LOW-TEMPERATURE NEUTRON IRRADIATION DAMAGE IN ALUMINUM AND GOLD

Fast-neutron irradiation damage at 1.74 °K and its recovery to 100 °K have been investigated in Al and Au by means of residual electrical resistivity measurements. The effects of impurities, quenched-in vacancies, and dislocations were studied. It was found that the damage rate of Al was unchanged by impurity concentrations of less than 0.5 at. % and quenched-in vacancy concentrations of less than 0.002 at. %. Dislocation concentrations of ~2 × 1010/cm2 in Al and ~1011/cm2 in Au increased their damage rates by 35%and 50% respectively. Small amounts of impurity (~0.02 at. %) in Au increased its damage rate by 15% and suppressed the enhancement caused by deformation. The stage I recovery of Al and Au was only slightly increased by extra dislocations, but was increased considerably by quenched-in vacancies. An impurity concentration of ~0.5 at. % suppressed the stage I recovery of Al, but not that of Au. The results are interpreted in terms of channeling in Al and collision chains in Au.