Defects in uc single crystal due to fission damage

Abstract

Single crystals of uranium monocarbide (UC, NaCl-type structure) were irradiated in a nuclear reactor and the effects of fission damage on the electrical resistivity were examined. Increases were observed in the resistivity with increasing fission dose and showed a saturation at about 10¹⁷ fission/cm³. Successive anneals following the irradiations were carried out by both pulse and continuous heating. Three steps were observed in the recovery of the resistivity. Within the steps, isothermal annealings were performed to evaluate migration energies of the recovery processes. By comparison with results of a quenching study for polycristalline UC, it is concluded that vacagcy-type defects are annihilated in the recovery steps at 170 and 525°C.