论文标题
5毫米厚的正交cdznte探测器系统的电极设计的优化研究
Optimization study of the electrode design of a 5 mm thick orthogonal-strip CdZnTe detector system
论文作者
论文摘要
电极的几何形状是确定正交探测器性能的最重要因素之一。这项工作的目的是研究具有不同电极宽度的5毫米厚的跨跨CDZNTE检测器的性能。我们的研究包括两个主要部分，模拟和实验。我们利用了四个不同的阳极尺寸，范围为0.1 mm至0.6 mm。将阳极与转向电极插入，尺寸从0.3 mm到0.85 mm。阳极和转向电极条之间的最大间隙尺寸设置为0.3 mm，而最小间隙尺寸为0.125 mm。根据转向电极偏置电压，能量分辨率和电荷共享效果研究了检测器的性能。为了进行模拟，我们开发了一个基于C ++的模拟程序，用于电极内CDZNTE检测器内部的电荷传输和电荷收集。对于光子相互作用，我们使用了GEANT4工具包，用于电场和加权模拟，我们使用了COMSOL软件。结果表明，当将-500 V应用于阴极时，-50 V是我们检测器的最佳转向电极偏置，并且能量分辨率性能随着转向电极宽度的增加而下降。同样，对于较大的转向电极尺寸，电荷共享效果变得更有主导。将实验结果与模拟进行比较。结果达成了很好的一致性，比较验证了我们的仿真模型。虽然，我们的模拟框架需要更好地估计CDZNTE的固有噪声。这些结果表明，需要进行电极宽度和转向电极偏置之间的优化研究，以获得正交分带CDZNTE探测器中的最佳性能。
The geometry of electrodes is one of the most important factors in determining the performance of orthogonal-strip detectors. The aim of this work is to study the performance of a 5 mm thick cross-strip CdZnTe detector with different electrode widths. Our study consists of two main parts, simulations and experiments. We utilized four different anode sizes ranging from 0.1 mm to 0.6 mm. The anodes were interspersed with steering electrodes with varying sizes from 0.3 mm to 0.85 mm. The maximum gap size between the anodes and steering electrode strips was set to 0.3 mm, while the minimum gap size was 0.125 mm. The performance of the detector was investigated in terms of the steering electrode bias voltage, the energy resolution, and the charge sharing effect. For simulations, we developed a C++ based simulation program for charge transport inside the CdZnTe detector and charge collection at the electrodes. For photon interactions we used GEANT4 toolkit and for electric field and weighting potential simulations we used COMSOL software. The results demonstrated that -50 V is the optimal steering electrode bias for our detector when -500 V was applied to the cathodes and that the energy resolution performance drops with increasing steering electrode width. Also, the charge sharing effect becomes more dominant for larger steering electrode sizes. The experimental result are further compared with the simulations. The results are in a good agreement and the comparison validates our simulation model. Although, our simulation framework has need of better estimation for the intrinsic noise of CdZnTe. These results suggest that an optimization study between electrode widths and steering electrode bias is required to obtain the best performance in orthogonal-strip CdZnTe detectors.
