Characteristics of the high temperature fission chamber CFUE32 in pulse mode

The Thorium Molten Salt Reactor (TMSR) is a class of generation IV nuclear fission reactor. When the reactor is operating, the temperature of the neutron detection environment will reach 550 ℃ or higher. Therefore, the applications of neutron detectors will be extremely limited. Fission chamber is one of the most important types in neutron detectors. Measurements of the high temperature fission chamber (HTFC) will be helpful to the TMSR measurements scheme and the research of neutron detector applications. This study aims to understand the detection performance of the Photonis fission chamber CFUE32 at different temperatures range from 17.1 ℃ to 550 ℃. Xi'an Pulsed Reactor was used as the neutron source. A portable heater provides the high temperature environment. Counting rate-Voltage curves and pulse amplitude spectrums of the detector were measured. An obvious decrease in detection performance was observed in CFUE32 when the temperature is above 450 ℃. (authors)