Wave angular momentum in nonneutral plasmas

Angular momentum and energy are added (or removed) when exciting a mode, such as a diocotron, Trivelpiece-Gould, or Dubin mode, and we discuss rates at which mode angular momentum and energy are added by applied fields. Excitation of a plasma mode is an effective way to transfer angular momentum and energy to the plasma because it is a resonant process. We relate this to recent experiments on compression and expansion of plasmas using a "rotating wall" field. We also calculate the torque on a Coulomb crystal which is phase-locked to a "rotating wall" field and describe phase oscillations and the maximum rate of acceleration which can be achieved.