大面积微通道板(MCP)电子清刷测试系统设计

Design of large area MCP electron rinse and test system

电子清刷是提升MCP性能的有效手段,鉴于目前国内的清刷测试系统只适用于直径30mm以下的MCP,设计了一套4工位大面积MCP(500mm×100mm)的清刷测试系统。该系统4个工位均可实现对大面积MCP的电子清刷,且其中一个工位兼具测试功能,可以测试清刷前后MCP的参数变化,清刷测试工位可实现相互转换。通过均匀紫外光照射金阴极产生均匀电子再经标准MCP(Φ105mm)倍增后得到用于清刷的可调均匀电子束。多次抽真空、检漏、及对该系统的烘烤处理使该系统达到真空度5×10^(-4) Pa的时间小于45min,且极限真空度优于5×10^(-5) Pa,完全满足了清刷测试的指标要求。针对负载对该真空系统抽真空难度带来的影响,定义了负载影响因子K,并在实验过程中对K值作了量化计算(K值在0.35~1.57范围内),揭示了K值与该系统抽真空难度存在的正比例关系。

Electron rinse process is an effective way to improve the performance of microchannel plate(MCP).In view of the domestic electron rinse and test system only applied to the MCP with diameter of 30 mm and above at presents,an electron rinse and test system with 4stations for large-area MCP(500mm×100mm)was designed.In this system,the electron rinsing of MCP could be conducted on each station at the same time,and the parameters could be tested at one of the stations in the process of the electron rinsing at different stages.4stations in the vacuum system could be converted to each other quickly.By emitting a uniform ultraviolet light on the gold cathode,the uniform electrons were generated,then an adjustable uniform electron beam could be obtained after uniform electrons being increased by standard MCP(Φ105mm).Through vacuum,leakage detection and baking processes by several times,the time reaching the vacuum degree of 5×10^(-4) Pa was obtaind within 45 min,and the limit vacuum degree was better 5×10^(-4) Pa,which could meet the index requirement of rinsing and testing.For measuring the effect on the vacuum pumping difficulty of the vacuum system brought by the load,the factor K was defined in the experiment progress.Calculations show that the value of K was inthe range of 0.35~1.57,and the positive proportion of factor Kand pumping difficulty of the system was revealed.