Global modes in spatially limited plasmas

Linear electrostatic modes are discussed in spatially bounded plasma. In particular, some results are presented for low-frequency global modes in a magnetized rotating electron plasma. Also, in a two-component electron-ion plasma flowing in the direction of the magnetic field vector, and having a radial density gradient and the radial variation of the flow, analytical solutions are presented for a class of density and flow profiles. The solutions represent global modes that are twisted around magnetic lines and vanish at the plasma axis and at the boundary. More details are given for the behavior of electrostatic drift and ion sound waves in plasmas with an equilibrium density gradient in both the directions perpendicular and parallel to the ambient magnetic field. In spatially unlimited plasmas, and in Cartesian geometry, the mode amplitude is calculated for several profiles of the equilibrium density. Exact analytical solutions are found. Cylindric plasmas bounded in the radial direction and bounded or unbounded in the axial direction are also investigated in the presence of equilibrium density gradients in both the radial and axial directions. Exact analytical solutions are found in terms of the Kummer confluent hypergeometric functions, describing standing oscillatory patterns in the radial and axial directions, associated with the drift mode propagating in the poloidal direction.SCOPUS: cp.p