3D simulation of a realistic multistage depressed collector for high-power fusion gyrotrons
C. Wu, I. Pagonakis, S. Illy, G. Gantenbein, M. Thumm, J. Jelonnek
Proc. IEEE Int. Vacuum Electronics Conf. (IVEC), 2016, Apr, pp. 1–2
Multistage Depressed Collectors (MDCs) have been successfully applied in many kinds of vacuum tubes; however, there are only few discussions about applicable MDCs for high-power gyrotrons, regarding the hollow small-orbit electron beam and relatively strong stray magnetic field in the collector region. A novel concept has been recently proposed, where the electron beam is transformed into one or more sheet beams and sorted by the E×B drift. This contribution shows a 3D simulation result of a realistic seven-stage depressed collector model based on the above mentioned concept. With ordinary optimizations, a collector efficiency of 86 % has been achieved in this simulation.