Triple Probe Method Research Articles

Floating Multiple Probe Systems for Plasma Measurements

A new analysis of the current voltage characteristic of a floating double probe system is given, showing that the electron temperature must be estimated from measurements at the point of inflection of the characteristic if positive ion movement contributes to the probe circuit current. Temperature measurements will still be in error if the rates of variation of positive ion current to the two probes are not closely similar as the potential difference between them is varied. An alternative experimental technique is described which will yield correct temperature estimates in such circumstances, and is simpler and less perturbing to the plasma than the floating triple probe method.

Asymmetrical Triple Probe Method for Determining Energy Distribution of Electron in Plasma

A new probe method is proposed. This method is an improvement of the floating triple probe method, which was proposed by us in a previous paper. In this method, the dimension of one operating probe is different from the other, so that the smaller probe behaves as the single probe. Thus, the measurable range of electron energy can be extended as much as that in the single probe method. The asymmetrical triple probe and double probe methods are verified experimentally. The asymmetrical triple probe method has a merit that a disturbance, which is inevitable in the single probe method, can be eliminated in this method. The electron energy distribution obtained by the new probe method is not always in accord with that obtained by the usual single probe method. The hump often observed at high energy range in the single probe method does not appear in the new method, illustrating that the latter is free from erroneous estimation due to the disturbance.