Observations of a potassium ion plasma in a Q-machine with mirror magnetic fields located at the hotplates indicate that a strong localized radial electric field is formed at the hot¬plate edge, producing both ion confinement and a rotating high-velocity annulus in the column. The plasma equilibrium formed can be adequately described by an isothermal fluid model that includes ion viscosity and the inertia associated with the column rotation.nWhen the midplane magnetic field Bo on the axis exceeds 300 G for all measured densities, azimuthally propagating waves are observed which are located at the edge of the rotat¬ing annulus. These waves are identified as transverse velocity shear excited modes by comparison of the data with the predic¬tions of the "velocity jet" model of Perkins and Jassby with regard to frequency, mode localization, and correlations between the perturbed density and potential.
展开▼
