A quenching and annealing study of neutron-irradiated aluminium by positron annihilation

Abstract

Abstract The Doppler broadening of the positron annihilation line has been measured on polycrystal samples of quenched aluminium, neutron-irradiated aluminium, and quenched, neutron-irradiated aluminium, as a function of temperature over the range 130 K to ∼600 K. A peak in the lineshape (S) parameter is observed in both quenched samples, and is attributed to vacancy clustering. This peak is enhanced in the irradiated sample, probably b ecause of the presence of transmutation-produced silicon in this sample. The S parameter for the unquenched, irradiated sample also shows an interesting temperature dependence, some of which is produced by the temperature dependence of positron trapping into voids.