Vacuum arc plasma beam motion in curved magnetic fields

A theoretical model is presented for transport of vacuum arc generated metal vapor plasma through a magnetized quarter-tours duct used for filtering out macroparticles in order to deposit high quality thin films. The model utilizes a two fluid approximation which takes into account collisions among the plasma particles. It is found that centrifugal forces must lead to a charge separation generated field, that determines plasma drift in thecentrifugal force direction to the duct wall and give rise to ion loss. Another cause for plasma loss is the plasma pressure gradient. The plasma output flux is an increasing function of thr magnetic field strength. The plasma flux in the output plane is asymmetrically skewed to favor the outside half. A further asymmetry in the flux distribution in the direction of the torroidal axis of symmetry is introduced if ions of different charge states are present in the plasma.