Low dose damage rate of Al foils irradiated with α particles

Al foils of different purity were irradiated with α particles of a 210Po source from 80K to 250K up to a resistivity increase of about 1.5nωcm. The 80 K damage rates of the unalloyed samples show a smaller decrease with increasing dose than expected from experiments with electrons. This can be explained quantitatively by extending the unsaturatable trap model to the complex structure of α damage (depleted zones). The extrapolation to vanishing irradiation dose gives different 80 K damage rates for the various sample materials. As a function of temperature the initial damage rates show a decrease with increasing temperature similar to measurements of resistivity recovery in the same temperature interval using similar materials. (author)