Plasma parameters in some industrial vacuum arc deposition systems

The interelectrode plasma generated at the same conditions (discharge atmosphere, pressure, arc current) in two industrial arc devices was studied by optical emission spectroscopy. The devices were operated with titanium cathodes in vacuum, N2 or a N2/C2H2 mixture. Voltage-current characteristics of the discharges were also investigated. Results of spectral diagnostics indicated on the partial local thermodynamic equilibrium conditions in the sources. From relative emission intensities of the atomic and ionic species, the electron density and the relative concentration of titanium species were evaluated. The coherence of the results derived from the spectroscopic measurements and those obtained earlier by using other techniques was noted.