1 Nuclear Physics Institute Řež Association EUROATOM – IPP/NPI.CR __________________________________________________________ Nuclear Data for the IFMIF, IAEA Technical Meeting Forschungszentrum Karlsruhe, October 4-6, 2005 NPI Cyclotron-based Fast Neutron Facility NPI team: P. Bém, V.Burjan, M.Götz, M.Honusek, V.Kroha, J.Novák, and E.Šimečková IFMIF collaboration: U. Fischer, U.v. Möllendorff, S.P.Simakov October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe EAF collaboration: R. Forrest, Ju. Kopecký

2 NPI variable-energy cyclotron U-120M NG1 target station fast neutron spectrometry scintillation detectors p-h unfolding technique SCINFUL-R code NG2 target station neutron activation HPGe detectors D(-) MeV (10 μA) H(-) MeV (20 μA) protons MeV (3 μA) deuterons MeV (3 μA) 3,4He-ions MeV (2 μA) negative-ion extractor positive-ion deflector neutron collimator October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe

3 Experimental verification of d+Li neutron yield /1 NG1 to validate model calculations to complete the data set the spectral yield of Li(d,xn) ■ thick target ■ incident energy of 17 and 16.3 MeV ■ angular distribution comparison to model predictions: ■ McDeLicious describes well the deuteron break-up and compound nucleus excitation processes ■ all models fail to reproduce the angular observables and high energy part of spectra ► updating of theoretical approach needed October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe

4 Experimental verification of d+Li neutron yield /2 NG1 ■ agreement of present data with TOF ■ disagreement of TOF data at 40 MeV ■ McDeLicious model fails to reproduce the structure of spectra corresponding to higher *Be states ■ Cross-sections data requested October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe

5 Experimental verification of d+Li neutron yield /3 NG1 measurement of the double differential cross section of 7 Li(d,n) reaction ■ straight-through target chamber ■ target changer & beam viewer ■ 7 Li-enriched metallic foils target ■ Faraday cup situated in shielded beam dump ■ scintillator detector situated in double-conical iron collimator & shielding placed on movable frame ■ BICRON liquid scintillator & bipolar-pulse/zero-crossing mode of n-γ discrimination ■ pulse-height unfolding technique: GRAVEL code & SCINFUL-R response function ■ dynamic range from 0.7 to 35 MeV by setting PMT supply (2200, 1850 and 1550 V) set-up of experiment October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe

6 ■ target chamber ■ cooled target holder with argon fillable "dog box" ■ 7 Li-enriched metallic foils 0.5 mm, 1.2 MeV /17 MeV ■ shielding of the Faraday cup (beam dump) ■ shielded scintillator detector ■ angular range θ ≥ 15 deg. Experimental verification of d+Li neutron yield /4 NG1 measurement of the double differential cross section of 7 Li(d,n) reaction wiew on the set-up of experiment October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe

7 ■ first DDCS data ■ data down to 1 MeV ■ angular distribution (eight angles) ■ well identified neutron group corresponding to 7 Li(d,n 0,1 ) 8 Be* reaction channels M C DeLicious code describes well the (d,np) and compound nucleus processes at low energy region ► present and recently published Tohoku University data on DDCS will be used at FZK to modify the McDeLicious model Experimental verification of d+Li neutron yield /5 NG1 measurement of the double differential cross section of 7 Li(d,n) reaction results October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe

8 ■ deuterons up to 18 MeV only ■ deuteron break-up by fast light-ions  □ high cross section □ foward-directed fast neutron emmision ■ 3 He( 40 MeV) + D 2 O(thick target) ■ investigated for the first time ■ scintillator detector, P-H unfolding technique) ■ the zero-degree spectral yield: □ mean energy of 14 MeV □ energy range up to 30.0 MeV □ compared with d+Li data (at IFMIF incident deuteron energies) ■ 3 He+D 2 O reaction wel simulates the d-Li neutron spectrum only facility within EU operating for IFMIF neutronics Simulation of IFMIF neutron spectrum /1 NG1 October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe

9 ■ angular distribution of integrated yield derived from measured spectral yield data ■ comparison to the d+Li (and d+Be) data shows ■ anglular observables of 3 He+D2O simulate the IFMIF source as well Simulation of IFMIF neutron spectrum /2 NG1 October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe

10 ■ iron selected as major constituent of IFMIF high-flux test cell ■ 3 He-beam of 5-100nA current ■ neutrons from 3 He + D 2 O source transmitted through iron slabs (20cm thick, cm in diameter) ■ scintillator-ph-unfolding technique ■ set of spectral-yield data at different angles ■ room background □ suppressed by detector shielding (set I) □ suppressed by collimator and/or by determined by shadow bare method (set II) Neutron transport benchmark on iron /1 NG1 October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe

11 Neutron transport benchmark on iron /2 ■ arrangement of transport experiment (set II) □ D 2 O target, □ iron sample of 40 cm in diameter □ shadow-bare (room-background test) □ unshielded NE-213 scintillator detector NG1 October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe

