Accelerated test and life evaluation method of microwave tube in short vacuum tube

Microwave tubes for communication must have high reliability, high power, and a long life of 10 to 15 years. Cathode as the electric source module in microwave vacuum tubes, its reliability and life directly affect the tube´s reliability and life. In this paper, electronic gun in short tubes are accelerated to evaluate the lifetime of one kind of microwave vacuum (such as traveling wave tube). In order to shorten the testing process, accelerated life-test tests method is established at higher operating temperature and currents of cathode. The highest acceleration is obtained at the cathode temperature of 1100 °Cb with the cathode current density of 1.5A/cm². One of the most common equations used to analyze cathode lifetimes is the Arrhenius model. Lifetimes were estimated based the time at which 50% cumulative failures had occurred using OriginPro75 software.