物理学报2024，Vol.73Issue(14)：46-52,7.DOI:10.7498/aps.73.20240302
电子束透射氮化硅薄膜窗产生低密度等离子体
Low-density plasmas generated by electron beams passing through silicon nitride window
摘要
Abstract
In general,more attention is paid to how to improve the characteristic parameters of plasma in plasma applications.However,in some cases,it is necessary to produce plasma with low-electron density,such as in the laboratory simulation of ionospheric plasma in space science.In this study,a low-density plasma is generated by electron beams passing through a silicon nitride transmission window under low pressure condition.The transmission properties of electron beam passing through silicon nitride films are investigated by Monte Carlo simulation,and the plasma feature is studied by a planar Langmuir probe and a digital camera.It is found that the plasma exhibits a conical structure with its apex located at the transmission window.At a constant pressure,the cone angle of conical plasma decreases with the electron energy increasing.This is qualitatively consistent with the Monte Carlo simulation result.The frequency of electron-neutral collisions increases as the working pressure rising,which leads the plasma cone angle to increase.When the beam current is reduced from 10 μA to 0.5 μA at 40 keV,the electron density decreases,in a range between 105 and 106 cm3,while the electron temperature does not change significantly but approaches 1 eV.It can be inferred that the electron density decreases with the distance z from the transmission window in the incident direction of the electron beam.A low-density plasma of less than 105 cm 3 can be obtained further away from the transmission window.关键词
电子束/等离子体产生/等离子体源/电子密度Key words
electron beam/plasma generation/plasma source/electron density引用本文复制引用
颜劭祺,高继昆,陈越,马尧,朱晓东..电子束透射氮化硅薄膜窗产生低密度等离子体[J].物理学报,2024,73(14):46-52,7.基金项目
国家重点研发计划(批准号:2018YFE0301102)资助的课题. Project supported by the National Key Research and Development Program of China(Grant No.2018YFE0301102). （批准号:2018YFE0301102）
