Excitation of upper-hybrid waves by a rotating relativistic electron beam in a plasma-filled large-orbit gyrotron

摘要

A large-orbit gyrotron may operate at higher beam currents if one introduces a plasma in its interaction region. The plasma, however, is unstable to an upper-hybrid electrostatic perturbation driven via cyclotron interaction by the rotating relativistic electron beam. The growth rate of the instability is comparable to the growth rate of the cyclotron maser instability when the plasma frequency is of the order of the electron cyclotron frequency.