摘要
利用流体-亚稳态原子模型对柱型空心阴极放电中电场反转和电势垒进行了研究。模拟得到了稳态放电时电势、电子密度、离子密度、电场和粒子流密度等的分布特性。220 V阳极电压和133 Pa氩气下,电子和离子密度峰值位于放电单元中心处,为2.4×1010cm-3;在阴极位降区,离子密度远高于电子密度。负辉区电势高于阳极电势,放电的轴向存在电场反转现象,放电单元的中心处形成一电势垒。电子扩散流密度和电子流密度之比对电场反转的形成有重要影响。文章同时研究了阳极电压对电场反转特性的影响。结果表明,电压升高时,电子扩散流密度升高,电场反转和电势垒现象增强。模拟结果同时表明空心阴极放电模式下有利于电场反转的形成。该研究对于分析空心阴极放电中电场反转的成因有重要的参考价值。
The electric field-reversal in cylindrical hollow cathode discharge was mathematically described with fluid model and transport model of metastable Ar-atom,theoretically analyzed and numerically simulated. The potential distribution,electron and ion densities,an d particle flow rates at 220 V and 133 Pa of argon were calculated.The influence the variables,including but not limited to the voltage,diffusion rate and current density of electrons,on the field reversal was investigated. The peaks of electron and ion densities,2. 4 × 10^10cm^-3,locate at the discharge-cell center; however,the ion density is much higher than the electron density in the cathode sheath. Depending strongly on the ratio of the electron diffusion and flowing rates,the axial field-reversal occurs,accompanied by potential-barrier formation at the center,because the potential in negative glow region is higher than the anode potential. Moreover,an increase of the voltage fastens the electron diffusion rate,and enhances both the field reversal and potential-barrier formation.
出处
《真空科学与技术学报》
EI
CAS
CSCD
北大核心
2015年第12期1420-1426,共7页
Chinese Journal of Vacuum Science and Technology
基金
国家自然科学基金项目(11205046)
河北农业大学理工基金项目(LG20140503)
河北省高等学校科学技术研究项目(YQ2013017)
关键词
空心阴极放电
流体-亚稳态原子模型
电场反转
粒子流密度
Hollow cathode discharge
Fluid-metastable atoms transport model
Electric fieldreversal
Particle flow rate
