温度对碲锌镉光子计数探测器计数性能的影响及机理研究

基于线阵光子计数探测器模块，实现了碲锌镉探测器的光子计数应用。研究了大剂量X射线下碲锌镉探测器的计数性能，发现碲锌镉光子计数探测器根据其典型计数性能可分为两类:C1，C2。分析了这两类典型的光子计数探测器的计数性能与X射线能谱响应特性、前放脉冲信号上升时间以及碲锌镉探测器缺陷水平的内在联系，在此基础上研究了温度对C2类碲锌镉光子计数探测器计数性能的影响规律，升高温度可以抑制探测器的极化失效，提高计数率，且当温度升高至33℃时，探测器计数性能可得到显著改善。最后利用线阵光子计数探测器模块，获得了不同温度下C2类碲锌镉光子计数探测器的多能区成像结果，升高温度可以显著增加其图像衬度，提高成像质量。该研究为通过控制外部条件提高碲锌镉光子计数探测器性能提供了有效手段。

Effect and mechanism of temperature on photon counting performance of CdZnTe detectors

The application of CdZnTe photon counting detectors was achieved based on a linear array photon counting module. Two kinds of typical counting performance (C1, C2) have been observed when CdZnTe photon counting detectors were exposed to high flux X-ray beams. The X-ray pulse height spectrum characteristics, rise time of preamplifier pulse signal and defect level of the two typical CdZnTe detectors were studied and the intrinsic relationship between the above three results and the photon counting performance were demonstrated. Based on these results, the influence of temperature on the photon counting performance of the C2 detectors was studied. Increasing temperature can restrain the failure of detector induced by polarization effect and increase the counting rate, i.e. when the temperature rises to 33℃, the counting performance of the detector was significantly improved. Finally, the multi-energy region imaging results of C2 detectors at different temperatures were obtained using the linear array photon counting module, which showd that raising temperature significantly increase the image contrast and improve the imaging quality. The study provides an effective means to improve the performance of CdZnTe photon counting detectors by controlling external conditions.