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Association Euroatom – IPP.CR Nuclear Physics Institute Řež_________________________________________________________________________________________________

NPI Experimental Activities 2003-5 on IFMIF Neutronics

IEA International Workshop on Fusion Neutronics (23rd Symposium on Fusion Technology - SOFT)

September 21, 2004, Venice

P. Bém, V.Burjan, M.Götz, M.Honusek, V.Kroha, J.Novák E.Šimečková Nuclear Physics Institute Řež, CR

U. Fischer, U.v. Möllendorff, S.P. Simakov, FZ Karlsruhe B. Esposito, ENEA Frascati R.A. Forrest, UKAEA Culham J. Kopecky, JUKO Research

221.09.2004, Venice IEA IACP

NG2 target stationnegative ions, H(-) 18-37 MeV (20 μA), D(-) 11-18 MeV (10 μA)

NG1 target stationpositive ionsprotons 18-24 MeV deuterons 11-17 MeV3,4He-ions 20-40 MeV

U-120Mvariable-energy cyclotron K=40 two-mode of acceleration

NPI cyclotron-based Fast Neutron Facility


neutron transport benchmark tests (IFMIF-like spectrum)

NG1 target station: source reaction 3He+D2O

0 5 10 15 20 25 30 35

107

108

109

[d(32MeV) + Li] x 0,015

[d(40MeV) + Li] x 0,015

3He (40MeV) + D2O

Spec

tral

Neu

tron

Yie

ld [

n/sr

/Mev

/C

]

Neutron Energy [MeV]

E(3He) 40 MeV

Ēn 14.1 MeV En ≤ 33.0 MeV FWHM 15o

well simulate d-Li source spectrum


Ep 37 MeV

Ēn 13.9 MeV En ≤ 33.0 MeVFWHM 40o

Yn 4.4 x 1010 n/sr/s/μA Φn ≤ 3 x1011 n/cm2/s (5mm distance from the target)

0 10 20 30 40107

108

109

1010

D2O (p,xn)

0o

20o

40o

Sp

ectr

al N

eutr

on Y

ield

[ n

/sr/

MeV

/C

]


0o

37 MeV

24 MeV

NG2 target station: source reaction p+D2O

activation benchmark tests (IFMIF-relevant energies)


Ed 17 MeV

Ēn 8.3 MeV En ≤ 20 MeVFWHM 22 o

Yn 3.1 x 1010 n/sr/s/μA Φn ≤ 2 x1011 n/cm2/s (5mm distance from the target)

NG2 target station: source reaction d+D2O

0 10 20 30 40107

108

109

1010

10 deg 20 deg 40 deg

Sp

ectr

al N

eutr

on Y

ield

[ n

/sr/

MeV

/C ]


Ed = 17.1 MeVD

2O (d,xn)

0 deg

activation benchmark tests (fusion-relevant energies)


1 - U-120M cyclotron, 2 - beam guide and vacuum system, 3 - beam-diagnostic hardware 4 - quadrupole lenses 5 - beam-guide support 6 - target chamber of cooled heavy- water flow 7 - holder for irradiated samples

NG2 station: heavy-water target

■ negative-ion mode of acceleration (37 MeV protons, 18 MeV deuterons) ■ up to 20 μA, stable long-term operation at ≤ 5% fluctuation ■ flowing heavy-water target (beam-power dissipation up to kW) ■ collimator free beam-guide (no false neutron source) ► suitable for neutron activation experiments


Neutron transport benchmark on iron IFMIF-like spectrum (TW3-TTMN-002, D6)

■ iron (the main constituent of the IMIF high-flux test module) ■ INPE/FZK evaluation- and LANL-150 iron data libraries■ 20 cm thick iron slab (0 and 20o)■ scintillation detector + pulse height technique ■ computational analysis at FZK (MCNP code and detailed three-dimensional geometry model of experiment0 5 10 15 20 25 30 35

10-3

10-2

10-1

Fe cylindrical slab (20 cm) irradiated with

D2O(3He,xn) source spectrum (40 MeV 3He)

= 20o

Experiment NPI Rez MCNP FZK/INPE-50 MCNP LANL-150

Spec

tral

Neu

tron

Yie

ld,

10

8 n/s

r/M

eV/

C

Neutron Energy, MeV

► good agreement observed for INPE/FZK evaluation► LANL-150 data overestimates calculations by up to 50% above 15 MeV


Neutron transport benchmark on iron IFMIF-like spectrum (TW3-TTMN-002, D6b)

■ to account for the inelastic- scattering of neutrons ■ upgraded scintillator-detector hardware and double-conical neutron collimator assembly utilized ■ neutrons reliably determined above 0.7 MeV (twofold extending of energy range compared to previous data)

1 10105

106

107

108

109

Spec

tral

Neu

tron

Yie

ld [

n/sr

/MeV

/C

]


Fe-disk d80shielded detector

Fe-disk

D2O( 3He,xn) source

Fe-disk d40collimated neutron beam

► computational analysis is under way at FZK


0 5 10 15 20 25 30 3510-4

10-3

10-2

10-1

100

Neutron Energy, MeV

MCNPX

Bem et al. (2003)

Ed = 17 MeV, = 0o

McDeLicious

Spec

tral

Yie

ld,

10

10 n

/sr/

MeV

/C

Experimental verification of D-Li neutron yield at 17 MeV (TW3-TTMI-003/D6)

■ Li(d,xn) reaction, thick target energy spectra at 17.1 and 16.3 MeV (five angles)

■ computational analysisMCDeLi (semi-empirical d-Li model) MCDeLicious (evaluated d+6,7Li cross-section data) MCNPX (ISABEL (intra-nuclear cascade model)

