It was recalled that, during fast heavy-ion irradiation, defect creation and annealing did not result only from nuclear collisions but also from inelastic collisions of the incident ions with electrons of the target atoms. Here, calculations were made of the spatial distributions and yields of the defects which were introduced by nuclear collisions in metals under GeV ion irradiation. Defect annealing was then simulated by using the thermal spike model. In the case of Fe, the calculations were consistent with known experimental conditions for incident ions. Upon using the same value of the electron-phonon coupling constant as that determined for damage creation, the calculated results suggested that the threshold value for defect annealing was about 15keV/nm. This value agreed with experimental data to within experimental error. Upon taking account of a normalization factor, the calculated damage efficiency was found to agree with experimentally measured values.

Z.G.Wang, C.Dufour, E.Paumier, M.Toulemonde: Nuclear Instruments and Methods in Physics Research B, 1996, 115[1-4], 577-80