Abstract

A grid anode glow discharge is a promising source of plasma for absorbing electromagnetic radiation. This paper presents an experimental study of a large-area dc grid anode glow discharge in helium. The behavior of the helium discharge was studied at pressures in the range of 2–50 Torr and discharge voltages up to 1500 V. It was observed that the discharge completely covered the cathode surface at helium pressures of 2–25 Torr. For all pressures, voltage increases as current increases, which typical for anomalous glow discharge. The electron density in the post-anode plasma and attenuation of the microwave radiation by the plasma were measured using microwave diagnostic methods. It was found that the electron density and degree of helium ionization decrease with increasing helium pressure and increase with increasing discharge current. The electron density in the post-anode plasma is not high: n_e is about 2 × 10⁹–6 × 10¹⁰ cm^–3, corresponding to a degree of ionization of about 10^–7–10^–6. It is shown that the maximum attenuation of 10-GHz microwave radiation is about 6% at a helium pressure of 2 Torr.

中文翻译：

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氦气中大面积直流网格阳极辉光放电

摘要

栅极阳极辉光放电是用于吸收电磁辐射的有前途的等离子体源。本文介绍了氦气中大面积直流栅极阳极辉光放电的实验研究。在 2-50 Torr 的压力和高达 1500 V 的放电电压下研究了氦放电的行为。观察到在 2-25 Torr 的氦压下放电完全覆盖了阴极表面。对于所有压力，电压随着电流的增加而增加，这是异常辉光放电的典型特征。使用微波诊断方法测量阳极后等离子体中的电子密度和等离子体对微波辐射的衰减。发现电子密度和氦电离度随着氦压的增加而降低，随着放电电流的增加而增加。n _e约为2 × 10 ⁹ –6 × 10 ¹⁰ cm ^–3，对应的电离度约为10 ^–7 –10 ^–6。结果表明，在 2 Torr 的氦气压力下，10-GHz 微波辐射的最大衰减约为 6%。