He/Ar混合气体空心阴极放电特性的模拟研究  

Discharge Characteristics in Hollow Cathode Filled with Helium/Argon Mixture:A Simulation Study

作　　者：张雅 渠宇霄 赵凯悦 何寿杰[1] 赵雪娜[1] 李庆[1] Zhang Ya;Qu Yuxiao;Zhao Kaiyue;He Shoujie;Zhao Xuena;Li Qing(College of Physics Science and Technology,Hebei University,Baoding 071002,China)

机构地区：[1]河北大学物理科学与技术学院,保定071002

出　　处：《真空科学与技术学报》2019年第3期237-244,共8页Chinese Journal of Vacuum Science and Technology

基　　金：国家自然科学基金项目(51777051);河北省自然科学基金项目(A2016201025);河北大学大学生创新创业训练项目(2018 082)

摘　　要：为了进一步揭示He/Ar混合气体中空心阴极放电机理,利用流体模型模拟研究了He/Ar混合气体环境下空心阴极放电的放电特性,模拟得到了电势、电子密度、He^+和Ar^+密度、电场强度的分布特性。本文特别对He/Ar混合气体环境下中He和Ar对新电子的产生机理,即不同类型电离速率以及电压对电离机制的影响进行了研究。结果表明:整个放电区域分为阴极位降区和负辉区。阴极位降区内存在很强的径向电场,较高的离子和电子密度差,高电子平均能量。负辉区电场强度和平均电子能量很低,电子和离子密度峰值位于负辉区。氩气的加入大大促进了放电的进行。虽然Ar原子所占比重只有5%,但是氩气在放电过程中起着和氦气同等重要的作用。Ar的离子和亚稳态原子密度均高于He的离子和亚稳态原子密度,同时,Ar^+对二次电子发射影响要高于He^+。随着电压的升高,电子和离子密度升高,阴极位降区径向电场强度和平均电子能量增加,负辉区内径向电场和电子平均能量降低,电离速率增高。氩气所参与的电离速率比重略微增加,分步电离所占总的电离速率比重出现明显增加。The discharge in He/Ar hollow cathode was mathematically modeled,theoretically analyzed in fluid dynamics and numerically simulated to deepen the understanding of discharge mechanisms.The "cathode potential rapid dropping" and "negative glow" zones were found to coexist,where the plasma displays significant different properties,including the density and average energy of electron and ion.The simulated results show that the 5% Ar and voltage have a major impact.To be specific,the densities of ion and metastable atom of Ar are higher than those of He,possibly because of a lower ionization energy and a stronger impact of Ar atom on secondary electron emission.As the voltage increases,the ionization rate,ion density and electron density increased,simply due to the increases of electric field strength and electron energy.

关 键 词：空心阴极放电 He/Ar混合气体 流体模型 电离速率 粒子密度 

分 类 号：O53[理学—等离子体物理]