An examination of the performance of backward wave CFA´s and magnetron´s in simulation and experiment

Summary form only given. MRC will present comparisons of 3-D simulations of amplitrons (backward wave CFAs) under cold test (no electrons present) with experimental cold tests. These will include measurements using both methods of S11 and S22 parameters vs. frequency. Results both for a the so-called, "baby" amplitron, an S-band tube currently used by the US Navy, and a new, experimental, ultra-high-average-power, UHF amplitron will be presented. The baby is of interest in that it exhibits spurious output, ostensibly due to resonant phenomena caused by impedance mismatches within the tube. In order to study this in detail, MRC is performing both computer and experimental cold tests of each major section of these tubes, which includes double a ridged waveguide taper and a two-conductor TEM transmission line on both the input and the output, and the amplitron slow-wave circuit itself. Related work which we plan to report includes MACIC hot runs on both tubes, attempting to verify performance results against experimental runs and to study spurious behavior, and MACIC studies of multipactor.