External gate-controlled cold cathode array electron gun

Abstract

The invention discloses an external gate-controlled cold cathode array electron gun. The problems in the prior art such as poor accuracy, poor pressure resistance of devices, poor stability and complex process are solved. The external grid-controlled cold cathode array electron gun comprises a cathode base, a cathode substrate fixed to the cathode base, a cold cathode emission unit array arranged on the upper end face of the cathode substrate and having a slot, and an electron gun shell of which the upper end part is open and the lower end is connected to the cathode base and sealed. The inside of the electron gun shell is hollow. The electron gun shell is composed of a lower sleeve and an upper sleeve, a gate fixing lower base with a through hole in the middle is arranged between the lower sleeve and the upper sleeve, an external gate is mounted on the gate fixing lower base, and a gate fixing upper base is arranged on the external gate. The external gate can move up and down relative to the electron gun shell so that the distance between the external gate and the cathode substrate can be adjusted. The external gate-controlled cold cathode array electron gun of the invention has the advantages of simple manufacturing process, high precision, good consistency, and the like.

Description

technical field [0001] The invention relates to a field emission external grid-controlled cold cathode array electron gun, which belongs to the technical field of vacuum electronics and is used in vacuum electron radiation source devices or devices that generate large currents. Background technique [0002] Field electron emission is a form of electron emission that is completely different in nature from thermionic emission. Thermionic emission is to increase the temperature of the object and give additional energy to the electrons inside the object, so that some high-energy electrons can escape over the potential barrier on the surface of the object. The highest current density that thermionic emission can provide is only a few Hundred A / ㎝ 2 , and there is still a period of hysteresis; but even if the metal is heated to a high temperature where significant evaporation occurs, the number of electrons that can escape only accounts for a very small part of the total number o...

AI Technical Summary

Problems solved by technology

However, it is precisely because of the addition of a specific insulating medium that its thickness is on the order of microns, making it easy to mix metal shavings or impurities in the manufacturing process, resulting in current on the surface of the medium, causing sparking, and damaging the device. , affecting the operation of the device

At the same time, since the field emission is related to the strength of the surface electric field, the higher the electric field strength, the better in theory. Therefore, there is a very high requirement for the withstand voltage strength of the device, but the introduction of the medium in its structure greatly reduces the device's performance. withstand voltage, and cannot generate large current

[0005] Therefore, this cold cathode electron source array with embedded electrodes is not suitable for electric vacuum radiation source devices or devices requiring large currents

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