Boundary layer formation in a flow of collisionless magnetized plasma

In the devices, such as plasma accelerators, plasma opening switches, plasma focus, plasma with magnetic field frozen in it moves along electrodes in the direction transversal relative to magnetic field. Near the plasma-surface interface a boundary layer arises where ions colliding with the wall are partly absorbed in an electrode matter and partly go out back to the flow with a loss of momentum and energy. A self-consistent collisionless interaction of the reflected ions with the basic flow ions results in ion gyration of the basic flow towards the electrode. An instability arises, because of which more and more ions collide with the wall leading to anomalous “viscosity” on a scale of ion Larmor radius. The paper solves one-dimensional problem of the near-electrode layer in low density plasma using the particle-in-cell method and assuming that all values depend only on the coordinate perpendicular to the electrode surface. It is shown that the ion scattering on electrode leads to plasma flow deceleration at a distance of ∼0.5 Larmor radius calculated by plasma flow velocity in a wide range of plasma flow Alfven-Mach numbers.