Long-term room temperature stability of TlBr gamma detectors
Long-term room temperature stability of TlBr gamma detectors
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TlBr 伽马探测器的长期室温稳定性
DOI：
10.1117/12.896713
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
K. Shah
中科院分区：
文献类型：
--
作者：
A. Conway;L. Voss;A. J. Nelson;P. Beck;R. Graff;R. Nikolic;S. Payne;H. Kim;L. Cirignano;K. Shah
溴化铊（TlBr）是一种在室温伽马射线探测器应用中备受关注的材料，因为它具有2.7电子伏特的宽禁带以及较高的平均原子序数（铊为81，溴为35）。研究人员已经在662千电子伏特处实现了1.3%的能量分辨率，这证明了该材料体系的潜力。然而，众所周知，使用传统配置时这些探测器会发生极化，从而限制了它们的使用。基于溴化铊的室温高分辨率伽马射线探测器的持续改进需要进一步了解其性能退化机制。虽然高质量的材料是实现优异探测器性能的关键起点，但我们表明，通过氢氟酸和盐酸处理，平面溴化铊伽马能谱仪的室温稳定性可以显著提高。通过将氟（F）或氯（Cl）掺入溴化铊表面，电流不稳定性得以消除，并且探测器的长期电流保持不变。还表明镅 - 241能谱在较长时间内更加稳定；探测器在2000伏/厘米的电压下保持52天，其峰质心位置的退化小于10%。此外，还提出了长期退化机制与接触金属有关的证据。
TlBr is a material of interest for use in room temperature gamma ray detector applications due to is wide bandgap 2.7 eV and high average atomic number (Tl 81, Br 35). Researchers have achieved energy resolutions of 1.3 % at 662 keV, demonstrating the potential of this material system. However, these detectors are known to polarize using conventional configurations, limiting their use. Continued improvement of room temperature, high-resolution gamma ray detectors based on TlBr requires further understanding of the degradation mechanisms. While high quality material is a critical starting point for excellent detector performance, we show that the room temperature stability of planar TlBr gamma spectrometers can be significantly enhanced by treatment with both hydrofluoric and hydrochloric acid. By incorporating F or Cl into the surface of TlBr, current instabilities are eliminated and the longer term current of the detectors remains unchanged. 241Am spectra are also shown to be more stable for extended periods; detectors have been held at 2000 V/cm for 52 days with less than 10% degradation in peak centroid position. In addition, evidence for the long term degradation mechanism being related to the contact metal is presented.