The emission of plasma cyclotron waves in plasma filled backward wave oscillators

Summary form only given, as follows. It was found through computer simulations of plasma-filled backward wave oscillators that, within a certain range of magnetic field, the growth rate of beam-plasma cyclotron interaction is significantly larger than the conventional backward wave oscillation. This slow plasma cyclotron wave is emitted from plasmas only if it also satisfies the dispersion relation of a ripple-wall waveguide which couples the slow wave to the fast wave. This observation may be employed to interpret previous experiments which displayed a strong dependence of output power on the magnetic field