Method for producing nano graphite field emission vacuum electronic cathode

Abstract

The invention belongs to the field of vacuum electronic element and device production and a method for producing field emission microwave vacuum electronic cathode by using a nano graphite material. The method comprises: processing industrial expanded graphite sheets at high temperature to produce wormlike expanded graphite; processing the wormlike expanded graphite with solution of concentrated sulfuric acid and potassium permanganate to produce nano graphite sheets; washing the nano graphite sheets to remove acid and purifying the nano graphite sheets by using ultrasonic waves and centrifugation; filtering and drying the nano graphite sheets and forming a film; rolling up the film to produce a nano graphite cylinder; and subjecting the nano graphite column to calcining and post treatment to obtain the nano graphite cylindrical cathode. The method has the characteristics that: the production process is simple, reliable, low in energy consumption and high in production efficiency; the produced electronic cathode has a small cross section and high stability, can emit high-intensity current in use, makes the industrial production realized easily; and the like. The method overcome the drawbacks of the prior art such as difficult use in field emission microwave tubes, digital tubes, projection tubes and other tube vacuum electronic elements, complicated production process, low production efficiency, high production cost and the like.

Description

technical field [0001] The invention belongs to the field of vacuum electronic components and device production, in particular to a production method of a field emission microwave vacuum electron cathode produced by nano-graphite materials. , Nixie tubes, projection tubes and other tube-type vacuum electronic devices for the cathode. Background technique [0002] The cathode of traditional microwave vacuum electronic devices is generally made of tungsten oxide or tungsten related materials, which belongs to hot cathode emission; the electron emission cathode used in traditional projection tube electronic devices also relies on thermionic emission, so the existence efficiency is low and the working temperature is low. High and preheating, as well as large volume, high power consumption and other defects; for these defects and the use of nano-graphite as a field emission cathode technology is the use of chemical vapor deposition growth, or the method of making a film after dis...

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Problems solved by technology

[0002] The cathode of traditional microwave vacuum electronic devices is generally made of tungsten oxide or tungsten related materials, which belongs to hot cathode emission; the electron emission cathode used in traditional projection tube electronic devices also relies on thermionic emission, so the existence efficiency is low and the working temperature is low. High and preheating, as well as large volume, high power consumption and other defects; for these defects and the use of nano-graphite as a field emission cathode technology is the use of chemical vapor deposition growth, or the method of making a film after dispersion with a solvent to obtain nano Graphite film, and then made into a planar film-shaped field emission electron cathode, that is, a cathode that emits electrons through the graphite film plane; although this type of electron cathode has the advantages of high emission efficiency and high current density, it is generally only used in cold In terms of cathode field emission flat panel display, it is difficult to be used in tube-type vacuum electronic devices such as field emission microwave tubes, digital tubes, and projection tubes, and there are disadvantages such as complex production processes, low production efficiency, and high production costs.

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