Abstract
Abstract
We investigate the effects of ambient temperature and cascade-induced defect evolution on radiation damage accumulation in pure nickel and the nickel-based equiatomic multi-component alloys: NiFe, NiCr, and NiFeCr. We compare predictions of the vacancy concentration in the high-dose limit provided by a novel semi-analytical model informed by individual cascade simulations to results obtained from direct cumulative cascade simulations at 100 K and 800 K. We find that both approaches agree on the decrease of the saturated vacancy content with increasing temperature, despite modeling being carried out in the 'athermal' regime valid on very short time scales. However, the semi-analytical model is unable to capture the differences between the various alloy compositions observed in direct cascade simulations. We attribute these discrepancies to the evolving morphology of the damage, which differs among the alloy compositions. Our results highlight the importance of defect morphology on the development of damage in the high dose limit, and show that accurate predictions of the saturated vacancy concentration require accounting for defect clustering and the production of stable sinks, even in the athermal limit.