 C03041

SNM detection by means of thermal neutron interrogation and a liquid scintillation detector
A Ocherashvili, E Roesgen, A Beck, E N Caspi, M Mosconi, J -M Crochemore and B Pedersen
2012 JINST 7 C03037

Fast neutron detection with pressurized 4-He scintillation detectors
R Chandra, G Davatz, H Friederich, U Gendotti and D Murer
2012 JINST 7 C03035

Feasibility of a large area detector for fast neutron imaging
E Bogolubov, A Koshelev, V Mikerov and A Sviridov
2012 JINST 7 C03034

Neutron measurements in ITER using the Radial Neutron Camera
D Marocco, B Esposito and F Moro
2012 JINST 7 C03033

Novel neutron sources at the Radiological Research Accelerator Facility
Y Xu, G Garty, S A Marino, T N Massey, G Randers-Pehrson, G W Johnson and D J Brenner
2012 JINST 7 C03031
Two detector arrays for fast neutrons at LANSCE
R C Haight, H Y Lee, T N Taddeucci, J M O'Donnell, B A Perdue, N Fotiades, M Devlin, J L Ullmann, A
Laptev, T Bredeweg, M Jandel, R O Nelson, S A Wender, M C White, C Y Wu, E Kwan, A Chyzh, R
Henderson and J Gostic
2012 JINST 7 C03028

Electrometric sensors for neutron radiation: conceptual study
E Bogolubov, A Koshelev, V Mikerov and A Sviridov
2012 JINST 7 C03026

Neutron diagnostics at the Wendelstein 7-X stellarator
W Schneider, B Wiegel, F Grunauer, R Burhenn, S Koch, H Schuhmacher and A Zimbal
2012 JINST 7 C03025

Monte-Carlo simulations of neutron-induced activation in a Fast-Neutron and Gamma-Based Cargo
Inspection System
B Bromberger, D Bar, M Brandis, V Dangendorf, M B Goldberg, F Kaufmann, I Mor, R Nolte, M
Schmiedel, K Tittelmeier, D Vartsky and H Wershofen
2012 JINST 7 C03024

Results for the response function determination of the Compact Neutron Spectrometer
F Gagnon-Moisan, M Reginatto and A Zimba
l2012 JINST 7 C03023

Determination of the photon spectrum in an intense fission neutron beam
M Jungwirth, H Breitkreutz, F M Wagner and T Bucher
l2012 JINST 7 C03022

Towards high efficiency solid-state thermal and fast neutron detectors
Y Danon, J Clinton, K C Huang, N LiCausi, R Dahal, J J Q Lu and I Bhat
2012 JINST 7 C03014

nGEM neutron diagnostic concept for high power deuterium beams
G Croci, M Rebai, G Claps, M Cavenago, M Dalla Palma, G Gervasini, G Grosso, F Murtas, R Pasqualotto,
E Perelli Cippo, M Tardocchi, M Tollin and G Gorini
2012 JINST 7 C03010

Neutron resonance spectroscopy for the characterization of materials and objects
P Schillebeeckx, A Borella, F Emiliani, G Gorini, W Kockelmann, S Kopecky, C Lampoudis, M Moxon, E
Perelli Cippo, H Postma, N J Rhodes, E M Schooneveld and C Van Beveren
2012 JINST 7 C03009

Liquefied Noble Gas (LNG) detectors for detection of nuclear materials
J A Nikkel, T Gozani, C Brown, J Kwong, D N McKinsey, Y Shin, S Kane, C Gary and M Firestone
2012 JINST 7 C03007

First neutron spectrometry measurements in the ASDEX Upgrade tokamak
G Tardini, A Zimbal, B Esposito, F Gagnon-Moisan, D Marocco, R Neu, H Schuhmacher and the ASDEX
Upgrade Team
2012 JINST 7 C03004

Concept of a novel fast neutron imaging detector based on THGEM for fan-beam tomography applications
M Cortesi, R Zboray, R Adams, V Dangendorf and H -M Prasser
2012 JINST 7 C02056

Time and position sensitive single photon detector for scintillator read-out
S Schossler, B Bromberger, M Brandis, L Ph H Schmidt, K Tittelmeier, A Czasch, V Dangendorf and O
Jagutzki
2012 JINST 7 C02048

Characterization methods for an accelerator based fast-neutron facility
C Franklyn and G C Daniels
2012 JINST 7 C02043

The investigation of fast neutron Threshold Activation Detectors (TAD)
T Gozani, M J King and J Stevenson
2012 JINST 7 C02042

