Electron prebunching in microwave magnetron by electric priming using anode shape modification

Electric priming is proposed for electron prebunching in a microwave magnetron and is demonstrated using a particle-in-cell code. When the N∕2-fold perturbation of the radial electric field using an anode shape modification is imposed in the interaction space of the N-cavity magnetron along the azimuthal direction, the electrons initially develop into the desired π-mode resulting in rapid startup. The startup is hastened from 3.2 to 1.2 ns when the radial variation of the protrusion and recession is 6.5% of the anode radius with the angular width of 6°.