A special electron gun for electron beam bombardment furnace

Abstract

The invention discloses an electronic gun special for an electron beam bombardment furnace. The electronic gun is mainly composed of an electronic gun shell, lamp wires, a cathode, a beam-forming electrode assembly, an anode, a beam-forming electrode, a lamp wire head end electrode, a lamp wire tail end electrode, a cathode electrode, an electric reactor, an insulation assembly, insulation coolant oil and a high-voltage cable leading-out head, wherein the lamp wires, the cathode, the beam-forming electrode assembly, the anode, the beam-forming electrode, the lamp wire head end electrode, the lamp wire tail end electrode, the cathode electrode, the electric reactor, the insulation assembly, the insulation coolant oil and the high-voltage cable leading-out head are arranged in the electronic gun shell. The electric reactor which is additionally arranged is composed of an iron core and a winding wound on the iron core. The electric reactor is immersed in the insulation coolant oil. The head end of the winding of the electric reactor is connected with the beam-forming electrode, and the tail end of the winding of the electric reactor is connected with the cathode electrode. The electronic gun can restrain the transition of an electron beam, and therefore the beam passing rate of the electronic gun is improved.

Description

technical field [0001] The invention relates to the field of electron beam processing equipment, in particular to an electron gun dedicated to an electron beam bombardment furnace. Background technique [0002] The electron gun of the electron beam bombardment furnace usually adopts an axisymmetric Pierce electron gun structure, and the electron beam emitted by the cathode is restricted by the temperature-limited state and the space-charge-limited state. The saturated electron beam current density emitted by the cathode in the temperature-limited state is given by the formula decision, where i s is the saturated electron beam current density emitted by the cathode, A 0 is the Richardson constant, T is the thermodynamic temperature of the cathode, k is the Boltzmann constant, is the work function of the cathode material. In the state of space charge limitation, at a certain cathode temperature, the electron beam current density emitted by the cathode is given by the for...

AI Technical Summary

Problems solved by technology

The disadvantage of this electron gun is that the control of the electron beam current can only control its average value, and the time constant is relatively large. When the electron beam is transient, it may cause the beam flux rate of the electron gun to drop and affect the life of the electron gun.

If the cathode and beamforming electrodes are separated, the grid bias voltage E is changed b The method of changing the effective emission area of ​​the cathode to control the electron beam current can partially improve the transient beam flux rate of the electron beam, but the grid bias voltage E b Reducing the emission capability of the cathode will increase the operating temperature of the cathode, thereby reducing the life of the cathode

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