It is proposed to use a great body of vacuum arc plasma parameters measured in combination with a theoretical model of a current-carrying plasma jet for the determination of cathodic microjet parameters. The most probable values of microspot diameter and microjet current thus obtained lie in the range and I = 1 - 5 A, respectively. It is also shown that the mean ion charge variations observed can be essentially explained by a periodical variation of the ionization energy set with the atomic number of the cathode material.

An analysis of the ion charge distribution measurements in a vacuum arc plasma has been carried out. It has been demonstrated that, by using the Saha equation, one can determine the electron temperature Te and density Ne in the cathode spot plasma. It has also been shown that it is possible to estimate a microspot diameter d and a current density j in the microspot by applying a theoretical model. The values obtained for Te approximately=4-10 eV, Ne approximately=1026-1028 m-3, d approximately=0.2-0.5 mu m and j approximately=(1-30)*1012 A m-2 are in agreement with recent measurements.