K Kauwenberghs EC JRC IRMM Standards for Nuclear Safety Security and Safeguards SN3S Introduction EC JRC IRMM Neutron Resonance Transmission and Capture Analysis Motivation Initial model validation ID: 318150
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Slide1
Implementation of an analytical model accounting for sample inhomogeneities in REFIT
K. KauwenberghsEC – JRC – IRMMStandards for Nuclear Safety, Security and Safeguards (SN3S)Slide2
Introduction (EC - JRC- IRMM)Neutron Resonance Transmission and Capture AnalysisMotivationInitial model validationExperimental model validation Summary
OutlineSlide3
JRC-IRMM major provider in Europe of ND for nuclear energy applications
GELINA
VdG
EC - JRC – IRMM
neutron facilitiesSlide4
GELINA
Van de Graaff
White neutron source
+
Time-of-flight (TOF)
99
Tc(n,
) cross section
Mono-energetic neutrons
(cp,n) reactions
EC - JRC – IRMM
neutron facilitiesSlide5
Pulsed white neutron source
(10 meV < En < 20 MeV)High resolution TOF measurements
Multi-user facility: 10 flight paths
Flight
path
lengths
: 10 m – 400m
Measurement stations with special equipment to perform:
Total cross section measurements
Partial cross section measurements
FLIGHT PATHS SOUTH
FLIGHT PATHS NORD
ELECTRON LINAC
TARGET HALL
Mondelaers and Schillebeeckx, Notizario 11 (2006) 19
EC - JRC – IRMM
GELINASlide6
e
-
accelerated to E
e-,max
≈ 140 MeV
Bremsstrahlung in U-target
(
rotating & cooled with liquid Hg)
(
, n
) , (
, f ) in U-target
Low energy neutrons by moderation (water moderator in Be-canning)EC - JRC – IRMMGELINASlide7
Neutron Resonance Transmission
and Capture AnalysisCapture
Transmission
T : transmission
Fraction of the neutron beam traversing the sample without any interaction
Y
: capture yield
Fraction of the neutron beam creating a (n,
) reaction in the sampleSlide8
Capture
Transmission
Schillebeeckx et al., Nuclear Data Sheets 113 (2012) 3054 - 3100
Neutron Resonance Transmission
and Capture AnalysisSlide9
Capture
Transmission
Schillebeeckx et al., Nuclear Data Sheets 113 (2012) 3054 - 3100
Neutron Resonance Transmission
and Capture AnalysisSlide10
Sample out
Sample in
Schillebeeckx et al., Nuclear Data Sheets 113 (2012) 3054 - 3100
Neutron Resonance Transmission
and Capture AnalysisSlide11
Motivationgood geometry + homogeneous sample
R(
t
m
,E
) response of TOF-spectrometer
REFIT, M.
Moxon
241
Am
Schillebeeckx et al., Nuclear Data Sheets 113 (2012) 3054 - 3100Slide12
Ignoring sample
inhomogeneities
:
Underestimation of
s
peak
Overestimation of
G
G
Motivationheterogeneous sampleSlide13
Transmission + Capture data sample properties
resonance parameters
Motivation
good geometry + homogeneous sampleSlide14
Expected transmissionHomogeneous sample:Heterogeneous sample:
p(n') : distribution of areal density
1cm
From H. Uetsuka, et al., “Gamma Spectrometry of TMI-2 Debris” (written in Japanese), JAERI-Research 95-084.
Motivation
heterogeneous sampleSlide15
Analytical models to account for inhomogeneities of a powder sample:Kopecky et al. (ND2007)LP Model (Levermore, Pomraning
et al., J. Math. Phys. 27, 2526, 1986)…Comparison with transmission spectra produced by stochastic calculations (MC simulations)LP model performs the best
35
th
ESARDA 2013
Becker et al., "Particle size inhomogeneity effect on NRD"
Initial model validationSlide16
35
th ESARDA 2013Becker et al., "Particle size inhomogeneity effect on NRD"
Initial model validation
Kopecky
et al.:
Macroscopic
model to describe the variation of the thickness
Kopecky
et al.,
ND2007 , Nice , pp. 623 – 626; Schillebeeckx et al., NDS 113 (2012) 3054 - 3100 LP Model:Microscopic modelLevermore, Pomraning et al., J. Math. Phys. 27, 2526, 1986
Slide17
Experimental validation of the model = based on capture and transmission measurements at GELINA:
Cu powder samples with known grain size distributionW powder samples with known grain size distribution
35
th
ESARDA 2013
Becker et al., "Particle size inhomogeneity effect on NRD"
Experimental model validationSlide18
54
th INMM 2013Schillebeeckx et al., "Contribution of the JRC to the development of NRD"
nat
W
-metal disc
(80 cm diameter, 14 g
nat
W
)
nat
W
-powder mixed with natS-powder(80 cm diameter, 14 g natW, 3.5 g natS)
Experimental model validationSlide19
nat
W-metal disc (80 cm diameter, 14 g natW)
54
th
INMM 2013
Schillebeeckx et al., "Contribution of the JRC to the development of NRD"
Experimental model validationSlide20
nat
W-powder mixed with natS-powder(80 cm diameter, 14 g natW, 3.5 g natS)
54
th
INMM 2013
Schillebeeckx et al., "Contribution of the JRC to the development of NRD"
Experimental model validationSlide21
Model accounting for inhomogeneities of a powder sample is implemented in REFITInitial
validation of possible models with MC simulations LP Model performs the bestExperimental validation of the model with capture and transmission measurements at GELINA W powder samples with known grain size distribution
SummarySlide22
Contributors:
B. Becker, F. Emiliani, S. Kopecky, P. Schillebeeckx EC – JRC – IRMM, Geel (B)
H. Harada F.
Kitatani
, M. Koizumi, H. Tsuchiya
JAEA, Tokai-
mura
(Japan)
Acknowledgement
:
This work was supported by the European Commission within
the Seventh Framework Programme through ERINDA (FP7 – 269499).