Simulation of dynamics of rotating weakly ionized plasmas

Abstract

In this paper, we present a simulation study on the generation of rotating gas in a cylindrical chamber, which contains weakly ionized gas with charge to neutral density ratio (10−6−10−3). In this chamber, a radial current component of current density, Jr, is driven by an external electric potential difference between the inner and the outer radial boundaries, and a static magnetic field B0 is imposed in the axial direction. The charged particles are accelerated in the azimuthal direction by the Lorentz force Jr×B0. The neutrals then gain an azimuthal acceleration through ion–neutral collisions. The centrifugal force increases as the azimuthal speed increases. In the simulation, a strong centrifugal acceleration of 1011 m/s2 is achieved with an azimuthal speed of 105 m/s. A density gradient is developed to balance the centrifugal force, and the density at the outer radial boundary can reach 1025−1026 m−3.