微空心阴极放电时空特性

Temporal and spatial characteristics of micro-hollow cathode discharge

为了揭示微空心阴极放电的放电机理，利用流体模型研究了矩形微空心阴极放电的时间和空间分布特性。在氩气环境下计算得到了压强为1．3×10Pa时电流、电势、电场、电子和离子密度等随时间的发展变化。结果表明，整个放电过程分为四个阶段，即预放电阶段、电场由轴向向径向转换阶段、电流缓慢增长向空心阴极效应过渡阶段和稳态放电阶段。稳态放电时出现明显的空心阴极效应，阴极位降区存在很高的径向电场和较高的电子平均能量，而负辉区径向电场很弱，电子平均能量较低，电子和离子密度峰值出现在负辉区，二者数值基本相等，而在阴极位降区离子密度远高于电子密度。

In order to explore the mechanism of micro-hollow cathode discharge, the temporal and spatial characteristics of rectangular micro-hollow cathode discharge at 1.3× 10 Pa are investigated using a two-dimensional fluid model. The current, e- lectric potential, electric field, charged particle density and mean electron energy are calculated temporally. The results show that the whole discharge consists of four stages, the pre-discharge stage, the transition stage from axial electric field to radial electric field, the transition stage to the ＂hollow cathode effect＂ and the stable discharge stage. Hollow cathode effect exists at the stable stage. Strong electric field and high mean electron energy exist in the cathode fall while high density and quasi-neutral plasma in the negative glow. The peak value of electron density can achieve 10^14 cm -3 , and the electron temperature levels range from sev- eral eV to tens of eV.