3-D position sensitive CdZnTe spectrometer performance using third generation VAS/TAT readout electronics
3-D position sensitive CdZnTe spectrometer performance using third generation VAS/TAT readout electronics
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DOI：
10.1109/tns.2005.856821
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发表时间：
2005-12
影响因子：
1.8
通讯作者：
Feng Zhang;Zhong He;G. F. Knoll;D. Wehe;J. Berry
中科院分区：
文献类型：
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作者：
Feng Zhang;Zhong He;G. F. Knoll;D. Wehe;J. Berry
采用新的VAS 3.1/TAT 3 ASIC读出器的三维（3-D）位置灵敏CdZnTe（CZT）γ射线谱仪的开发和测试。每个光谱仪都是一个1.5 /spl times/ 1.5 /spl times/ 1 cm/sup 3/ CdZnTe晶体，11 /spl times/ 11像素化阳极使用带有电镀通孔的中间陶瓷基板引线键合到读出电子器件。来自阳极像素和阴极的信号都使用这些ASIC读出。像素位置提供相互作用的横向坐标，而阴极与阳极信号比和电子漂移时间用于获得相互作用深度。利用3-D位置信息，加权电位、电子俘获和材料不均匀性的变化可以解释为位置分辨率的尺度，/spl sim/1.27/spl times/ 1.27/spl times/ 0.2 mm。新的VAS 3.1/TAT 3 ASIC具有更小的增益和基线漂移、更低的串扰噪声、更均匀的阈值，更好的线性度和更好的时序分辨率比我们以前的VAS 2/TAT 2系统。例如，首次观测到了来自/sup 137/Cs源的32 keV K X射线。两个3-D的位置敏感CZT光谱仪进行了测试，都达到了优于1%的FWHM能量分辨率（在662千电子伏，室温操作，与未准直源）的单像素事件。给出了这两个三维位置灵敏CZT光谱仪系统的实验结果并进行了讨论。
Three-dimensional (3-D) position-sensitive CdZnTe (CZT) gamma-ray spectrometers employing new VAS3.1/TAT3 ASIC readouts were developed and tested. Each spectrometer is a 1.5 /spl times/ 1.5 /spl times/ 1 cm/sup 3/ CdZnTe crystal with 11 /spl times/ 11 pixellated anodes wire-bonded to the readout electronics using an intermediate ceramic substrate with plated-through-via. The signals from the anode pixels and the cathode were all read out using these ASICs. The pixel position provides the lateral coordinates of interactions, while the cathode to anode signal ratio and electron drift times are used to obtain interaction depths. Using the 3-D position information, the variation in weighting potential, electron trapping and material nonuniformity can be accounted for to the scale of the position resolution, /spl sim/1.27 /spl times/ 1.27 /spl times/ 0.2 mm. The new VAS3.1/TAT3 ASIC has less gain and baseline drift, lower cross-talk noise, more uniform thresholds, better linearity and better timing resolution than our previous VAS2/TAT2 system. For example, the 32 keV K X-ray from a /sup 137/Cs source was observed for the first time. Two 3-D position sensitive CZT spectrometers were tested and both achieved better than 1% FWHM energy resolution (at 662 keV, room temperature operation, with an uncollimated source) for single-pixel events. The experimental results for these two 3-D position sensitive CZT spectrometer systems are presented and discussed.