Development of experimental rigs for temperature-controlled reactor irradiations for fundamental study of radiation effects on fusion materials

The accumulated results of radiation effects on materials have clearly shown that temperature history is very important for the evolution of microstructures induced by irradiation. The Japan Materials Testing Reactor has several preferable features for temperature-controlled irradiation. Two kinds of techniques were applied to control the irradiation temperature. The control of thermal insulation along with heating by the electrical heater, which is the other technique of the temperature control, permits us to control the temperature in the range of 360-1100 K, regardless of whether the reactor is in the operation or out of operation.