极紫外波段微通道板光子计数探测器

Microchannel plate photon counting detector in UV range

研究了一种极紫外波段微通道板(MCP)光子计数探测器,用于探测地球等离子体层中极微弱的30.4 nm辐射。通过改变电压、温度等参数对比了该微通道板光子计数探测器的暗噪声和分辨率的变化。结果表明:微通道板探测器的暗噪声主要来源于残余气体离子反馈和热噪声,因此要降低探测器暗噪声,应对微通道进行彻底的预处理除气,并尽量避免探测器在高温状态下工作,常温下经过预处理的微通道板光子探测系统的暗计数率仅为0.34 count/(s.cm2)。系统的分辨率主要受电压和计数率的影响,受温度影响不明显。由于不同的微通道板有不同的耐压范围,过小或过大的电压或计数率都会造成系统分辨率的降低。

A Microchannel Plate（MCP） photon detector was developed to detect the 30.4 nm radiation in a plasma layer of the earth.By changing voltages,temperatures and other parameters,the variations of the dark noise and resolution for the MCP detector were compared.The results indicate that the dark noise of the detector comes from the ion feedback of residual gas and the thermal noises mainly.Therefore,to reduce the dark noise,the microchannel should be preprocessed by removing residual gases and the detector could not work at a high temperature state.After preprocessing at the room temperature,the dark noise counting rate of the detector has reduced to 0.34 count/s·cm2.Furthermore,the temperature has a little effect on the resolution of the detector,and the resolution dependents on the variances of voltage or counting rate obviously.With different resist pressure abilities for different MCPs,it demonstrates that the proper voltage or counting rate can provide a better resolution.