Atom transport efficiency in heavy ion irradiated metals

Multi-layer specimens were used to investigate diffusion near the irradiate d surface in nickel single crystals under heavy ion irradiation at temperat ures around the swelling rate maximum 800-950 K. Analysis of the data yield s information on the effective fraction eta of the displacement rate, with which transporting defects are produced (production rate of freely migratin g defects), and on the radiation-induced sink strength. Upper limits of eta = 7% are calculated for a self-ion irradiation at 950 K. In the investigat ed temperature range defect kinetics is dominated by the high sink strength of about 10(15) m(-2). (C) 1999 Elsevier Science B.V. All rights reserved.