Oscillations of a Cylindrical Plasma

Abstract

The natural modes of oscillation of a cylindrical plasma of finite density at zero pressure in a longitudinal magnetic field are examined. When one considers frequencies well below the electron plasma and electron cyclotron frequencies, there appear in two limiting cases hydromagnetic waves, and waves whose natural frequencies are close to the ion cyclotron frequency. This cyclotron frequency resonance occurs when the wavelength of the oscillation in the $z$ direction is short compared to the wavelength for light in vacuo corresponding to the root square sum of the ion plasma frequency and the ion cyclotron frequency.