CALCULATION OF DISPLACEMENT, GAS, AND TRANSMUTATION PRODUCTION IN STAINLESS-STEEL IRRADIATED WITH SPALLATION NEUTRONS

Calculations using the high-energy transport code LAHET have been made for the production of displacements, helium gas, and transmuted atoms for stainless steel (Fe-18 wt% Cr-10 wt% Ni) irradiated with spallati on neutrons at energies of 100 to 1600 MeV. The damage energy cross se ction increased from about 250 to 350 b keV for increasing neutron ene rgies from 100 to 1600 MeV with a spallation spectrum average of 281 b keV. For a displacement threshold energy of 33 eV, the corresponding spectrum-average displacement cross section is 3400 b. The PKA spectru m was found to be fairly independent of the incident neutron energy, w ith an average damage energy of 0.25-0.30 MeV. The helium production c ross section increased monotonically with increasing neutron energy, w ith a spectrum average of 0.32 b. The maximum transmutation yield was observed near manganese (Z = 25), corresponding to a production cross section of about 0.2 b. Relevance to fusion materials is discussed.