Evolution of cavity size distributions in dual-ion irradiated austenitic stainless steel and Fe-Cr-Ni ternary alloys

The first four moments of experimentally measured cavity size distributions in dual-ion irradiated 304SS, Fe-12Ni-15Cr and Fe-30Ni-15Cr alloys have been calculated for a range of fluences, helium injection rates, and irradiation temperatures. The moments are shown to correctly describe the effects of alloy composition, fluence, helium and temperature on the evolution of the cavity size distributions. Experimentally determined moments are compared with those calculated from cavity nucleation and growth theories. The moments reflect the competition between nucleation and growth processes and provide insight into the details of the transient low swelling regime.