ИСТИНА

An axially symmetrical rf magnetron discharge in argon with a small admixture of air and in air was studied. The plane loaded electrode was equipped with a ring-shaped dielectric insert. Design features of the electrode and of the magnetic system allow the discharge ring to be located in the region where the electric and magnetic field lines are not perpendicular to each other. It has been revealed that in this case the glowing plasma ring is sectionalized. Up to 10 long-living plasma bunches were observed. They equidistantly locate along the discharge ring and may either rotate around the discharge axis or remain motionless. Both the discharge power and the working gas pressure are quite different from those proper to dc and high-power impulse magnetron sputtering discharges with spokes.