Association Euroatom – IPP.CR Nuclear Physics Institute Řež _________________________________________________________________________________________________ NPI Experimental Activities on IFMIF Neutronics IEA International Workshop on Fusion Neutronics (23 rd 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

, VeniceIEA IACP NG2 target station negative ions, H (-) MeV (20 μA), D( - ) MeV (10 μA) NG1 target station positive ions protons MeV deuterons MeV 3,4He-ions MeV U-120M variable-energy cyclotron K=40 two-mode of acceleration NPI cyclotron-based Fast Neutron Facility

, VeniceIEA IACP neutron transport benchmark tests (IFMIF-like spectrum) NG1 target station: source reaction 3 He+D 2 O E( 3 He) 40 MeV Ēn 14.1 MeV En ≤ 33.0 MeV FWHM 15 o well simulate d-Li source spectrum

, VeniceIEA IACP Ep 37 MeV Ēn 13.9 MeV En ≤ 33.0 MeV FWHM 40 o Yn 4.4 x n/sr/s/μA Φn ≤ 3 x10 11 n/cm 2 /s (5mm distance from the target) NG2 target station: source reaction p+D 2 O activation benchmark tests (IFMIF-relevant energies)

, VeniceIEA IACP Ed 17 MeV Ēn 8.3 MeV En ≤ 20 MeV FWHM 22 o Yn 3.1 x n/sr/s/μA Φn ≤ 2 x10 11 n/cm 2 /s (5mm distance from the target) NG2 target station: source reaction d+D 2 O activation benchmark tests (fusion-relevant energies)

, VeniceIEA IACP 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

, VeniceIEA IACP 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 20 o ) ■ scintillation detector + pulse height technique ■ computational analysis at FZK (MCNP code and detailed three-dimensional geometry model of experiment ► good agreement observed for INPE/FZK evaluation ► LANL-150 data overestimates calculations by up to 50% above 15 MeV

, VeniceIEA IACP 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) ► computational analysis is under way at FZK

, VeniceIEA IACP 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 analysis M C DeLi (semi-empirical d-Li model) M C DeLicious (evaluated d+ 6,7 Li cross-section data) MCNPX (ISABEL (intra-nuclear cascade model) ► M C DeLicious 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+ 6,7 Li cross-section database needed

, VeniceIEA IACP Experimental verification of D-Li neutron yield at 17 MeV (TW3-TTMI-003/D6) ■ 7 Li(d,n) reaction at 17.1 MeV (eight angles) first time data on double-differential cross-section (DDCS) M C DeLicious 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+ 6,7 Li database

, VeniceIEA IACP Activation experiment on CuCrZr at energies below 20 MeV (Underlying Technology 2003) ■ 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)

, VeniceIEA IACP Activation experiment on Eurofer-97 IFMIF-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 (A sp ) at the end of irradiation in Bq/kg of Eurofer-97 determined 37 MeV protons D 2 O Target (Ř30×26 mm 2 ) Activation Foils 1.7 mm47 mm ► Resulting 22 activation products present the first integral benchmark data for the Eurofer steel at IFMIF-relevant neutron energies

, VeniceIEA IACP Activation experiment on Eurofer-97 Study of p-D2O neutron source spectrum ■ 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/r 2 law) ►correct calculations needed ■ due to identified discrepancy in LA-150h, MCNPX failed to represent the p+D 2 O source spectra ►spectral flux constructed by combining the measured and calculated (MCNPX) data and normalized by the 24 Na activity (Al monitoring foils).

, VeniceIEA IACP Comprehensive analysis performed at FZK by S.P.Simakov, [Workshop on Activation Data, Prague, June 2004, CD] Activation experiment on Eurofer-97 the activation analysis ■ 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)

, VeniceIEA IACP 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

, VeniceIEA IACP 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