Coaxial Discharge under the Influence of a Magnetic Field

摘要

A quasineutral two fluid model is applied to a discharge formed between two coaxial cylinders under the influence of an axial magnetic field. The impact of the magnetic field on the plasma is studied and quantified by calculating the potential and density distributions in the system. It is found that the density distribution in the presheath deviates significantly from the Boltzmann relation for electrons due to the presence of the magnetic field. This occurs because B opposes the radial flow of charge. However, the field not only inhibits transport of charge to the walls, but also deflects both fluids, setting up currents in the system, which increase the externally applied field. This effect can alter the field topology in the discharge significantly and makes it necessary to solve for the magnetic field self-consistently in some situations. The relevant parameter range is identified and B is allowed to vary. The magnetic field's effects on the inherent asymmetry of this setup are also studied.