Storage film-coating dipped barium-tungsten cathode and preparation method

Abstract

The invention discloses a storage film-coating dipped barium-tungsten cathode and relates to an electron device technology. The cathode adopts the following chamber tungsten sponge matrix structure: the cathode is divided into both inner and outer tungsten sponge matrixes; the inner end face of the inner tungsten sponge matrix is fixedly connected with a partition; the rest faces of the inner tungsten sponge matrix are coated with the outer tungsten sponge matrix; the lateral surface of the outer tungsten sponge matrix is fixedly connected with the inner wall of another accommodating cavity; the inner tungsten sponge matrix has porosity of 40 percent to 45 percent; the outer tungsten sponge matrix has porosity of 20 percent to 22 percent; and the outer end face of the outer tungsten sponge matrix is coated with a 0s-Ir-Al film. The cathode disclosed by the invention has the characteristics of large emission current density, long service life and the like; and a DC (Direct Current) emission volt-ampere characteristic curve result shows that when the working temperature of the cathode is 950 DEG C, a current of a deviated point can reach 5A / cm<2>. According to the invention, the emission current density of the barium-tungsten cathode is improved; storage of active materials is improved; the service life of the cathode is prolonged to 12 to 15 years; and the development requirement of a space travelling wave tube on the long service life of the hot cathode is met.

Description

technical field [0001] The invention relates to the field of electric vacuum technology, in particular to a storage-type film-impregnated barium-tungsten cathode using a small chamber tungsten sponge matrix structure and a preparation method, thereby increasing the emission current density of the barium-tungsten cathode, increasing the storage of active materials, and prolonging the life of the cathode. Background technique [0002] With the development of vacuum microwave devices, especially military microwave devices, the life of the cathode is required to be greater than 10 years. For the long-life cathode, the following requirements should be met: (1) the working temperature is low, which reduces the evaporation of the active material and reduces the burden on the heat; (2) the work function is small, so that it can be provided at a lower working temperature The required emission current; (3) Sufficient storage of active substances to ensure continuous replenishment of t...

AI Technical Summary

Problems solved by technology

The traditional film-impregnated barium-tungsten cathode, that is, the M-type cathode, can no longer meet the above requirements.

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