Effect of a non-uniform magnetic field on two ion species plasma-wall transition

Abstract

Fluid theory has been employed to investigate the magnetized plasma-wall transition properties for two ion species plasmas with a uniform background of neutral gas density in the presence of an external magnetic field. The external applied magnetic field is parallel to the surface and its magnitude varies in the direction perpendicular to the surface. The governing equations of ion and electron fluids include ionization and collision with neutral atoms. A comparative study of transition parameters for non-uniform and uniform magnetic fields is performed at equal values of the magnetic flux density at $x = 0$. This study shows that the sheath region shrinks for the non-uniform magnetic field case, essentially in reason of the lower value of the average magnetic field intensity in the plasma-wall transition region. We introduce a figure of merit to quantify the non-uniformity of the magnetic field $(B_{\mathrm{max}}-B_{\mathrm{min}})/B_{\mathrm{max}}$, and show that for its value 0.21 it is possible to model the plasma-wall transition region considering the magnetic field as uniform and equal to its average value. Furthermore, we find that the density distribution of electrons close to the surface deviates from the Boltzmann distribution due to the influence of a strong magnetic field.

Effect of Permittivity of Plasma Medium on the Particle Properties and Electric Field in a Magnetized Plasma Sheath

“…Once the distribution functions are calculated, then electron and ion densities are calculated using (6) and the space charge density is (7) The electrostatic potential is obtained by solving the Poisson's equation…”

“…The behavior of plasma at material wall of a container is always a fascinating event which is one of the olderst problems in plasma [1] and is still not fully understood [2][3][4][5][6][7]. A thin layer that is formed close to a wall facing plasma and has sharp gradients is known as the plasma sheath.…”

Study of plasma sheath in the presence of dust particles in a magnetic mirror-like field configuration

“…These studies are mostly carried out in an external uniform magnetic field oblique or parallel to the wall. Such a study in a non-uniform external magnetic field is a very new and fascinating area of research [11,25]. The first study in this area was carried out in a magnetic field that increases linearly along the sheath having a direction parallel to the wall in an electron-ion plasma.…”