Energy Dependence of Defect Production in Displacement Cascades in Silver

Abstract

Proton damage rates in Ag measured below 10 K show good agreement with calculated defect-production cross sections for low-energy recoils. A substantial decrease in damage efficiency (from $\overline{\ensuremath{\xi}}=1$ to $\overline{\ensuremath{\xi}}\ensuremath{\approx}0.6$) occurs as the energy and/or mass of the incident particle increases and displacement cascades are produced. Preliminary results are consistent with cascade efficiencies near $\ensuremath{\xi}=0.3$ and an effective transition from $\ensuremath{\xi}=1$ to $\ensuremath{\xi}=0.3$ centered near recoil energies between 1 and 3 keV.