Measurements were made of positron annihilation lifetimes in specimens which had been deformed by up to 75%. It was found that the lifetime exhibited saturation at deformations which were larger than those that corresponded to a 15% reduction in thickness. The lifetime varied from 231ps in annealed material, to 249ps in dislocation-saturated samples.

M.Abdelrahman, E.Badawi: Japanese Journal of Applied Physics, 1996, 35[1-9A], 4728-9