Structure of presheath-sheath in magnetized electronegative plasma

Abstract

The structure of an electronegative discharge is investigated in the presence of an oblique, uniform, and constant magnetic field. For different magnetic field strengths, the densities of the positive ion, electron, as well as negative ion have been calculated. Furthermore, the profiles of positive ion’s velocity and electric potential are obtained. Under high values of electronegativity and for sufficiently cold negative ions, different magnetic field values constitute three types of discharge structure. For a very small magnetic field strength, a uniform structure is formed; for an intermediate magnetic field, a stratified multiple layer structure emerges, which is followed by electric potential oscillations; while for an intense magnetic field, these oscillations disappear. The flux of the positive ion reaching the cathode as a function of the magnetic field strength is also obtained and the result is compared with the electropositive discharge.