Directly heated cathode and preparation method thereof

A direct heating and cathode technology, applied in the field of electric vacuum, to achieve the effect of increasing storage capacity, prolonging cathode life, and increasing conductivity

CN105304436AActive Publication Date: 2016-02-03INST OF ELECTRONICS CHINESE ACAD OF SCI
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2016-02-03

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Abstract

The invention discloses a directly heated cathode. A refractory oxide containing Y2O3 is adopted as an active substance; and the active substance is subjected to dip-coating on the surface of a pure tungsten filament cathode of which the surface is provided with a tungsten sponge layer to form the directly heated cathode. The invention further discloses a preparation method of the directly heated cathode. According to the directly heated cathode disclosed by the invention, the thermal emission current density of the pure tungsten filament cathode is greatly improved; and the working lifetime of the cathode is prolonged, so that the working lifetime of a high-power continuous wave magnetron is prolonged.
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Description

technical field

[0001] The invention relates to the field of electric vacuum technology, more specifically to a direct heating cathode and a preparation method thereof, the cathode adopts rare earth oxide Y 2 o 3 Compared with the pure tungsten wire cathode, the refractory oxide active material can reduce the working temperature of the cathode, increase the emission current density of the cathode, and prolong the life of the cathode. Background technique

[0002] With the development of magnetrons in the direction of high output power, ordinary oxide cathodes, barium tungsten cathodes, etc. cannot be used because they cannot withstand high voltage, are not resistant to electron ion bombardment, and are prone to electric sparks. Therefore, carbonized thoriated tungsten cathodes are used in medium power (less than 3kW) magnetrons. In the high-power continuous wave magnetron with high anode voltage (greater than 10kV), direct-heating pure tungsten (W) wire cathodes with small...

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Embodiment Construction

[0017] In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0018] The invention discloses a direct heating cathode, which adopts rare earth oxide Y 2 o 3 The refractory oxide is used as the active material, and the active material is dip-coated on the surface of the pure tungsten wire cathode whose surface is a tungsten sponge layer. The direct heating type low-temperature high-current-density cathode of the invention can work at low temperature, and the lifetime of the cathode on the life table has exceeded 3000 hours.

[0019] The invention also discloses a method for preparing a direct heating cathode, which includes the following steps:

[0020] a. After evenly spraying a tungsten powder layer on the surface of the tungsten wire substrate, put it into a high-temperature hyd...