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Implementation of an analytical model accounting for sample Implementation of an analytical model accounting for sample

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Implementation of an analytical model accounting for sample - PPT Presentation

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

sample model capture transmission model sample transmission capture neutron jrc validation powder schillebeeckx irmm size nuclear nrd resonance gelina

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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).