Progress in spallation materials research

Kikuchi, Kenji; Saito, Shigeru   ; Hamaguchi, Dai; Endo, Shinya; Usami, Koji

Spallation materials research was started in the mid of 1990s in order to have design data for constructing MW grade spallation neutron source facilities. Irradiation materials experiments were conducted by using the existing high-energy accelerator facility at PSI, under the worldwide cooperation. As a result spallation material showed less ductility and larger DBTT shift than neutron irradiation materials. Spallation materials are characterized by the higher concentration of residual He gas in the materials. Bubbles are also observed in the irradiated samples. It is essential to have an accurate evaluation of He gas production rate both numerically and experimentally.