Modeling of Electrostatic Sheath in Electronegative Magnetized Dusty Plasma in the Presence of Monoenergetic Electrons

In this article, we present a new 3-D, collisional, stationary, and magnetized plasma sheath model based on fluid equations. Numerical calculations in weakly electronegative oxygen plasma at low pressure containing graphite dust grains with a size distribution have been carried out. The obtained results reveal that the sheath thickness decreases as the magnetic field increases. However, the relatively more energetic electrons than ions are less affected. The electrostatic sheath thickness increases as the maximum dust radius increases. However, the variation of the lower limit of the dust grain radius does not exhibit any effect on the electrostatic sheath properties. Furthermore, the presence of dust grains increases the electrostatic sheath thickness and modifies its physical parameters. Nevertheless, for a small fraction of dust grains, there is no effect on the electrostatic sheath structure. A remarkable widening of the electrostatic sheath is observed due to an increase in the number of monoenergetic electrons. When the ion density varies from 108 to
$10^{11} \text {cm}^{-3}$
, the normalized electrostatic sheath thickness changes from 38.58 to 57.13 Also, an increase in electron temperature causes an increase in the electrostatic sheath thickness. Furthermore, it can be illustrated that the sheath thickness becomes smaller as the discharge pressure increases. Finally, we have shown that in the case of a high electronegativity regime, the thickness of the electrostatic sheath decreases considerably.