Research On SiC Neutron Detector Technology For High Temperature And Strong Radiation Field

Space reactor power system is considered as an ideal energy source in space,which is significant for the development of space technology.To ensure that the space reactor can work stably for a long time in space,it's important to measure the neutron fluences to monitor the working condition of space reactor.But the neutron detectors need to withstand harsh environment such as high temperature or radiation on the space reactor,which is challenging for neutron detector.Commonly used neutron detectors have limitations in aforesaid conditions at present.4H-SiC inherits the advantages of traditional semiconductors,and it is also resistant to high temperature and radiation,which indicates that neutron detectors using 4H-SiC may conquer the challenge to measure neutron fluences on the space reactor.To verify this assumption,the combined effects of high temperature and n/y irradiation on 4H-SiC detector have been investigated.In order to study the performance of 4H-SiC detector in high temperature,the testing method of 4H-SiC detector in high temperature has been established,and the electrical properties testing and charged particle detection of 4H-SiC detector in high temperature were completed.Charged particles detection is for simulation of secondary charged particles caused by thermal neutron and 6LiF converter.The leakage current of 4H-SiC detector was only 98.7nA at 200 C and-70V;the energy linearity coefficient was better than 0.9997 in detection of 226Ra source in the temperature range from room temperature to 200?;the energy resolution of 4H-SiC was 2.36%in detection of alpha particles of 5.486MeV at 200?.To study effect of n/y irradiation on 4H-SiC detector,4H-SiC detector was irradiated by 60? gamma rays and in CFBR-? reactor,and then the performance of 4H-SiC detector was tested at room temperature.The forward current of the 4H-SiC detector increased and the reverse current decreased after gamma irradiation;after 4H-SiC detector was irradiated by 60Co gamma-rays up to 1MGy,the charge collection efficiency of 4H-SiC detector in detecting alpha particles with energy of 5.486MeV was 93.55%,and the energy resolution was 2.32%.After 4H-SiC detector received high-dose neutron irradiation(1x1013n/cm2?1x1014n/cm2),the forward current and reverse current of the 4H-SiC detector were sharply reduced;after 4H-SiC detector was irradiated by neutron up to 1x1014n/cm2,the forward current can't turned on,and the charge collection efficiency is reduced to 74.11%while the energy resolution is 2.32%in detection alpha particle with energy of 5.486MeV.On the basis of aforesaid studies,the combined effect of high temperature and n/y irradiation on 4H-SiC detector was investigated.After 4H-SiC detector was irradiated by 60Co gamma-rays up to 1MGy,the energy resolution of 4H-SiC was 2.32%in detection of alpha particles of 5.486MeV at 200?.After being irradiated by neutron up to 1x1013n/cm2,the energy resolution of 4H-SiC was 2.30%in detection of alpha particles of 5.486MeV at 200?.This paper proves that the 4H-SiC detector showed well resistance to high temperature and radiation.After being irradiated by 60Co gamma-rays up to 1MGy or by neutron up to 1lx1013n/cm2 neutron,the 4H-SiC detector still work well in detection of charged particle in high temperature up to 200?.4H-SiC detector has the feasibility of neutron detection in the above dose range and temperature range,and can be applied to detect neutron in the harsh environment with high temperature and radiation such as space reactor.