Flux dependence of void nucleation and void growth in 2.8-MeV nickel-ion- irradiated nickel

Swelling in reactor materials can be simulated, at least qualitatively, by irradiation with heavy ions in a small fraction of the time required with neutron irradiation. However, the 103−105 higher production rate of initial damage which makes simulation feasible may also obscure subtle microstructural changes. Thus, the dose rate effects need to be understood. The present investigation obtained a quantitative comparison between the damage parameters in 2.8−MeV nickel−ion−irradiated nickel, where the nickel ion flux was the only variable, being changed by a factor of 100. Preliminary results of studies of some of the samples of this investigation were described at a recent conference.1 The paper presents further analyses of these and other samples and comparison with theories of void nucleation and void growth.