Preparation And Performance Study On The Microwave Tube Barium-Tungsten Cathode

With the development of high power microwave tube, the theoretical and experiment investigation of the high performance cathode have been conducted. The research work includes how to prepare the high performance cathode and the effect of the based metal on the cathode emission, the measurement of the inner and surface fine structures of the cathode, the discussion of emission mechanism of thermionic cathode.After a lot of experiment, we finally determined the cathode preparation with an excellent emission. Undergone the powder metallurgy, the cathode possesses six features, but the ordinary cathode not. The cathodes both of the prepared tungsten-based barium-tungsten cathode and mixed metal barium-tungsten cathode have, not only high current density, but also a long life, simplified procedure and stable performance, and so on.And we made certain two good additives Cr2O3 and Ni2O3 that make the cathode performance more excellent.We made good use of the Industrial Computed Tomography(ICT),Scanning Electronic Micrograph(SEM) and Imaging analysis assemble to investigate the inner and surface fine structures of the cathode in quality and quantity. As a nondestructive technique to measure the inner fine structure of the cathode, the ICT has the uniqueadvantage.We discussed the emission mechanism of thermionic cathode, and tried to explain the excellent performance of mixed metal cathode by Richardson formula and Muller's computational model.