Gas rotation in a stratified positive column of discharge in longitudinal magnetic field

Joint Institute for High Temperatures (IVTAN), Russian Academy of Sciences - Moscow 125412 Russia

Received: 22 April 2013
Accepted: 23 July 2013

Abstract

The problem of gas rotation in a positive column of electric discharge with immobile striations in a longitudinal magnetic field is considered. This rotation around the axis of discharge is caused by the action of Ampère forces due to an eddy electric current that arises under conditions of noncollinear gradients of the electron concentration and temperature. In a stratified discharge, the plasma density and temperature are periodic functions of the longitudinal coordinate. The plasma density profile is described by the well-known Schottky model for a regime of ambipolar diffusion. In immobile striations, the velocity of rotation is limited by the two-dimensional gas viscosity. Formulas for the average velocity of gas rotation as a function of plasma parameters in striations are obtained and compared to formulas for the velocity of rotation of dusty plasma structures under the action of ion drag forces. The problem of gas rotation in moving striations in a longitudinal magnetic field requires special consideration, since the acceleration of gas rotation in this case has to be taken into account.