12 Neutron transport benchmark on iron /3. ■ set I data 80 cm iron slab, shielded detector ■ good agreement for INPE/FZK ■ an overestimation of LANL ■ MCNPX analysis (INPE/FZK evaluation- and LANL-150 iron data libraries) detail three-dimensional geometry model of experimental arrangements ■ set II data 40 cm slab, shadow-bare method to test the room-background effects to account for the inelastic-scattering the analysis is under way at FZK NG1 October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe

13 High-current beam line ■ negative-ion mode of acceleration ■ stripping-foil extractor ■ protons (900W / MeV) ■ deuterons (200W / MeV) ■ good beam-current stability suitable for neutron activation experiments ■ slit- free beam guide (neglectable contribution of false-neutron source in the vicinity of the primary source) ■ small beam spot (d ~ 3 mm FWHM) NG2 October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe

14 7 Li(C backing) target quasi-monoenergetic spectrum ■ set-up similar to design at INS Tokyo 2 mm thick 7 Li foil 12 mm thick graphit stopper DDCS of 7 Li(p,n) data Tohoku & CYRIC En = MeV ■ cooling by 5 o C alcohol stream beam-power of 600W reliably operated n/cm 2 /s calculated (in peak) for 30 MeV 20 μA proton beam at minimum t-s distance of 50 mm NG2 - high-power neutron target station Li-foil „dog box“ Li-target position October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe

15 D 2 O(d,xn) reaction ■ angular distribution investigated for the first time NE p.h.-unfolding zero-degree neutron emission (incident energy 17 MeV): ■ mean neutron energy 8.3 MeV ■ energy range up to 20 MeV ■ integral yield 3 x10 11 n/sr/s/10μA high-power neutron source ■ ITER relevant energies thick D 2 O target „white“ neutron spectrum investigated to replace toxic Be target Neutron energy, MeV Spectral yield, n/MeV/sr/mkC NG2 - high-power neutron target station October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe

16 D 2 O(p,xn) reaction proposed to simulate IFMIF spectrum ■ investigated for the first time NE p.h.-unfolding zero-degree neutron emission (incident energy 37 MeV): ■ mean neutron energy 13.9 MeV ■ energy range up to 33.0 MeV ■ integral yield 9x10 11 n/sr/s/20μA high-power neutron source ■ energies relevant to main part of IFMIF Spectral yield, n/MeV/sr/mkC Neutron energy, MeV 40 o 0o0o 20 o 0o0o NG2 experiment NG1experiment October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe NG2 - high-power neutron target station

17 D 2 O target station ■ heavy-water-stream target ( kW beam-power) ■ 8 operational parameters registered to control after-effects of micro-evaporation  electro-dissociation bubble-free operation Overview of the target station (quadropole triplet, beam-diagnostics, separated vacuum hardware & fallback system, target chamber, holder for irradiated samples) October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe NG2 - high-power neutron target station

18 (a)due to micro-evaporation and electro-dissociation  pressure compensators remotely controlled by TV set (ultrasonic-level indicator monitored by PC- in progress) beam density on input foil0.25 mA/cm 2 (0.5 for SPIRAL-2) volume0.064 cm 3 volume-heat dissipation6.3 kW/cm 3 (~ 20 for SPIRAL-2) flow velocity40 cm 3 s -1 (5 l overall volume) temperature5 to 22 o C (at 400 W beam power) T-gradient on the target2 o C (at 400 W beam power) pressure on the target3.0 bar D 2 O decrement (a) ~ cm 3 μA -1 s -1 cooling medium (alcohol)1-5 o C insulation resistance (FC)20 MΩ under operation N2 D 2 O target station, operation parameters NG2, Heavy-water target October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe

19 Neutron spectral flux at sample position NG2, p+D 2 O source reaction ■ primary source spectra are measured in PLG set of experiment PLG) ■ space and energy integration over target-foil dimensions the set-up can not be considered as PLG 37MeV proton beam D 2 O target Φ30x16 mm x x ■ Measured dependence of 27 Al(n,a) 24 Na reaction rate on the distance to the D 2 O target does not follow 1/r 2 law) October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe

20 Spectral flux at sample position ■ preliminary evaluated (NPI/NE) □ by combination of DDY data (NE-213) and MCNPX calculation □ resulting spectrum normalized to the integral flux determined by Al-foil activation □ Asp data from activation of Eu-97 steel-, W-, Ta-, and Cr- samples □ C/E analyzed preliminary by ALARA and FISPACT using (NPI/NE) ■ experimentaly determined (NPI/DF) □ set of DF with threshold reactions up to neutron energy of 36 MeV irradiated at various distances x from the target □ DF spectra obtained by SAND-II unfolding (upgraded at FZK) □ C/E reanalysis of Eu-97-, W-, Ta-, (Cr---) activation data ■ calibrated (benchmarked) DF-spectrum by PRT method □ proton radiator of PRT set-up located at some DF position October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe NG2, p+D 2 O source reaction, spectral flux at sample position

