The Cathodic arc is an intense source of highly ionised plasma ideal for depositing materials onto surfaces, and under some conditions, implanting these materials into a surface.
Research is under way into the basic physics and applications of cathodic arcs.
An amazing fact is that the temperature of the bright spot on the cathode surface, which is the source of the ionised material, is in excess of 40,000 degrees. The almost fully ionised plasma may be guided by magnetic fields which results in the formation of a beam of this plasma material. This has resulted in a fascinating area of plasma physics concerned with the behaviour of these plasmas being opened up. The photograph below shows fully ionised plasma streaming through a mask.