Three-dimensional particle-in-cell calculations of an over-moded W-band gyrotron

Calculations using ICEPIC (Blahovec, JD et al., 2000) a three-dimensional, parallel, particle-in-cell code developed at the Air Force Research Laboratory, have been performed to investigate various aspects of a 100-kW class, 95 GHz gyrotron. Calculations ranging from the simplest, nearly one-dimensional calculations to explore the particle/field interaction to detailed, three-dimensional calculations based on AFRL´s l00 kW-class operating gyrotron have been performed. Calculations show the development of the TE/sub 6,2/ mode with power levels approaching l00 kW. Investigations of mode purity, sensitivity to a variety of input parameters, and the role of tube composition and geometry have been examined in ICEPIC calculations.