Thermal Analysis And Optimizad Design Of Tmt's Cathode Module

With the characteristics of wide band, wide pulse, long life and high reliability, TWT is the key device in electronic communication systems, radar, electron counter measurement, ground workstation and microwave heating. It takes the important function in modern high-tech battle. Thermal character is one of TWT's very important guide-line in all kinds of its characters, which is not only the main factor to decide the average power output, but also directly affects TWT's work stability and reliability. With the development of manufacture technology, its thermal reliability problem has attracted more and more people's attention.Among the factors affecting TWT's reliability and thermal performance, cathode module is the easiest part to fail, and then becomes the main source providing TWT's reliability guarantee. The thermal distributing,thermal dissipation inside electron gun has attracted the attention of production units, for example the thermal dissipation greatly delay the warm-up time of cathode. According to the requirements from TWT industry in China, this paper focus on analyzing the thermal status and optimal design of cathode module in order to built up the background for reliability design of TWT in China.Thermal dissipation of cathode module is simulated and analyzed with the FEM application-ANSYS in this paper, especially cathode module that is the uppermost part for thermal dissipation in electron gun. Comparing simulation results with test results and mathematic calculation, and explaining the differences by thermal contact resistance, the FEM thermal simulation technology can be proved to be correct and credible. Controlling points and methods to optimize cathode module are confirmed based on above results, and then three of optimized methods are provided for the selection. The easiest method is chosen to prepare sample for experiment about an M-type cathode. Simulating results prove that the optimized thermal cathode module can effectively shorten the warm-up time of cathode. An appropriative analysis system with VB7.0 edits environment on the WINDOWS platform has been developed, which is convenient for the TWT's designer to analyze and fabricate the TWT cathode module.Thermal FEM simulation and optimal designing platform for cathode module in electron gun of TWT has been set up. The thermal distribution chart, heat flux chart and warm-up time have been obtained so that optimize the key structure, material and technology in order to improve cathode work temperature, shorten the warm-up time of cathode under the given heat power. These results will supply the theory basis for fast warm-up cathodes, and provide theory and emulation technology basis for studying the thermal character of full TWT electron gun.