Consistency. Cathode Hot-wire Components

Cathode is one of the core components of microwave vacuum device. Life time and reliability of a cathode have an important influence on the microwave device, which largely determine the longevity of a microwave tube. In the current cathode production, due to the human factors and constraints in the process, the cathode's consistency in batch to batch in mass production can not meet the requirements well.Coating of dispenser cathode (M type)is the research object in this article. It also has a specific analysis of the various components of the cathode's influences on the consistency of cathode, and production process of various components is also investigated. The main results are shown as the following:1,Investigate of the coated dispenser cathode structure, with 100℃decreased temperature difference between the heater and the cathode, which improve the heating efficiency and increase the reliability of heater.2, The cathode base of uniform effective porosity and mass production is obtained; and optimization of porosity of the cathode base is realized. Meanwhile, the porosity of cathode basee can be controlled in 26% to 28%.3, The ideal emission material of the tectorial membrane dispenser cathode is determined: aluminate with batch formula 2.4:0.6:1; had a research of the launch material impregnation process to ensure the consistency and uniformity of the cathode basal body impregnated emission material.4, The corrosion depth and corrosion procession parameters is determined, and so are the thickness of the layer and process parameters in coating. Developed technology achieved the merits of uniform, solid and thick consistence and process repeatability of cathode surface layer. 5, Developed heater assembly had a less than±5% heater parameters fluctuation range, and the cathode temperature fluctuation less than±2.5%.6, Study the heat treatment process and work environment of the cathode in the tube.In the 10 tested tubes, the heater voltage is 7.5V; the heater current is 1.8～1.92A; a heating power is 13.5～14.7W; the fluctuation ranges in±3.2%; the entire tube operating current between 342mA and 374mA; the fluctuation range is less than±5%.