Comparison Between Silicon Carbide and Diamond for Thermal Neutron Detection at Room Temperature
Comparison Between Silicon Carbide and Diamond for Thermal Neutron Detection at Room Temperature
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碳化硅与金刚石室温热中子探测比较
DOI：
10.1109/tns.2020.2981059
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发表时间：
2020
影响因子：
1.8
通讯作者：
W. Vervisch
中科院分区：
文献类型：
--
作者：
O. Obraztsova;L. Ottaviani;B. Geslot;G. de Izarra;O. Palais;A. Lyoussi;W. Vervisch
核反应堆中子辐射探测器是获取实际中子注量率信息的重要设备。这种探测器必须能够在高中子通量水平（>109 cm−2 s−1）下工作，并区分核反应堆的中子-伽马混合环境中的中子和伽马响应。碳化硅和金刚石是最有吸引力的中子探测半导体材料，这要归功于它们出色的性能，如高位移阈值能量和宽带隙能量，这使它们能够在高辐射水平和高温下工作。本文的目的是比较这两种半导体在相同辐照条件下探测热中子的能力。为此，在CEA Cadarache的MINERVE研究堆上进行了探测器的中子辐照试验。4 H-碳化硅（SiC）p+n二极管在0 V偏置电压下比在−200 V下表现出更好的中子-伽马辨别力，这是通过其对−200 V下的伽马光子的灵敏度增加来解释的，这是由比0 V下更宽的电荷收集区域引起的。优选使用没有外部电场的4 H-SiCp +n二极管用于中子-γ混合环境例如核反应堆环境中的应用。结果表明，单晶化学气相沉积（sCVD）金刚石基探测器具有更好的中子-伽马鉴别，这要归功于使用6Li代替10 B作为中子转换器。然而，对探测器辐射稳定性的研究表明，sCVD金刚石基探测器在高中子通量（~109 cm $^{-2}\，\，\cdot \，\，\text{s}^{-1}$）下工作时会受到“极化效应”的影响。
Neutron radiation detector for nuclear reactor applications plays an important role in getting information about the actual neutron flux. Such a detector must be able to operate at high neutron flux levels (>109 cm−2 s−1) and discriminate the neutron and gamma responses in the nuclear reactor’s mixed neutron–gamma environment. Silicon carbide and diamond are the most attractive semiconductor materials for neutron detection, thanks to their outstanding properties, such as high displacement threshold energy and wide bandgap energy, which allow them to operate in high radiation levels and high temperature. The aim of this article is to compare the ability to detect thermal neutrons of these two semiconductors at the same irradiation conditions. For this purpose, the neutron irradiation tests of detectors were implemented at MINERVE research reactor at CEA Cadarache. The 4H-silicon carbide (SiC) p+n diode has demonstrated better neutron–gamma discrimination at 0-V bias voltage than at −200 V which is explained by its increased sensitivity to gamma photons at −200 V caused by a wider charge collection region than at 0 V. Therefore, it is preferable to use the 4H-SiC p+n diode without an external electric field for applications in the mixed neutron–gamma environment such as nuclear reactor environment. The results show that the single-crystal chemical vapor-deposited (sCVD) diamond-based detector has better neutron to gamma discrimination, thanks to the use of 6Li as a neutron converter instead of 10B. However, the study of the radiation stability of detectors showed that the sCVD diamond-based detector suffers from the “polarization effect” when it operates at a high neutron flux (~109 cm $^{-2}\,\,\cdot \,\,\text{s}^{-1}$ ).