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

Abstract

The "transparent cathode" was proposed [1] as a technique to increase the efficiency of, and reduce the start time of oscillations in a relativistic A6 magnetron [2]. Particle-in-cell computer simulations using MAGIC [3] were extensively performed and documented [1,4]. 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 [5]. 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 Sband 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.