金阴极微通道板探测器X射线段的能谱响应

Energy dependent sensitivity of Au-coated-microchannel plate detector in X-ray range

利用表面镀金阴极膜的微通道板（MCP）构成一种金阴极MCP光电探测器,根据MCP的电阻电容特性提出了一种特殊的能谱响应测量方法。在北京同步辐射3B3中能束线上对该探测器在2.1~6.0keV能段的谱响应进行了实验标定。以美国NIST绝对定标的美国IRD公司生产的AXUV-100硅光二极管为次级标准探测器,标定金膜厚度分别为25和100 nm的金阴极MCP探测器的能谱响应。经分析发现,阴极材料和MCP材料的元素吸收边是造成量子效率曲线出现突变点的原因。对比两种MCP的能谱响应标定结果,金膜厚度为100 nm探测器的能谱响应高于金膜厚度为25 nm的探测器。

A kind of photodetector was developed by microchannel plate（MCP） evaporated with Au photocathode.According to the resistive and capacitive characteristics of MCP,a method for measuring the energy dependent sensitivity was established.The response of the detector for incident energy from 2.1 to 6.0 keV was calibrated on the 3B3 medium energy X-ray beamline.An AXUV-100 silicon diode,which was produced by IRD Company and absolutely calibrated by NIST,was used as the secondary standard detector to calibrate two Au-coated-MCP detectors with 25 and 100 nm thick Au films,respectively.The experimental result,shows that,the elements＇ absorption line and the thickness of Au film are very important to the quantum efficiency,and the sensitivity of the detector with 100 nm thick Au film is higher.