Operation of an X-band dielectric Cherenkov maser amplifier

Summary form only given. The performance of a dielectric Cerenkov maser operating as an amplifier was studied theoretically and experimentally. The amplifier is designed to work in the TM₀₁ mode of a cylindrical, dielectric-lined waveguide. Two different sets of experiments were carried out on two separate electron-beam-generating systems. In a low-voltage. low-current (200-kV, 100-A) experiment, results indicate that the device operated as an amplifier at frequencies between 9.7 and 10 GHz. The RF input was provided by a tunable (9-10-GHz), 10-kW magnetron. An average power gain of ~0.6 dB/cm over a 21-cm interaction length was measured. The RF pulse length was ~1 μs. In a scale-up of the experiment to a system driven by a 700-kV to 1-MV, 3-kA. 100-ns electron beam with RF input provided by a tunable (8.4-9.6-GHz), 200-kW magnetron, preliminary results indicate a power output of 280 MW at 8.6 GHz with a peak power conversion efficiency of ~11%. Particle-in-cell simulations using the code ISIS confirm the potential for high-efficiency operation of the amplifier