微通道板离子壁垒膜粒子阻透特性的蒙特卡罗模拟(英文)

Monte-Carlo Simulations on The Stopping and Transmittance Characteristics of Particles in The Ion Barrier Film of Microchannel Plate

在三代微光像管中,微通道板(MCP)输入面上覆盖一层超薄离子壁垒膜(IBF),目的是保护光电阴极,延长像管使用寿命。为了深入研究离子壁垒膜的特性,本文对Al2O3和SiO2两种离子壁垒膜的粒子阻透能力进行了蒙特卡罗模拟,结果表明:5 nm厚Al2O3和SiO2离子壁垒膜的死电压分别为230～240 V和220～230 V之间;输入能量0.24 keV时背散射电子数最高达19%左右;输入能量0.8 keV时,Al2O3膜电子透过率为87.16%,SiO2膜为88.12%,电子透过的极限膜厚前者为15 nm,后者为16 nm;对于输入能量0.26 keV的C+、N+、O+离子,Al2O3膜的离子阻当率为95%～99%;Al2O3离子壁垒膜在厚度5 nm时具有较好的电子透过率和较高的离子阻挡率。

In the third-generation low-level-light image tube,a super thinner ion barrier film（IBF） was covered on the input surface of microchannel plate（MCP） to protect the photocathode and prolong the operation life of the image tube.In order to further investigate the properties of IBF,a Monte-Carlo simulation on the stopping and transmission characteristics of particles in Al2O3 and SiO2 IBFs were conducted.It was found that the dead-voltage was 230～240 V and 220～230 V for Al2O3 and SiO2 IBF with the thickness of 5 nm,respectively.The number of the back-scattered electron was as high as 19% for the incident electrons with energy of 0.24 keV.For the incident energy of 0.8 keV,the electron transmittance was 87.16% and 88.12%,and the limited thickness of the IBF was 15 nm and 16nm for Al2O3 and SiO2 film,respectively.For C＋,N＋ and O＋ ions with energy of 0.26 keV,the ion stopping power was 95%～99% for Al2O3 IBF.The Al2O3 IBF showed satisfied electron transmittance and ion stopping power when the thickness of IBF was 5 nm.