为了进行MCP超薄防离子反馈膜的性能评价研究, 并使这种膜层具有良好离子阻挡能力, 利用电子束蒸发方法, 在微通道板(MCP)输入面上制备一种超薄Al2O3防离子反馈膜, 其膜层厚度为2 nm时仍连续致密。通过对Al2O3防离子反馈膜的电子透过特性测试, 给出2 nm及4 nm厚防离子反馈膜对应的死区电压分别约为150 V及200 V; 利用Monte-Carlo法模拟分析了Al2O3防离子反馈膜的离子阻挡特性, 2 nm及4 nm厚Al2O3防离子反馈膜对碳离子等的阻挡率分别高于40%及86%, 另外对有无膜的MCP电特性进行测试, 可以看出镀2 nm及4 nm厚的膜后, MCP电子增益分别降低了51%及81%。

In order to study the properties of the ion barrier film of microchannel plate(MCP), the Al2O3 ion barrier film was successfully fabricated on the input-face of MCP by the e-beam evaporating method.The optimal thickness of the ion barrier film was 2 nm. After measurement, the electron transmittance characteristics through the ion barrier film for unfilmed and filmed MCPs were shown. The relationship between the thickness of the ion barrier film and the dead voltage was given, the dead voltage of Al2O3 ion barrier film with the thickness of 2 nm and 4 nm was 150 V and 200 V, respectively. The stopping function on incident ions was analyzed by Monte-Carlo method, the barrier rate for 2 nm and 4 nm Al2O3 ion film was above 40% and 86%, respectively .Besides, the electrical characteristics of unfilmed MCP were tested, and the results showed that with the Al2O3 ion barrier film of 2 nm and 4 nm, the electron gain of MCP reduced by 51% and 81%,respectively.