Shear Stabilization of a Collision-Dominated Plasma

Abstract

The effect of magnetic shear on the stability of the electron-neutral collision-dominated plasma is determined by introducing the shear directly into the basic macroscopic equations which describe the plasma. The dispersion equation for the family of perturbations of helical form is reduced to a stability criterion which defines the onset of such perturbations. An equation describing the form of the zero-order plasma density profile, which is required for the numerical evaluation of the stability criterion, is derived. The theory is applied to a hollow plasma column. Theoretical radial profiles of the zero-order plasma density are computed and verified experimentally. The experimentally determined profile of the first-order plasma density guides the choice of the mathematical model of the perturbation which is used in the stability calculation. The hollow plasma column is found experimentally to possess a regime between the quiescent and turbulent states where perturbations of helical form exist. Mode switching between the single and double helical perturbations is found. The plasma is predicted to be stabilized when the magnetic shear is in the opposite sense to the plasma perturbation, and destabilized in the other case. These predictions are experimentally verified within the over-all accuracy of experiment and theory. 0 1 1--h-x © X X A 0 © m-2 ©© + Pressure (Torr)

Current-convective instability of a gas-discharge plasma

“…ТКН полого плазменного столба в винтовом магнитном ноле с «ши-ром» подробно исследована Рейнольдсом и Холтом 114 . Они показали экс-периментально и теоретически, что помимо перекрещенности магнитных силовых линий с азимутальным полем Η φ существенно меняется профиль стационарного распределения плазмы, что, в свою очередь, влияет на его стабильность.…”