The characteristics of an ion flow from a cathode spot of a vacuum arc

The aim of this work is to define the characteristics of an ion flow onto a cathode out of plasma of a vacuum arc. The results of investigating some interesting features of ion generation from the spot region are also presented. To study the energy spectrum and the mass structure of an ion flow a single-channel energy-mass analyzer has been used. The ion flow got into the input of the analyzer through the hole in the film cathode. The hole in the cathode film has been burnt by the cathode spots during the process of the arc combustion. It has been established that there is a high-energetic ion flow onto the cathode with a maximum intensity of about 75 eV. The width of the energy distribution of the ions falling onto the cathode is less than the width of the energy distribution of the ions falling onto the anode. The difference between the energy of the ion flow onto the cathode and the energy of the ion flow onto the anode is about 25 eV and is close to the potential drop on the arc. For the ion flow onto the cathode at different multiplicity of the charges the peaks of intensity are located at equal values of the energy per charge. It is also established that during the process of the arc combustion at the decreasing of the general arc current the ion flow onto the cathode is increasing, and at the increasing of the general arc current the ion flow on the cathode is decreasing