Microwave components for 30 GHz high-power gyroklystron

A 30 GHz high-power gyroklystron is under construction now in IAP (Russia). In the first experiments, carried out at a single pulse regime, RF power 6.5 MW, power gain 30 dB, pulse duration 0.5 mcs, and efficiency 25% were achieved. Next experiments with a new cryogenic magnet and a new electron gun are planned at the second half of 2007 and must demonstrate a repetition rate regime. The gyroklystron has classical three-cavity (TE₅₂/TE₅₂/TE₅₃) scheme and requires a lot of external quasi-optical components: input and output mode converters, a window, and others. It is planned to feed the gyroklystron, using 10 kW magnetron, by means of TE₁₀ (rectangular) - TE₅₂ (circular) mode converter connected with the first cavity. The output mode converter is a straight TE₅₃- TE₀₄-TE₀₁ mode transformer with built-in beam collector based on expansion of oversized waveguide. Results of calculations and low power tests of all gyroklystron's components are reported.