Damage to stabilizing materials by 400 GeV protons

A study of the radiation induced resistivity resulting from 400 GeV protons was made. The pulsed beam of the Fermi National Accelerator Laboratory was used with an intensity of 6×10¹²protons per pulse at 400 GeV with a slow spill of approximately 1 sec. The instantaneous irradiation rate on the sample is 1.5×10¹³p/cm²/sec. The resistivity of copper increased linearly with proton fluence at a rate of approximately 3.6×10^-25Ωm/p/cm². Subsequently isochronal annealing was performed. Following the first room temperature anneal, 16% of the induced resistivity was still present. Subsequent irradiations of the same sample indicate that this residual resistivity increases with each irradiation with a tendency to saturate at a higher resistivity. The annealing results and the effects of repeated irradiations will be discussed in detail.