Disturbance Phenomena in Probe Measurement of Ionized Gases

Abstract

This paper is concerned with disturbance phenomena occuring when a probe is immersed in plasma.
There are two types of disturbance, i.e., one independent of probe potential and one which depends upon it. The former (inherent) disturbance has three effects which are classified: Asymmetrical effect, formation effect of transition region, and the scattering effect. The latter (incidental) depends on either the negative probe or the positive probe. In the negative probe, penetration of ion sheath into surrounding plasma is characteristic. In the positive probe, there is an unexpected change of electron current, as a result of drainage of electron, which is observed with rise of positive probe voltage.
The mechanism of collection of ion and electron on probe is also explained in terms of these disturbance effects.