21 MCNPX simulation of flux □ data set far from complete □ CNPX fails to represent the p+D reaction spectra Spectral flux at sample position (NPI/NE) constructed by combining □ measured spectrum > 8 MeV, □ calculated (MCNPX) spectrum < 8 MeV □ normalization to calculated flux density using DF (Al foils) mesurement October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe NG2, p+D 2 O, spectral flux, preliminary evaluation

22 27Al(n,α) 24Na Y,Au(n,4n) Au,Co(n,3n) Au,Nb,Co,Y(n,2n) Ti(n,p) Ti,Al(n,α) b RR ratio, 3 / 165 mm Dosimetry-multifoil activation method ■ DF foils set (Al, Au, Bi, Co, Fe, Lu, Nb, Rh, Ti, Y, Zr) ■ samples irradiated at 3 and 156 mm distance from the D 2 O target ■ Asp of 27 threshold reactions determined by γ-spectrometry (calibrated HPGe detectors) for Eth up to 23 MeV and energy range up to 33 MeV ■ forward-to-backward RR ratios for different thresholds ■ indicate the variation of spectrum with distance October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe NG2, p+D 2 O, spectral flux, DF evaluation

23 Neutron spectral fluxes at 3.15 mm DF foils set (Al, Au, Bi, Co, Fe, Lu, Nb, Rh, Ti, Y, Zr) Neutron energy (MeV) ■ 27 threshold reactions ■ Asp data unfolded by SAND-code ■ black curve guess (input) spectrum (NPI/NE/3) ■ curve after 10th iteration presents NPI/DF/3 spectrum October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe NG2, p+D 2 O, spectral flux, DF evaluation, spectrum unfolding

24 Activation of Eurofer-97 in IFMIF-like spectrum C-to-E ratios NPI/NE spectrum ● ALARA / EAF-2001 ● FISPACT/ EASY-2005 NPI/DF spectrum ● FISPACT / EASY NPI experiment, p(37 MeV)+D 2 O source October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe NG2, p+D 2 O source

25 Activation of Tungsten in IFMIF-like spectrum NPI experiment, p(37 MeV)+D 2 O source C-to-E ratios NPI/NE spectrum ● ALARA / EAF-2001 ● FISPACT/ EASY-2005 NPI/DF spectrum ● FISPACT / EASY October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe NG2, p+D 2 O source

26 Neutron energy (MeV) ■ 27 threshold reactions ■ Asp data unfolded by SAND-code ■ black curve guess (input) spectrum (NPI/NE/156) ■ curve after 10th iteration presents NPI/DF/156 spectrum Neutron spectral fluxes at 156 mm DF foils set (Al, Au, Bi, Co, Fe, Lu, Nb, Rh, Ti, Y, Zr) October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe NG2, p+D 2 O, spectral flux, DF evaluation, spectrum unfolding

27 CH radiator ΔE-E detectors D 2 O target 156 mm from the target shadow bar ■ 1 H(n,p) reference reaction ■ recoil protons detected at well-defined geometry current tasks: ■ detection efficiency ■ response simulation ■ discrimination of spurious events (shadow-bar vs coincidence technique) ■ hydrogen radiator at some position of dF foils October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe ■ two Si E,ΔE detectors act as a telescope NG2, p+D 2 O, spectral flux, evaluation by PRT technique

28 October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe proton--recoil locus deuteron locus 7 Li(p,n), E p = 30 MeV CH 2 radiator Θ lab = 44 o 25 mg/cm MeV/14 MeV E+ E+ΔE ΔE FG(CH 2 )-BG(C) incident spectrum (TOF Tohoku) unfolded spectrum 7Li(p,n), 30 MeV proton recoil spectrum NG2, p+D 2 O, spectral flux, evaluation by PRT technique, shadow-bar test p- and α particles induced in Si detectors by neutrons penetrating the shadow-bar protons from PRT hardware and C seen by PRT solid angle ■ this part in FG – BG spectrum serves as a test provides test of correct background subtraction

29 Summary Present status of NPI FNF for neutron-activation program ■ p/d induced neutron source reactions, D 2 O- and 7 Li- targets operated ■ neutron fields of IFMIF relevant energies □ white spectrum: En ≤ 33 MeV, Φn ≤ 3x10 11 n/cm 2 /s spectral flux at foil position determined by DF method □ variable-energy (QME) spectrum, En = MeV, Φn ≤ 3x10 9 n/cm 2 /s ■ activation data on Eu-97, W and Ta related to the NPI/DF spectrum Next program ■ activation benchmark test on Cr (TW6-TTMN-D6) in NPI/DF spectrum ■ benchmarking of NPI/DF spectrum by PRT technique Proposed program experimental ACS (18-35 MeV) & benchmark tests (En ≤ 33 MeV) ■ data for IFMIF/EAF-relevant selection of nuclides ■ data for spectral-flux monitoring in IFMIF TC by DF technique October 4-6, 2005 ND for IFMIF, IAEA Technical Meeting, Karlsruhe