Macroparticle filtering of high-current vacuum arc plasmas

The transport of vacuum arc plasmas through a 90o curved magnetic macroparticle filter was investigated using a high-current pulsed arc source with a carbon cathode. The peak arc current was in the range of a few kA, exceeding considerably the level of what has been reported in literature. The main question investigated was wether magnetic macroparticle filters could be scaled-up and simultaneously maintaining the transport efficiency of small filters. In front of the cathode we found arc-current-depending total ion saturation currents in the range from 10 to 23% of the arc current. The best transport efficiency was 25% (time integrated output / time intgrated input) at a duct wall bias of 25.5 V and at an axial magnetic field of about 100 mT. This is comparable to what has been observed with other, low-current filters.