Comparative Study on Responses of Three Candidate Materials for ADS Beam/Target Windows to Proton Irradiation: T91, SIMP and Ti-6Al-4V

Accelerator-Driven System (ADS) represent an advanced nuclear energy system designed for the purpose of transmuting and eliminating nuclear waste. The irradiation tolerance of a material stands out as a critical factor in determining its availability for ADS beam/target windows. This study delves into the response of three promising candidates (T91, SIMP, and Ti-6Al-4V) for ADS beam/target windows to proton irradiation, as investigated by a 1.4MeV H2+ irradiation experiment to dose of 1.5 peak dpa at 460 °C. Their cavity swelling and hardening behavior were estimated using Transmission Electron Microscope (TEM) and Nanoindentation, respectively. It was demonstrated that SIMP steel shows lower cavity swelling but slightly higher irradiation hardening compared to T91. Notably, no cavity swelling is observed in Ti-6Al-4V, but it experiences a higher level of irradiation hardening. The nucleation and evolution mechanisms of irradiation-induced defects (including cavities, dislocation loops, and precipitates) and their contributions to the proton irradiation response are discussed. Furthermore, a summary of the advantages and disadvantages of the three materials as candidates for proton beam/target windows is provided.