Point defect generation in pulsed impure solids

Smidt et al.(Radiation Induced Voids in Metals, edited by J.W. Corbett and L.C. Ianniello (USAEC 1971)p.613) bombarded thin metal foils with intense laser pulses and then annealed thinned and examined the foils by transmission electron microscopy. Various types of defect were observed. In the present note a mechanism is proposed which assumes that a stress wave is produced by the pulse: the effect on atoms of the metal and neighbouring atoms of impurity (of different mass number) is to accelerate them to different velocities so that they separate and generate defects. (U.K.)