Energy dependence of defect production in displacement cascades in silver

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 ξ̄=1 to ξ̄0.6) 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 ξ=0.3 and an effective transition from ξ=1 to ξ=0.3 centered near recoil energies between 1 and 3 keV.