Abstract: Plasma beam apparatus and method for the purpose of vacuum processing temperature sensitive materials at high discharge power and high processing rates. A gridless, closed or non-closed Hall-Current ion source is described which features a unique fluid-cooled anode with a shadowed gap through which ion source feed gases are introduced while depositing feed gases are injected into the plasma beam. The shadowed gap provides a well maintained, electrically active area at the anode surface which stays relatively free of non-conductive deposits. The anode discharge region is insulatively sealed to prevent discharges from migrating into the interior of the ion source. Thin vacuum gaps are also used between anode and non-anode components in order to preserve electrical isolation of the anode when depositing conductive coatings. The magnetic field of the Hall-Current ion source is produced by an electromagnet driven either by the discharge current or a periodically alternating current.