ELECTRON GUN Russian patent published in 2006 - IPC H01J3/02 

FIELD: electronic engineering; electron guns using beam-current low-voltage grid control.

SUBSTANCE: proposed electron gun that can be used for low-voltage grid control of beam current in O-type microwave devices has annular cathode with concave spherical emitting surface, radial shadow and control grids, focusing electrode electrically isolated from annular cathode and connected to control grid, as well as anode. Central part of control grid has two projections of which one faces anode and other, cathode. Projections are made in the form of hollow cylinders disposed axially with respect to gun, their outer and inner diameters being equal. Heights H₁ and H₂ of projections facing anode and cathode, respectively, outer diameter d of projections, and inner diameter D of annular cathode are chosen to comply with preset conditions.

EFFECT: reduced control voltage, enhanced electric strength and operating reliability of gun, improved thermal conditions, ability of suppressing stray thermal emission, simplified design.

1 cl, 9 dwg