Fast neutron inelastic scattering at the nELBE facility
R Beyer, D Bemmerer, E Grosse, R Hannaske, A R Junghans, M Kempe, T Kogler, R Massarczyk, R Nolte,
R Schwengner and A Wagner
2012 JINST 7 C02020
PUBLISHEDBYIOPPUBLISHINGFORSISSAMEDIALAB
RECEIVED:January9,2012
REVISED:April12,2012
ACCEPTED:May21,2012
PUBLISHED:July16,2012
2nd INTERNATIONAL WORKSHOP ON FAST NEUTRON DETECTORS AND APPLICATIONS,
NOVEMBER 6–11 2011,
EIN GEDI, ISRAEL
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Detection of explosives and other illicit materials by
J
a single nanosecond neutron pulses — Monte Carlo
I
simulation of the detection process
N
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R. Miklaszewski,a,1 U. Wia˛cek,b D. Dworak,b K. Drozdowiczb and V. Gribkovc 7
aInstituteofPlasmaPhysicsandLaserMicrofusion,
23Herystr.,01-497Warszaw,Poland C
bInstituteofNuclearPhysics,PolishAcademyofSciences,
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147Radzikowskiegostr.,31-342Krako´w,Poland
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cBaikovInstituteofMetallurgyandMaterialsScience,
49Leninskiipr.,119991Moscow,Russia 0
E-mail: [email protected] 0
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1Correspondingauthor.
(cid:13)c 2012IOPPublishingLtdandSissaMedialabsrl doi:10.1088/1748-0221/7/07/C07006
ABSTRACT: Recent progress in the development of a Nanosecond Impulse Neutron Investigation
System(NINIS)intendedforinterrogationofhiddenobjects(explosivesandotherillicitmaterials)
bymeansofmeasuringelasticallyandnon-elasticallyscatteredneutronsispresented. Themethod
uses very bright neutron pulses having durations of the order of few nanoseconds, generated by a
dense plasma focus (DPF) devices filled with pure deuterium or a deuterium-tritium mixture as a
working gas. A very short duration of the neutron pulse, as well as its high brightness and mono-
chromaticity allows using time-of-flight methods with bases of about few meters to distinguish
signalsfromneutronsscatteredbydifferentelements.
ResultsoftheMonteCarlosimulationsofthescatteredneutronfieldfromseveralcompounds
(explosives and everyday use materials) are presented. The MCNP5 code has been used to get 2
information on the angular and energy distributions of neutrons scattered by the above mentioned
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compoundsassumingtheinitialneutronenergiestobeequalto2.45MeV(DD)and14MeV(DT).
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A new input has been elaborated that allows modeling not only a spectrum of the neutrons scat-
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tered at different angles but also their time history from the moment of generation up to the de-
tection. Such an approach allows getting approximate signals registered by hypothetic scintil-
lator+photomultiplerprobesplacedatvariousdistancesfromthescatteringobject,demonstrating J
principalcapabilityofthemethodtoidentifyanelementalcontentoftheinspectedobjects. Theex-
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tensivecomputationsreveledalsoseverallimitationsoftheproposedmethod,namely: lownumber
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ofneutronsreachingdetectorsystem,distortionsandinterferencesofscatteredneutronsignalsetc.
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Furthermore,preliminaryresultsoftheMCNPmodelingofthehiddenfissilematerialsdetec-
tionprocessarepresented. T

KEYWORDS: Detectionofexplosives;Detectionofcontrabandanddrugs;Neutrondetectors(cold, 7
thermal,fastneutrons)

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Contents
1 Introduction 1
2 Themethod 1
3 MCNPmodelingofthemethod 3
3.1 Modellingoftheneutronscatteringfromsimpleobjects 3
3.2 Morerealisticcase-modelingofaluggage 6
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3.3 Modelingofsignalsfromobjectsplacedinarow 7
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4 Detectionofhiddenfissilematerials,Monte-Carlosimulation 8
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4.1 Spectraofscatteredneutrons 8
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4.2 Modelingofscatteredneutronssignalsdetectedbytheneutronprobes 10

5 Conclusions 11 J
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1 Introduction
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A new approach to the detection of explosives and other illicit materials was proposed in [1, 2]. T
Taking advantage of the capabilities of modern neutron generators (based on the Plasma-Focus
principle)thatarecapabletoproduceflashesofveryintense(upto109 of2.45MeVneutronsfrom
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DD and up to 1011 of 14MeV neutrons per shot from DT reaction) and very short neutron pulses

