Cold cathode electron source array with external grid and electronic gun formed thereby

Abstract

The invention discloses a cold cathode electron source array with an external grid, which solves the problems of poor precision, poor device pressure resistance, poor stability, complicated technology and the like of the existing technology. The cold cathode electron source array with the external grid comprises a cold cathode array fixed support (2) and a plurality of cathode emission units (3), wherein a plurality of fixing holes having the same number as the cathode emission units (3) are formed in the upper end face of the cold cathode array fixed support (2); the cathode emission units (3) are inserted and fixed into the holes in the upper end face of the cold cathode array fixed support in a one-to-one correspondence manner. The cold cathode electron source array with the external grid has the advantages of simple process, high precision, good consistency and the like, capability of improving the yield of components in processing and convenience for massive integration, and furthermore, a single cathode emission unit is independent, so that the damaged or bad cathode emission unit in an electronic gun can be replaced at any time, and thus the cost is reduced.

Description

technical field [0001] The invention relates to a cold cathode electron source array with an external field emission grid, which belongs to the technical field of vacuum electronics and is used in vacuum electron radiation source devices or devices that generate large current and high density electron beams. 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 / cm 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 s...

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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

[0006] 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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