STUDIES ON THE MEASUREMENT OF PLASMA PARAMETERS BY MEANS OF THE RF PROBE METHOD

The RF impedance of a probe in collisionless plasmas has been studied. Numerical results of the RF impedance vs. the probe bias potential for various ωp/ω are given, where ωpand ω are the angular frequencies of the plasma and the applied RF signal, respectively. Collision effect on these RF impedance characteristics is also analyzed and discussed. A new method based on this study in order to determine the electron temperature and the electron density of the plasma is proposed. This proposed method has been also assured in a different manner by measuring the electron temperature and the electron density employing a usual Langmuir single probe method simultaneously. Experimental results agreed with the theory for the gas pressures up to 3 Torr where the electron mean free path is smaller than the probe radius by the factor of about 1/5. © 1979 IOP Publishing Ltd.