Experimental Research on a Split-Cathode-Fed Magnetron Driven by Long High-Voltage Pulses

In earlier research [Phys. Plasmas 27, 103102 (2020)], a split cathode was proposed to avoid pulse shortening of microwave generation in relativistic S-band magnetrons. Experiments confirmed the generation of microwave pulses limited only by the power generator's pulselength ( \sim 200 ns) [J. Appl. Phys. 131, 023301 (2022)]. In the current research, the results of experiments with the same magnetron but powered by a generator producing up to \sim 500 -ns-long high-voltage pulses are presented. It is shown that the power and duration of the microwaves depend strongly on the applied magnetic field, anode-cathode gap length, and the applied voltage amplitude. In the experiments, \sim 400 -ns, \sim 100 -MW microwave pulses were measured. It was also identified that impedance matching between the relativistic magnetron (RM) load and the high-voltage (HV) pulse generator is an important factor in the operation of these devices.