Effects of Intense Relativistic Electron Beam on the Microwave Generation in a Foilless Low-Impedance Transit-Time Oscillator

A low-impedance transit-time oscillator without foils has been proposed in our previous work. Recently, the correlated experiments have been carried out in our laboratory. In the experiments, two kinds of explosive-emission cathodes made of copper dielectric and polymer velvet were employed, and the electron collectors mainly consist of stainless steel and graphite. The experiments show that the cathode and collector materials have great influence on microwave generation in the device. This paper presents the experimental results, along with comparisons with the simulation results. It was found that the combination of the polymer-velvet cathode and the graphite collector is much more advantageous to the generation of high-power microwaves.