► MCDeLicious predicts thick-target yield spectra + angle-dependent yield observables► all models fail to reproduce the structure of higher energy tail of spectra ► further revision of the d+ 6,7Li cross-section database needed


1 100,01

0,1

1

10

100

DD

CS

[mb/

sr/M

eV]


= 15°

7Li(d,xn), Ed=17.1 MeV

Td=1.4 MeV

MCDeLicious,E

d=16.5 MeV

Experimental verification of D-Li neutron yield at 17 MeV (TW3-TTMI-003/D6)

■ 7Li(d,n) reaction at 17.1 MeV (eight angles) first time data on double-differential cross-section (DDCS)

MCDeLicious code ■ described well the deuteron break-up and compound nucleus excitation processes (low energy region) ■ fails to reproduce the structure corresponding the excitation of *Be

► present and recently published Tohoku University data on DDCS will be used at FZK to updating the d+ 6,7Li database


Activation experiment on CuCrZr at energies below 20 MeV (Underlying Technology 2003)

Na

24

Cr5

1

Mn

56

Co

61

Co

62

m

Ni6

5

Cu

64

Zr8

9

Zr9

5

0,1

1

Ca

lc.

/ E

xpt.

4

NPI d-BeTUD d-T

■ samples activated in the d+Be neutron source (consistency with previous investigations at FZK) ■ 9 activation products determined

■ C/E analysis by the Fispact code (with EAF 2003 data library)

► results agree with activation data from TUD (d+T neutron source)► indicate the need for investigation of discrepancies in the activation cross-section data ► further analysis in terms of upgraded EAF (improved model TALYS) is under way (R. A. Forrest)


Activation experiment on Eurofer-97IFMIF-like spectrum (TW3-TTMN-002, D6a)

■ the first activation experiment for Eu-97 steel in a white neutron field extending to 32 MeV ■ motivation: validation of IEAF-2001 cross-section data a continuation of activation experiments on SS-316 and F82H steels and vanadium alloys in FZ Karlsruhe ■ two independent runs (source-to-sample distance of 1.7 and 47.1 mm) ■ activated samples investigated by HPGe at 11 cooling times (from 0.5 to 102 days) ■ specific activities (Asp) at the end of irradiation in Bq/kg of Eurofer-97 determined

37 MeV protons

D2O Target(Ř30×26 mm2)

Activation Foils

1.7 mm 47 mm

► Resulting 22 activation products present the first integral benchmark data for the Eurofer steel at IFMIF-relevant neutron energies


10 1001E8

1E9

1E10

1E11p(37MeV) + D2O

Neu

tron

Flu

x [n

/µC

.cm

2 ]

x [mm]

27Al(n,)

24Na

d 20d 10 d 0

FZK[d(40MeV) +Li]5x5

Activation experiment on Eurofer-97Study of p-D2O neutron source spectrum

0 5 10 15 20 25 30 3510-3

10-2

10-1

100

p + D2O, E

p = 36 MeV

Rez Experiment

Neutron Energy, MeV

MCNPX/LA-150

= 0o

MCNPX/Model

Spec

tral

Neu

tron

Yie

ld,

1010

n/s

r/M

eV/

C

■ source spectra are measured at large distance (point-like geometry, PLG) ■ due to space and energy integration over target and foil dimensions the set-up can not be considered as the PLG (neutron flux dependence on distance does not follow 1/r2 law) ►correct calculations needed

■ due to identified discrepancy in LA-150h, MCNPX failed to represent the p+D2O source spectra

►spectral flux constructed by combining the measured and calculated (MCNPX) data and normalized by the 24Na activity (Al monitoring foils).


Comprehensive analysis performed at FZK by S.P.Simakov,

[Workshop on Activation Data, Prague, June 2004, CD]

Activation experiment on Eurofer-97the activation analysis

Na

24Sc

46

Sc 4

7Sc

48

V 4

8C

r 48

Cr

51M

n 52

Mn

54M

n 56

Fe 5

2Fe

59

Co

56C

o 57

Co

58C

o 60

Ni 5

7H

f 18

0mT

a 17

7T

a 18

0T

a 18

2T

a 18

3T

a 18

4W

18710-3

10-2

10-1

100

101

Distance from the D2O Target 47mm

C/E

Distance from the D2O Target 1.7mm

■ the activities in the Eu-97 steel predicted by the ALARA code with IEAF-2001 fail

■ the C/E ratios calculated for samples irradiated at 1.7 and 47.1 mm distance reasonably agree each other (proving experimental consistency)

► reasonable agreement found for half of the detected radio-nuclides ► large discrepancies for the others necessitate updating of the relevant IEAF-2001 cross sections (usually rely on theoretical model considerations not yet backed by cross section measurement for En above 15 MeV)


Current and next program

IFMIF white spectrum: Activation experiment on Tungsten (TW4-TTMN-002, D6, 2004) on Tantalum (TW5-TTMN-002, D6, 2005)

► continuing program of first time activation at IFMIF relevant energies► currently, W samples were irradiated, 15 activation products are investigated by two HPGe detectors► pre- and post- C/E analysis with the ALARA inventory code has been and will be done at FZK► neutron spectrum at the sample position will be determined by MCNP model calculations combined with experimental data from multi-foil activation-, scintillation- and proton-recoil spectrometry technique (1) to calibrate absolutely the spectral flux at sample position and (2) to renormalize previous activation experiments on Eu-97


Current and next program

Activation cross-section measurement (Underlying Technology 2005)

► development and testing the p(20-37 MeV) + Li (thin target) monoenergetic neutron source on the NG2 target station (high-current proton beam)► neutron spectrum from p+Li source at the sample position will be determined by MCNP model calculations combined with experimental data from multi-foil activation-, scintillation- and PRT technique ► to extend the EASY database above 20 MeV neutron energy for selected nuclides

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