IFMIF d-Li neutron source: Status of codes and nuclear data S.P. Simakov Institut für Reaktorsicherheit, Forschungszentrum Karlsruhe IEA Neutronics Meeting, October 2001 Baden-Baden, 18 October 2001

2 Area/Motivation/Aim International Fusion Material Irradiation Facility (IFMIF) is an accelerator driven d-Li intense neutron source for the irradiation of fusion relevant materials The accuracy of the assessed induced radiation effects will depend on the prediction quality of the spectral and angular neutron yield from the Li-target Aim of researches: -developing the computational procedure (M C DeLicious) for the generation of d-Li source term making use of evaluated d + 6,7 Li cross- section data -checking the M C DeLicious code against available experimental data -intercomparison M C DeLicious with M C DeLi and MCNPX, both of which use built-in analytical models for the Li(d,xn) reaction.

3 IFMIF: Principal overview

4 Basic Nuclear Processes in Li target, HFTM & Reflector Beam direction vi e w Elevation v i ew 3d v i ew EF = Eurofer: 89%Fe, 9%Cr, 1.1%W,0.4%Mn...

5 Methods/Codes/Computing Method: Monte Carlo (sampling independently each event/cascade starting from d + ) Codes description: M C DeLi M C DeLicious MCNPX(2.1.5) - dual d + -beam configuration + + ? - d + slowing down in Li d + Li cross sections model: Semi-empir.formula INPE Eval.File INC (only Li+d => n) ( 6,7 Li+d => n, γ,p,α..) (Li + d => n) - n- and γ- transport MCNP-4B MCNP-4C MCNP-4B Recently a newly evaluated d-Li data library in Institute of Nuclear Power and Engineering, Obninsk (INPE) in collaboration with FZK: –deuteron energies up to 50 MeV, –calculation models: diffraction theory and a modified cascade evaporation, –evaluated quantities: double differential cross sections of the cumulative particle yields (d,xn), (d,x  ), (d,x  ), etc. Processing from ENDF (evaluated data) to ACE (for MCNP) format: –NJOY 99

6 Basic Nuclear Process: Deuteron slowing down in Li-target MCDeLicious & MCNPX codes results:

7 Basic Nuclear Process: Deuteron-Lithium interaction (new eval. data) Table 1. Li + d reactions channels, Q values and thresholds. Reaction Channels for d-Li interaction

8 Source Model Verification: n - yield from thick Li-target bombarded by d + Table 1. Li + d reactions channels, Q values and thresholds. Total & Forward YieldsAngular n-Yield Spread of experimental data & uncertainty resulted from Li(d,xn) source modelling amount dozens-hundreds percents, INPE evaluation should be improved

9 Source Model Verification: n - yield from thick Li-target bombarded by d + Table 1. Li + d reactions channels, Q values and thresholds. Forward Average Neutron Energy Spread of experimental data & uncertainty resulted from Li(d,xn) source modelling amount dozens-hundreds percents, INPE evaluation should be improved

10 Source Model Verification: n-yield from thick Li-target bombarded by d + Table 1. Li + d reactions channels, Q values and thresholds. Energy-angle differential neutron yield at E d = 32 MeV M C DeLicious with INPE d-Li evaluated data is more successeful then M C DeLi and MCNPX

11 Source Model Verification: n-yield from thick Li-target bombarded by d + Table 1. Li + d reactions channels, Q values and thresholds. Energy-angle differential neutron yield at E d = 40 MeV M C DeLicious with INPE d-Li evaluated data is more successeful then M C DeLi and MCNPX

12 Source Model Verification: γ-yield from thick Li-target bombarded by d + Table 1. Li + d reactions channels, Q values and thresholds. Energy differential  -yield at E d = 40 MeV M C DeLicious with INPE d-Li evaluated data is capable to predict the photon yield  -yield Sources: primary process - Li(d,x  ) secondary process - Li(n,x  ) Total & Forward  - Yield

13 Conclusions Deuteron bombarded thick Li-target yield experimental data has been compiled: –neutron production: scattering of the original data is relatively large (  50%), –photon production: no data available, –there is need for further measurements. Code M C Delicious has been developed which makes use of the d-Li cross section library evaluated in INPE: –M C DeLicious predicts the neutron yield better then M C DeLi & MCNPX do, –it also is capable to predict the production of photons and charged particles, –further improvements of IFMIF source parameters could be now easily accomplished as soon as updated d-Li libraries become available.