碳化硅(SiC)晶体可以用作无源监控器测量反应堆的中子辐照温度,在未来高温强辐射的先进核反应堆中具有重要的应用前景。SiC测温技术自20世纪60年代被首次提出以来,基于SiC结构、热学和电学性质的中子辐照效应,人们建立了宏观尺寸法、质...碳化硅(SiC)晶体可以用作无源监控器测量反应堆的中子辐照温度,在未来高温强辐射的先进核反应堆中具有重要的应用前景。SiC测温技术自20世纪60年代被首次提出以来,基于SiC结构、热学和电学性质的中子辐照效应,人们建立了宏观尺寸法、质量密度法、热导率法和电阻率法等各种SiC测温方法。本文首先综述了这些SiC测温方法的基本原理和工作特点,然后着重介绍了中国原子能科学研究院(China Institute of Atomic Energy,CIAE)SiC测温系统的研究进展,通过中子辐照诱导SiC晶格肿胀的理论计算,分析和验证了该系统测温结果的可靠性,探讨了进一步提高SiC测温效率的实验方法。展开更多
High purity SiC crystal was used as a passive monitor to measure neutron irradiation temperature in the 49-2 research reactor.The SiC monitors were irradiated with fast neutrons at elevated temperatures to 3.2×10...High purity SiC crystal was used as a passive monitor to measure neutron irradiation temperature in the 49-2 research reactor.The SiC monitors were irradiated with fast neutrons at elevated temperatures to 3.2×10^(20)n/cm^(2).The isochronal and isothermal annealing behaviors of the irradiated SiC were investigated by x-ray diffraction and four-point probe techniques.Invisible point defects and defect clusters are found to be the dominating defect types in the neutron-irradiated SiC.The amount of defect recovery in SiC reaches a maximum value after isothermal annealing for 30 min.Based on the annealing temperature dependences of both lattice swelling and material resistivity,the irradiation temperature of the SiC monitors is determined to be~410℃,which is much higher than the thermocouple temperature of 275℃ recorded during neutron irradiation.The possible reasons for the difference are carefully discussed.展开更多
文摘碳化硅(SiC)晶体可以用作无源监控器测量反应堆的中子辐照温度,在未来高温强辐射的先进核反应堆中具有重要的应用前景。SiC测温技术自20世纪60年代被首次提出以来,基于SiC结构、热学和电学性质的中子辐照效应,人们建立了宏观尺寸法、质量密度法、热导率法和电阻率法等各种SiC测温方法。本文首先综述了这些SiC测温方法的基本原理和工作特点,然后着重介绍了中国原子能科学研究院(China Institute of Atomic Energy,CIAE)SiC测温系统的研究进展,通过中子辐照诱导SiC晶格肿胀的理论计算,分析和验证了该系统测温结果的可靠性,探讨了进一步提高SiC测温效率的实验方法。
文摘High purity SiC crystal was used as a passive monitor to measure neutron irradiation temperature in the 49-2 research reactor.The SiC monitors were irradiated with fast neutrons at elevated temperatures to 3.2×10^(20)n/cm^(2).The isochronal and isothermal annealing behaviors of the irradiated SiC were investigated by x-ray diffraction and four-point probe techniques.Invisible point defects and defect clusters are found to be the dominating defect types in the neutron-irradiated SiC.The amount of defect recovery in SiC reaches a maximum value after isothermal annealing for 30 min.Based on the annealing temperature dependences of both lattice swelling and material resistivity,the irradiation temperature of the SiC monitors is determined to be~410℃,which is much higher than the thermocouple temperature of 275℃ recorded during neutron irradiation.The possible reasons for the difference are carefully discussed.
