大面积等离子体片密度分布分析

Density distribution of large planar plasma sheet

利用空心阴极放电产生了尺寸为60 cm×60 cm×2 cm的大面积等离子体面.在实验室条件下对大面积等离子体片的密度分布进行了测量.由于高压放电脉冲脉宽较短,实验中改变了测量方法,同时,在中等磁场影响下,为了得到真实的等离子体密度,进行了必要的数值修正.在放电电流为1—6 A时,测量了二维的电子密度分布.另外,测量并讨论了其他环境参数对等离子体密度的影响.电子密度的分布情况对与微波波束切换相当重要.由空心阴极增强型放电产生的大面积等离子体面具有反射X波段(8—12 GHz)微波需要的足够稠密的电子密度和足够均匀的密度分布,这是等离子体面在雷达系统中取代金属面板的有利条件.

A large plasma sheet with a size of 60 cm×60 cm×2 cm is generated in an apparatus with a hollow cathode.The electron density distribution of the large area plasma sheet is measured.Since the duration of high voltage pulse is short,we change measurement methods.Besides,modification is used for electron saturation current to get the real density.The two-dimensional electron density and electrical field distribution are calculated at discharge currents ranging from 1 to 6 A.Meanwhile we discuss other parameters related to density distribution.The electron density distribution is important for plasma sheet to steer microwave.It is encouraging that the large area plasma sheet generated by the hollow cathode is uniform and has sufficient electron density to reflect X-band（8-12 GHz） microwaves.