Fusion-neutron damage in superconductors and magnet stabilizers

Two NbTi and two Cu wires were irradiated with 14.8 MeV neutrons at 4.2 K to fluences of 6 to 8 x 1020 n/m2, using RTNS-II. Electrical resistances of Cu were monitored during irradiation. Magnetoresistances were measured in fields up to 12.4 T before and after irradiation and after isochronal annealing up to 273 K. Critical currents of NbTi were measured after irradiation, in feilds up to 10 T. The initial rate of increase of resistivity of the Cu was found to be 2.23 x 10-31 (Ω-m)/(n/m2). This rate could be predicted from fission reactor irradiations using damage energy scaling. The maximum observed change in the NbTi critical was a decrease of 3% at 4 T. At 6, 8, and 10 T there were no significant changes