Neutron irradiation influence on high-power thyristor device under fusion environment

Abstract

Because of their economy and applicability, high-power thyristor devices are widely used in the power supply systems for large fusion devices. When high-dose neutrons produced by deuterium–tritium (D–T) fusion reactions are irradiated on a thyristor device for a long time, the electrical characteristics of the device change, which may eventually cause irreversible damage. In this study, with the thyristor switch of the commutation circuit in the quench protection system (QPS) of a fusion device as the study object, the relationship between the internal physical structure and external electrical parameters of the irradiated thyristor is established. Subsequently, a series of targeted thyristor physical simulations and neutron irradiation experiments are conducted to verify the accuracy of the theoretical analysis. In addition, the effect of irradiated thyristor electrical characteristic changes on the entire QPS is studied by accurate simulation, providing valuable guidelines for the maintenance and renovation of the QPS.