Transport of vacuum arc plasmas through magnetic macroparticle filters

Vacuum arc plasma deposition combined with magnetic filtering of the plasma to remove macroparticles is a promising technique for the production of metallic, compound and hard amorphous carbon thin films. High efficiency of the magnetic filter is a crucial parameter for the application of this technique. We report investigations of the influence of different filter designs, magnetic field configurations and electric potentials on the filter efficiency. We analyse the transport mechanisms on which the flow of plasma through the filter is based, and describe and discuss the occurrence of instabilities in magnetic filters. With an optimum filter arrangement we were able to obtain a filter output of 25% of the total number of ions produced by the vacuum arc discharge.