Effects of collision and ion Mach number on magnetized plasma sheath with two species of positive ions

Abstract

We study the effect of collision and ion Mach number in a magnetized plasma sheath having two species of positive ions using fluid model. It is assumed that both the ions are singly ionized and in thermal equilibrium, and the electrons obey Boltzmann distribution. Our work signifies that the collision greatly affects the ion densities, which explicitly affect space charge density, net current density and the transverse drift of ions. On increasing the collisional frequency, ions accumulation point and current saturation point shift towards the sheath entrance (away from the wall). The ion Mach number affects potential profile and velocity profiles of both ion species. The magnitude of wall potential increases from 34 V to 45 V with the increase in ion Mach number from 0.3 to 0.9. Furthermore, it is shown that the effect of collisional force and Lorentz force is reduced at the sheath entrance by increasing the ion Mach number, which helps to control the flux of particles, momentum flow and energy flow towards the wall.

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

“…Foroutan [28] presented the one-dimensional fluid simulation to investigate the dynamics of an electrostatic sheath for two ion species plasma with dust grains. In recent years, the authors also worked on two ion species plasma in the presence of a uniform oblique magnetic field and collision term using kinetic and fluid models [29][30][31]. Singha et al [32,33] carried out an experiment to study the effect of a non-uniform oblique magnetic field and biasing voltage on presheath and sheath structures.…”

Variation of Velocity of Ions in a Magnetized Plasma Sheath for Different Magnetic Field

“…Once the plasma-wall interaction is well understood it will be possible to control heat loading, energy transfer and particle flow towards the wall and overall bulk plasma behavior [4,5]. The plasma sheath is one of the oldest problems in plasma [3,6] and in recent years, the sheath formed between magnetized plasma and a particle absorbing wall has received a considerable amount of attention [7][8][9][10][11]. Irrespective of this, plasma sheath is significantly influencing the charged particles and the energy flux to the wall, which in turn considerably modifies the absorption, emission impurities and all other characteristics in the plasma [1,11].…”

“…The plasma sheath is one of the oldest problems in plasma [3,6] and in recent years, the sheath formed between magnetized plasma and a particle absorbing wall has received a considerable amount of attention [7][8][9][10][11]. Irrespective of this, plasma sheath is significantly influencing the charged particles and the energy flux to the wall, which in turn considerably modifies the absorption, emission impurities and all other characteristics in the plasma [1,11]. In typical boundary layer problems the sheath region is of several electron-Debye lengths, which is much smaller than the characteristic extension of the plasma.…”

Effect of collisions on the plasma sheath in the presence of an inhomogeneous magnetic field

“…On the other hand, the ion-neutral collision plays an important role in the formation and stability of sheath structure. The collisional plasma sheath in the presence of a magnetic field has been investigated by many researchers [3,4]. It has been observed that the collisional force affects the distribution of ion density and drift velocity [4][5][6].…”

“…The collisional plasma sheath in the presence of a magnetic field has been investigated by many researchers [3,4]. It has been observed that the collisional force affects the distribution of ion density and drift velocity [4][5][6]. The study of collisional plasma sheath has shown that collision alters the condition for the formation of the sheath.…”