In order to investigate possible interactions between freely migrating defects and the remnants of energetic displacement cascades, radiation-induced segregation in the present alloy was measured by means of Rutherford back-scattering spectrometry during separate and simultaneous bombardment with 1.5MeV He ions and 800keV Cu ions at 400C. A marked radiation-induced segregation, which was observed only during He bombardment, was greatly reduced under simultaneous Cu bombardment at approximately the same dpa rate. It was found that increasing the Cu flux by a factor of 5 almost completely suppressed the radiation-induced segregation that was produced by the He bombardment. The suppression of radiation-induced segregation at 400C vanished quickly when Cu bombardment ceased. The results demonstrated that a transient population of interstitial and/or vacancy clusters, caused by Cu bombardment, greatly reduced the survival rate of the freely migrating defects that were produced by the He bombardment.

A.Iwase, L.E.Rehn, P.M.Baldo, L.Funk: Applied Physics Letters, 1995, 67[2], 229-31