Determination of plasma potential from the ionic part of the volt-ampere characteristics of an electric probe

A method is proposed for determining plasma potential from the ionic part of the volt-ampere characteristics of an electric probe. Model calculations and experimental results indicate that the proposed method is sufficiently reliable and can be used in cases where the application of the usual methods is impossible or cumbersome. The method can be used most successfully in the case when a magnetic field is present, since a magnetic field reduces the electron current to the probe but has little effect on the ionic current.