Isothermal Annealing Effects in Irradiated Copper

Abstract

Copper wires were bombarded with 12-Mev deuterons at low temperatures. The wires were then allowed to anneal isothermally at successive temperatures from -185°C to +167°C. Recovery of the electrical resistivity increase, produced by the bombardment, was observed at all temperatures. The annealing curves obtained for temperatures between -185°C and -60°C were of such a character that only a number of processes with different activation energies could account for them. One-half of the resistivity increase recovered in this range. The activation energies obtained were observed to be proportional to the absolute temperature. A value of 0.44 ev was found near -100°C. Above -60°C the annealing behaved as though it were a single process with a unique activation energy. This process accounted for 25 percent of the increased resistivity and had an energy of 0.68 ev. At room temperature 25 percent of the increase remained, and further anneals to temperatures as high as 167°C produced only an additional 4 percent recovery.