Effect of ExB drift on the plasma flow at the magnetic presheath entrance

The formulation of boundary conditions (BCs) at the magnetic presheath entrance (MPE) is an important issue, as these define the particle and energy fluxes to the material surface. In addition, these BCs are necessary for fluid codes simulating different plasma devices. There exists a number of papers where the influence of the ExB drift on BCs was investigated analytically, or using particle-in-cell (PIC) simulations. In the majority of these works, the normal gradient of the electric-field component parallel to the wall was neglected, or just accounted partially. Moreover, in the one-dimensional PIC simulations the parallel component of the electric field was considered to be constant (non-vanishing at the wall). In the present work, taking into account the above-mentioned gradient, we derive a simple analytical BC at the MPE in the presence of the ExB drift. Our analytical result is checked against self-consistent 1d3v PIC simulations of the collisional magnetized plasma-wall transition (PWT). The simulation region includes the collisionless plasma (Debye) sheath, the collisionless magnetized plasma presheath, and the collisional presheath. The latter is assumed to be governed by ion-neutral collisions. Different profiles of the imposed paralell electric field have been considered. This work was performed within Project P1 of the Association EURATOM-OeAW. (orig.)