A vacuum-sealed repetitively pulsed high-power microwave system

For the recent decades since born, high-power microwave technology has experienced a development process from the simple pursuit of maximum output peak power to the pursuit of lightweight, miniaturization, modularity and practicality. The necessary condition for the high-power microwave system to operate normally is maintaining vacuum in the generation, transmission and transmitting cavity of the high-power microwave. Traditionally, bulky external vacuum pumps are used to obtain and maintain vacuum, which increase the size and weight of the system, limiting its practical application scenarios. In this paper, a vacuum-sealed X-band repetitively pulsed high-power microwave system is designed, which is realized by brazing large-sized ceramic and metal. Using traditional methods of vacuum acquisition in the field of vacuum electronics, such as material surface cleaning and baking, the system can maintain pressure of the order of $10^{-7} \mathrm{~Pa}$ for close to 100 hours in non-operating conditions. The non-evaporable getter (NEG) pumps are installed on the cylinder of diode and the feed horn using the knife-edge flange, which can effectively capture the gas released in the cavity when the system is powered up and maintain vacuum dynamically. The pressure changes of the cathode and the feed horn area inside the cavity when the system emits electron beams are simulated using COMSOL, which are in good agreement with the experimental data. The experimental results show that the system can run more than 10,000 shots stably at the pulse repetition frequency of $10 \sim 30 \mathrm{~Hz}$.