Fixed-bias floating double-probe technique with simple Langmuir-probe characteristics.

A new floating double-probe method is presented which has advantages over other floated-probe systems heretofore described in the literature. The method utilizes two electrodes, one of constant area and the other with a variable area, and the two-electrode configuration is separated by a fixed bias voltage. The current-voltage characteristics of the new technique, which are generated by varying the area of one electrode, are identical to those of a simple Langmuir probe, thus coupling all the advantages of a floated-probe system with the simple analysis scheme generally applied to the Langmuir probe for the determination of plasma density and temperature.