Relevance of various neutron sources to fusion-reactor radiation effects

Primary-recoil spectra, damage-energy spectra, and rates for (n,2n), (n,p), and (n,α) reactions were calculated for niobium exposed to several neutron environments. Neutrons from the 9Be(d,n) reaction introduce defects with qualitative similarities to those produced by a D-T fusion reactor. Low-energy neutrons such as those present in the core of EBR-II induce neither high-energy primary recoils nor significant transmutations.