(<10ns),itispossibletodetermineelementalcontentofunknownbulksamplesfrominformation
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existinginafieldofscatteredneutrons. Duetoshortneutronpulsedurationatime-of-flightmethod
canbeinvolvedintheidentificationprocedure. 0
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2 Themethod
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Themethodisbasedonthewellknowfactthatnuclide-specificinformationispresentinthescat- 0
tered neutron field. By detecting neutrons elastically and in-elastically scattered at different labo- 6
ratoryanglesfortwodifferentincidentneutronenergies(2.45MeVand14MeV),theamountsand
positionsofthescatteringnuclidesmaybedetermined(figure1).
Scattering signatures of different elements (especially H, C, N and O) should be precisely
measured and a data basis of such signatures established. Then, using the data basis, scattering
signaturesmeasuredforunknownsamplesareunfoldedtodeterminetheirelementalcomposition.
The method proposed belongs to the wider group of approaches that make use of specific
interactionofneutrons(fastorthermal)withdifferentmaterials. Asaresultofsuchinteractionan
inducedgammaradiationisemittedfromanobjectirradiatedaswellasafieldofscatteredneutrons
appears(duetoelasticandinelasticscatteringofprimaryneutrons). Theinformationonelemental
composition of the object can be drown from both the gamma radiation and the scattered neutron
field[3]–[7].
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Figure1. Theschemeillustratingideaoftheproposedmethod.
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Figure2. Schemeofthe“singleshot”detectingsystem.
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Weproposetobringintoplayaneutronsourcebasedonaplasmaaccelerator. whichgenerates
verypowerfulpulsesofneutronsinthenanosecondrangeduration. NeutronsourcesofthePlasma
Focus type can generate neutron pulses with durations in the nano-second range, and provide a
veryhighneutronyieldinthesepulses.
For example our device PF-6 (operating at the Institute of Plasma Physics and Laser Micro-
fusion, Warsaw, Poland) with 7.4kJ of energy in its capacitor storage, is capable to generate in
one pulse of ∼=10ns duration up to 109 DD (2.5MeV) neutrons or 1011 DT (14MeV) neutrons.
This feature allows to create a “single-shot” detection system. It means that all necessary infor-
mation will be received using a limited number of very bright pulses of neutrons having duration
in a nanosecond range and registered by means of the time-of-flight technique. A proposal of the
generalschemeofsuchdetectionsystemispresentedinfigure2.
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Figure3. ThegeometryoftheMCNPcalculation(R : source-objectandR : object-detectordistances).
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3 MCNPmodelingofthemethod
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TheMCNP(version5)[8]codehasbeenusedtoinvestigatevariousfeaturesandpropertiesofthe
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method. The complexity of the input-files increased together with increasing knowledge of the
team. The most important progress was the achievement of the capability of simulating scattered N
neutronsignalsasregisteredbyfactiousscopes(time-amplitudesignals). S
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3.1 Modellingoftheneutronscatteringfromsimpleobjects

In the first step the MCNP code was used to simulate scattering of neutrons from simple objects
(spheres with radius = 5cm) made of basic elements like Oxygen, Nitrogen, Carbon, Sulphur 7
as well as some compounds e.g. explosives (RDX) and everyday use materials like melamine,
glucose and acetamide. The aim of these investigations was to examine the dependence of the
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registered neutron signals on angles and distances: neutron source-sample, sample-detector etc.
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TheneutronpulsefromthepointDDsource(E =2.45MeV)wasassumedtobeGaussianintime
n
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withtherealisticfullwidthathalfmaximum(FWHM)of10ns. Thegeometryofthecomputation
ispresentedinfigure3. 0
Results of the computations performed using the geometry presented in figure 3 have been 0
alreadypublishedin[9]. Herewepresentonlysomeofthemconnectedwiththechoiceofascat-
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teringangle,theimportantfactorforthecapabilityofthesystemtodeterminetheelementalcontent
oftheinvestigatedcompound. Infigure4,signalsweredetectedwhiletheinitial2.45MeVneutron
pulse interacts with the investigated object (a sphere filled with the RDX explosive material) in a
geometrycorrespondingtotheonepresentedinfigure3.
The following conclusions can be drawn from the basic investigations with the use of the
simplegeometryshowninfigure3:
1. Capabilityofthesystemtodistinguishesignalscorrespondingtoneutronsscatteredbydiffer-
entelements(C,N,O)dependsstronglyonthescatteringangle. Fromtheresultspresented
infigure4itisevidentthatratherhighscatteringangles150◦–170◦ (practicallybackscatter-
ing)shouldbeusedforthedeterminationoftheelementalcontentofunknownobjectsasfor
loweranglesthesignalsoriginatedfromvariouselementsmergegradually.
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