Investigation of neutron and photon flux spectra in a streaming mock-up for ITER

A neutronics mock-up of the International Thermonuclear Experimental Reacto r (ITER) inboard shielding system with streaming path for the fusion neutro ns was investigated in order to validate the design. Neutron and photon flu x spectra were measured at several positions in the assembly. The experimen tally determined flux spectra are analysed with the ITER design tools Monte Carlo code MCNP-4A and Fusion Evaluated Nuclear Data Library FENDL-1 and F ENDL-2. Helium production, radiation damage and photon heating rates, which are design parameters of the shielding system are derived from both, the m easured and the calculated spectral fluxes. (C) 2000 Elsevier Science B.V. All rights reserved.