Effective cathode voltage and ion current measurements in a Vacuum Arc with a Black Body Electrode Configuration

A new type of Vacuum Arc with a Black Body Assembly (VABBA) was studied to produce a directed plasma flux. The arc was contained in a closed cathode-anode assembly which confined and evaporated macroparticles (MPs) while the plasma was extracted through small anode apertures. Arc currents were I=175-250 A and arc time 90 s. The effective cathode voltage U_cef was determined by calorimetrically using a thermocouple probe. The ion current I_i was measured by an electrical probe. It was observed that U_cef increased with time from ~6.5 V for cold anodes (i.e for a conventional cathodic arc) to a steady state value of ~11.2-11.7 V when the anode was sufficiently hot and the arc operated in the VABBA mode. I_i decreased with distance from the anode. The expanding Cu plasma flux from a VABBA with a shower-head anode produced thin films on glass substrates with a deposition rate of 3μm/min.