感应读出方式紫外光子计数成像技术的研究

搭建了感应读出方式紫外光子计数成像系统,详细介绍了该系统的组成、工作原理和分辨率性能测试.紫外光经过减光和滤光后入射微通道板,产生的光电子在微通道板内倍增后形成电子云,由呈高阻特性的半导体Ge薄膜收集后,通过电荷耦合感应到Ge膜衬底背面的位敏阳极.阳极输出的信号经过电荷灵敏前置放大器、整形放大器后由计算机进行数据采集和处理,最后得到不同位置的光子计数图像.通过分辨率板,测得了该系统分辨率为150 μm,并通过对比试验和分布式RC网络理论模型分析了Ge膜电阻及其衬底厚度对系统性能的影响.该系统在生物超微 关键词： 光子计数成像 电荷感应 Ge膜 位敏阳极

Study of ultraviolet photon counting imaging technology based on induction readout

An ultraviolet photon counting imaging system based on charge induction readout was built and its structure, working principle and spatial resolution are reported. The single photon stream can be obtained via atmospheric dispersion, some weakeners, and narrow-band optical filters. A photo-electron produced in microchannel plate is multiplied, forming a charge cloud, which is collected on the Ge film and then detected through capacitive coupling by a PSA located a few millimeters behind the Ge film. The signal data from the anode is acquired and processed with software after being transformed, filtered and shaped by a charge-sensitive preamplifier and a main amplifier in sequence. Finally, a 30-minute counting image is obtained. The resolution of this system can reach 150 micrometers as tested with the resolution board, and the influence of Ge film resistivity and its substrate thickness on the performance of this system is also analyzed. The system is beneficial in good imaging properties and time resolution to bioluminescence, astronomy and nuclear radiant detection.