Effect of irradiation with 32-MeV protons on critical parameters of modern Nb$_{3}$Sn-based superconducting composite wires

Vibrating-sample magnetometry techniques has been used for investigation of the electrophysical characteristics of several types of modern commercial multistrand composite wires based on Nb$_{3}$Sn superconducting compound at temperatures that were measured 4.2, 7, and 12 K in magnetic fields up to 8 T before and after irradiation of the samples by fast (32-MeV) protons to fluences values 3 × 10$^{16}$, 1 × 10$^{17}$, 3 × 10$^{17}$, and 1 × 10$^{18}$ cm$^{–2}$. All samples irradiated to fluences values up to 1 × 10$^{17}$ cm$^{–2}$ exhibited growth of the critical current density, which was most sharply pronounced in strong magnetic fields at lower temperatures. Further irradiation to a fluence value of 1 × 10$^{18}$ cm$^{–2}$ led to decrease of the critical current density below the initial level. The critical temperature of samples monotonically decreased with increasing irradiation dose.