Effect of Cathode Geometry on Magnetically Coupled Hollow Cathode Plasma Source

Full text: A direct current (DC) plasma source consisting of hollow cathode geometry and a constricted anode is presented. The effect of a hollow cathode geometry on radial density distribution of a magnetized plasma column has been studied in a low-pressure (approximately 1.4 Pa) argon discharge. The plasma column is characterized using Langmuir probe and the radial density distribution for two different "inside" profiles of a hollow cathode is discussed. Probe measurement indicates that a conical-profile hollow cathode produces a plasma column with centrally peaked plasma density whereas a cylindrical-profile hollow cathode forms plasma column with off-centred density peak. Thus overall dynamics of perpendicular and oblique cathode sheaths behind the sustenance of magnetized plasma column has been discussed. (author)