Measurement of Electron Density and Temperature by Means of Contamination-Free Probe

In plasma diagnosis by means of a Langmuir probe, contamination of the electrode is a quite serious problem. In order to get reliable data of space plasma, cleaning of the electrode is an essential requirement. The instrument which is not influenced by the electrode contamination must be developed. In this paper we recommend two types of probes; one is a glass-sealed Langmuir probe and the other is an electron temperature probe. These two probes are free from contaminaton effects and can give reliable electron density and temperature in the ionospheric plasma. Finally this paper briefly discusses the application of the Langmuir probe to polar ionosphere study