微通道板式WSZ位敏阳极探测器的图像拖尾处理

Image tailing processing of WSZ position sensitive anode detector based on MCP

分析了极紫外成像仪图像拖尾的原因,提出了消除该现象的方法。分析了坐标计算公式中各个分量变化对图像的影响,结果显示:信号叠加和微通道板(MCP)反馈是系统对坐标分量影响最大的两种因素。通过对图像数据的分析,排除了信号叠加的两种情况即峰堆积和尾堆积产生拖尾的可能性。对拖尾最严重处电荷变化量的计算表明,MCP反馈是产生拖尾的主要原因,而MCP所加高压的幅度是产生反馈的重要因素之一。最后,用在2 950 V和2 800 V高压下采集的图像验证了拖尾是由MCP反馈引发的,并通过实验给出了解决方案:通过烘烤减少MCP通道内的气体残留并定期对MCP进行电子束清刷来降低反馈发生的几率,减小拖尾的影响。

The image tailing generated by an Extreme Ultraviolet imager was analyzed and how to re- move the image tailing phenomena was proposed. The effects of each component change of coordinate calculation formula on the image were analyzed, and it shows that the superposed signal and Micro Channel Plates （MCP） feedbaek are the most influential factors of coordinate components in the sys- tem. After image data analysis, both cases of superposition of signal, peak accumulation and tail accu- mulation, were excluded. The calculation on change of quantity of charge at the most serious tailing place shows that the MCP feedback may be the reason of image tailing. However, the amplitude of high voltage applying on the MCP is one of the important factors affecting feedback occurs. The ima- ges sampled at 2 950 V and 2 800 V were validated and it indicates that the tailing is sparked by theMCP feedback. Moreover, solutions were given, that are to reduce rudimental gas in the MCP by baking and to clean the MCP by electron beams regularly.