Increased efficiency and faster turn-on in magnetrons using the transparent cathode

The “transparent cathode” was proposed as a technique to increase the efficiency of, and reduce the start time of oscillations in a relativistic A6 magnetron. Particle-in-cell computer simulations using MAGIC were extensively performed and documented. Recently experiments were performed and output powers approaching 1 GW in S-band were measured in experiments using a short pulse (9 ns) electron beam. These results were in excellent agreement with MAGIC simulations. More recent MAGIC simulation results on an A6 magnetron using axial extraction (diffraction output) and a transparent cathode demonstrated 1.4 GW output power in S-band with nearly 70% conversion efficiency. This paper describes our recent results (latest trends) and discusses plans for application of the transparent cathode in commercial magnetrons.