Production Rates of Electrical Resistivity in Copper and Aluminum Induced by Electron Irradiation

Polycrystalline copper and aluminum were bombarded below 6^∘{}K with monoenergetic electrons with energies in the range 0.15 to 2.1 MeV. The production rates of electrical resistivity were measured and the threshold energies for atom displacement were found to be 19±{}3 eV for copper and 16±{}2 eV for aluminum. The results indicate that the probability function for atom displacement is not a single step for either copper or aluminum. More complex function are considered, and multiple displacements appear to be important for both metals for the energy range studied.