Oscillations of the collisionless sheath

Abstract

An Eulerian-Vlasov code is used to study the properties of a collisionless sheath with grazing incidence of the magnetic field. In the case where the ion gyroradius is large compared to the Debye length, the electrons, frozen by the magnetic field lines, have to move rapidly along the magnetic field B in their attempt to follow the ions gyrating perpendicular to B. Below a critical angle, the electrons moving parallel to B can no longer follow the gyrating ions and low-frequency oscillations appear in the system.