A.N. Kargin

Calculation of high-frequency electronic bombardment power of magnetron cathode is described. It is known, that in a cavity magnetron un-der action of high frequency field emitted by the cathode electrons are sorted on electrons of «suitable» phase and electrons of «unsuitable» phase. «Unsuitable» electrons come back to the cathode with the increased energy which is received from the high frequency field. The anal-ysis of this phenomenon is based on the averaging method offered by P. Kapitsa for calculation of electron trajectories in a magnetron. In present article the expression which allows to calculate cathode losses at known parameters of the device is received. High-frequency ca-thode losses are determined by the form of a cell of interaction, a magnetic field value and a high frequency voltage amplitude on the resonator gap. Power of the cathode bombardment increases with growth of an anode current in a - 3/2 - degree and can make 5÷10 % from anode electronic bombardment power. Necessary characteristic resonator impedance is defined by computer simulation of the resonator by HFSS code. For this purpose resonant frequency shift is defined while the revolting dielectric solid in area of a homogeneous electric field of the resonator is entered. For typical magnetron designs at known dielectric geometry under the resulted formulas it is possible to calculate characteristic resonator impedance and then the power of cathode back bombardment. Results of calculation are compared to known experimental data of 2J32, 2J42 magnetrons and with simulation results of VMS-1873 magnetron by the use of CONDOR code. Close fit with experimental results is shown, that confirm reliability of cathode losses calculations with the suggested method.