Characterization of silicon carbide and diamond detectors for neutron applications
Characterization of silicon carbide and diamond detectors for neutron applications
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DOI：
10.1088/1361-6501/aa7f8b
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发表时间：
2017-10-01
影响因子：
2.4
通讯作者：
Thomas, D.
中科院分区：
文献类型：
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作者：
Hodgson, M.;Lohstroh, A.;Thomas, D.
碳化硅和金刚石中碳原子的存在使这些材料成为直接快中子探测器的理想候选者。此外，低原子序数、强共价键、高位移能、宽带隙和低本征载流子浓度使得这些半导体检测器潜在地适用于需要坚固的、高温的、低伽马灵敏度检测器的应用，例如主动询问，电子个人中子剂量计和恶劣环境探测器的探测能力进行了彻底的直接性能比较，绝缘碳化硅（SiC-SI）、单晶金刚石（D-SC）、多晶金刚石（D-PC）和自偏置外延碳化硅（SiC-EP）探测器进行了测试，并与商用硅PIN（Si-PIN）二极管进行了基准测试，测试范围为α（Am-241），β（Sr/Y-90），游离光子（65 keV至1332 keV）和中子辐射场（包括1.2 MeV至16.5 MeV的单能中子，以及来自AmBe和Cf-252源的中子）。所有探测器都显示出能够通过使用简单的能量阈值直接探测和区分不同的辐射类型和能量判别法SiC器件表现出最佳的中子能量分辨比（E-max（n = 5 MeV）/E-max（n = 1 MeV）约为5），而在D-PC探测器中观察到上级的中子/光子交叉灵敏度比（Emax（AmBe）/Emax（Co-60）约为16）。进一步的工作还表明，交叉灵敏度比可以通过使用一个简单的质子反冲转换层来提高。在D-SC，D-PC和SiC-SI探测器中也观察到稳定性问题，而在照射下，即能量峰位置和/或计数率随时间的变化（通常被称为极化效应）。此外，D-SC、自偏置SiC-EP和半绝缘SiC探测器显示出在-60摄氏度至+100摄氏度的温度范围内工作。
The presence of carbon atoms in silicon carbide and diamond makes these materials ideal candidates for direct fast neutron detectors. Furthermore the low atomic number, strong covalent bonds, high displacement energies, wide bandgap and low intrinsic carrier concentrations make these semiconductor detectors potentially suitable for applications where rugged, high-temperature, low-gamma-sensitivity detectors are required, such as active interrogation, electronic personal neutron dosimetry and harsh environment detectors.A thorough direct performance comparison of the detection capabilities of semi-insulating silicon carbide (SiC-SI), single crystal diamond (D-SC), polycrystalline diamond (D-PC) and a self-biased epitaxial silicon carbide (SiC-EP) detector has been conducted and benchmarked against a commercial silicon PIN (Si-PIN) diode, in a wide range of alpha (Am-241), beta (Sr/Y-90), ionizing photon (65 keV to 1332 keV) and neutron radiation fields (including 1.2 MeV to 16.5 MeV mono-energetic neutrons, as well as neutrons from AmBe and Cf-252 sources).All detectors were shown to be able to directly detect and distinguish both the different radiation types and energies by using a simple energy threshold discrimination method. The SiC devices demonstrated the best neutron energy discrimination ratio (E-max(n = 5 MeV)/E-max(n = 1 MeV) approximate to 5), whereas a superior neutron/photon cross-sensitivity ratio was observed in the D-PC detector (Emax(AmBe)/Emax(Co-60) approximate to 16). Further work also demonstrated that the cross-sensitivity ratios can be improved through use of a simple proton-recoil conversion layer.Stability issues were also observed in the D-SC, D-PC and SiC-SI detectors while under irradiation, namely a change of energy peak position and/or count rate with time (often referred to as the polarization effect). This phenomenon within the detectors was non-debilitating over the time period tested (>5 h) and, as such, stable operation was possible.Furthermore, the D-SC, self-biased SiC-EP and semi-insulating SiC detectors were shown to operate over the temperature range -60 degrees C to + 100 degrees C.