Hot cathode assembly for vacuum electron device

Abstract

The invention provides a hot cathode assembly for a vacuum electron device. The hot cathode assembly comprises a cathode, a heater unit and a supporting part, wherein the heater unit is located at thebottom of the cathode and is used for heating the cathode; the supporting part is used for supporting the cathode and the heater unit; and the heater unit is of a ring structure to enable the outer peripheral portion of the bottom of the cathode to be in direct contact with the heater unit and the central portion of the bottom of the cathode to be not in contact with the heater unit. The hot cathode assembly is provided with an annular heater heating structure, wherein the contact between the heater and the cathode is ring contact, the problem of large temperature difference between the center of the cathode the edge of the cathode is solved, the uniformity of the cathode temperature is improved, and under the premise of ensuring the uniformity of the cathode emissive current, the servicelife of the cathode is prolonged.

Description

technical field [0001] The invention relates to the field of vacuum electronic devices, in particular to a hot cathode assembly of a vacuum electronic device. Background technique [0002] Vacuum electronic devices, also known as electric vacuum devices, generally refer to electronic devices that use electrons to operate in a vacuum state. Vacuum electronic devices include electron guns. Electron guns are components that generate and shape electron beams, and usually include heaters, cathodes, focusing electrodes (or control electrodes), and anodes. The cathode is the source of electrons required for device interaction. At present, the cathodes used in most vacuum electronic devices are hot cathodes. The hot cathode needs to reach a certain working temperature when it is working, so that the electrons can obtain enough kinetic energy to overcome the surface barrier and escape from the surface of the cathode into the vacuum to obtain the emission current required by the devi...

AI Technical Summary

Problems solved by technology

Although this improves the heat transfer efficiency between the heater and the cathode, the temperature difference between the central part and the edge of the cathode is relatively large during use

At this time, if the emission current density at the center of the cathode is moderate, the edge emission will be insufficient; if the emission current at the edge of the cathode is moderate, "overcurrent" and high temperature will appear in the center, resulting in shortened cathode life

Therefore, the disc-shaped melting hot sub heating structure cannot better deal with the contradiction between the cathode emission current density and the cathode life.

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