The behaviour of vacuum arc discharges at hydrogen impregnated electrodes

This paper is concerned with experimental studies of the behaviour of vacuum arcs at hydrogen impregnated electrodes. The arc discharges were analysed by high-speed photography, registration of arc voltage and current and measurements of the erosion upon dependence of the level of impregnation for a wide range of arc currents. The results show that impregnation of electrodes with hydrogen reduces the erosion rate, causes smaller crater dimensions, changes the macroparticle size and decreases the current per spot. For a given current, the arc voltage depends on the degree of impregnation with hydrogen. The voltage of low current arcs decreases with increasing impregnation. Furthermore, the arc discharge burns more stably on impregnated electrodes. The total erosion rate decreases significantly due to the reduction of the droplet fraction. The spot movement is mainly faster than on nonimpregnated electrodes.