Effect of rotation on plasma stability in the gas-dynamic trap

Abstract

The effects of the centrifugal force and finite Larmor radius on plasma stability in the gas-dynamic trap are considered. Estimates show that the stability is governed by the strong effect of the finite Larmor radius of fast particles. If this stabilizing mechanism does not operate, then the instability ceases to be exponential when the sheared plasma rotation becomes sufficiently intense. In this case, the potential perturbation amplitude increases according to a power law, and the instability threshold remains unchanged. These effects do not influence the stability of the first azimuthal perturbation mode in a plasma with a free boundary. But when the plasma is in good electrical contact with the conducting wall of the device and when the plasma density profile is not too peaked at the axis, the first mode is stabilized by the finite Larmor radius effect because of the radial variation of the perturbed electric field.