Sheath formation in an oblique magnetic field - some comments on length scales and source terms

6th International Workshop & Summer School on Plasma Physics 2014

Gyergyek, T.^1,2 ; Kovai, J.^2

University of Ljubljana, Faculty of Electrical Engineering, Traka 25, Ljubljana

1000, Slovenia^1

Joef Stefan Institute, Jamova 39, Ljubljana

1000, Slovenia^2

关键词: Characteristic length;    Electrode surfaces;    Ionization mechanisms;    Magnetic field line;    Magnetized plasmas;    Nonphysical oscillations;    Oblique magnetic fields;    One-dimensional fluid model;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/768/1/012005/pdf
DOI  :  10.1088/1742-6596/768/1/012005

来源: IOP

【 摘 要 】

A one-dimensional fluid model is presented and used for the analysis of the potential formation in front of a negative, large, planar electrode immersed in magnetized plasma. The magnetic field lines can form an arbitrary angle with the electrode surface, with the exception that they must not be completely parallel to the surface. The model includes elastic ion collisions and 3 source terms that describe ionization mechanisms. If the exponential source term is used, the pre-sheath is longer than in the case of the constant source term. The zero source term results in qualitatively different solutions that may even exhibit nonphysical oscillations. The problem involves 4 characteristic length scales. Any of them can be used for the normalization of the space coordinate and this has no effect to the solutions.