Self-sustaining secondary emission in magnetron guns, beam modulation and feedbacks

Problems of magnetic insulation violation inside a vacuum coaxial diode with dense electron flow are considered. The numerical model of nonstationary nonuniform secondary electron emission provoked by primary low-intensity beam from a cathode was developed. The results of computer simulations of electron cloud formation due to nonlinear azimuthal instability under the condition of strong nonuniform secondary self-sustaining emission are described. The existence of an instability with transverse quasistationary leakage current of a few percent of Child-Langmuir current and rotating states of electron flow has been shown under conditions of conservation of full power and full momentum of the system