Study of short wavelength instabilities the confinement of a collision dominated plasma by a rotating magnetic field

Abstract

A collision dominated plasma confined by a rotating magnetic field is stable if f>or approximately=0.02 vi where f is the frequency of rotation and vi the ion collision frequency. Short wavelength perturbations are the most difficult ones to stabilize. Growth rates of parametric instabilities are shown to be so large as to make impossible any attempt to use a frequency much lower than the above limit. A simple interpretation of a wide region of instability, which cannot be ascribed to any parametric instability, is given in terms of an equivalent negative resistance.