High-power dielectric Cherenkov maser oscillator

Results are presented of experiments conducted using the dielectric Cherenkov maser (DCM) oscillator. The device consists of a cylindrical metallic waveguide with an inner radius of 3.64 cm which is partially filled with a dielectric liner. Traveling through the lined waveguide is an annular relativistic electron beam. Liners of dielectric constant epsilon =10, 5, and 2.3 were investigated for liner thicknesses of 4 and 6 mm. The 6-mm-thick, epsilon =10 liner generated an RF output of 200 MW for 20 ns at 3.8 Hz with electron-beam parameters of 700 kV, 12 kA, and pulse duration of 100 ns. The maximum measured power output for the other configurations was 80 MW at a frequency of 7 GHz ( epsilon =5), with several megawatts of power output from the polyethylene liner ( epsilon =2.3) at a frequency of approximately 9 GHz.<
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