Hydrogen trapping in fusion materials due to ion irradiation: Implications for neutron irradiation☆

Abstract A recently developed trap activation model for hydrogen trapping in fusion materials due to ion irradiation has been used to estimate the effects of neutron irradiation on hydrogen trapping. In making these estimates it is assumed that the trap activation cross-section and the hydrogen displacement cross-section are related to the deposited damage energy in the same way for ion irradiation and neutron irradiation. The results suggest that a significant quantity of tritium may be trapped in the damage produced by the neutrons in the structural stainless steel surrounding the plasma chamber of a typical tokamak. Experimental measurement of a key parameter in the model is required, however, prior to making a final evaluation of the severity of this important effect.