Emission simulation and secondary electron emission measurement of the cathode in high-power continuous wave magnetron tubes

Energy and local distribution of electron around the cathode have been simulated in a 30kW continuous wave magnetron tube which operates in normal output power. According to the simulation results, it is clearly that the cathode of magnetron is bombed by low energy electrons mostly among 0 and 2keV. Based on the fact that most of the back bombardment electron belong to low energy electron, when the energy of incident electron is among 0 and 2keV, the secondary electron emission yield (SEEY) of cathodes provided with different mass percent Re doping W-Re alloy are measured, eventually, we obtain the maximum SEEY of W-Re alloy cathode when adopted by 5%Re doping.