ABSTRACT
The Langmuir probes have been used as a simple measurement method for obtaining the local plasma parameters. The technique is well known and has been discussed in detail by several authors throughout the literature [1-5]. Here we briefly summarize the method, its usefulness, and the equations necessary for determining the plasma parameters. We also present results of an actual probe characteristic taken from the experiment. The probe measurement method consists of inserting into the plasma a small metallic electrode or probe of known area whose shapes are generally planes, cylinders, or spheres. In our experimental work, we mainly employ planar Langmuir’s probes. The Langmuir probe measurement has the following advantages:
a. Local measurements can be made. This point is the most important because almost all other measurement techniques, such as spectroscopy or measurements based on microwave propagation, give information averaged over a large plasma volume.
