一、引言 近来,尽管等离子体诊断技术有了很大发展,古老的朗缪尔探针由于结构简单,使用方便且有较好的时间空间分辨,至今仍作为基本诊断工具而广泛使用。但是,简单的朗缪尔探针理论只适用于中等密度(L》r》λD,L是平均自由程,r是探针半径,λD是德拜长度),对于低密度等离子体(r≤λD),朗缪尔探针理论复杂得失去了实用价值。本文将给出两个适合于低密度情况下的简单公式,并介绍一种实验中所用的静电能量分析器。 I. INTRODUCTION Recently, despite the great development of plasma diagnostics, the ancient Langmuir probe is still widely used as a basic diagnostic tool due to its simple structure, easy to use and good time and space resolution. However, the simple Langmuir probe theory applies only to medium-density (L “r” λD, where L is the mean free path, r is the radius of the probe and λD is the Debye length) and for low-density plasmas ), Langmuir probe complexity has lost its practical value. This article will present two simple equations suitable for low-density cases and introduce an electrostatic energy analyzer used in the experiment.