A high-power free-electron maser for RF acceleration

Results of the design and operation of a single-mode 28 GHz free-electron maser (FEM) oscillator and a 35 GHz high-gain FEM amplifier are presented and discussed. The experiment was driven by a 700 kV, 900 Omega HV modulator, and operated with a pulse length of 1 mu s at power levels in the 1-3 MW range. To obtain the 100-500 MW, 10 ns pulses required for RF acceleration at high frequencies (K/sub a/-band), frequency chirping and subsequent pulse compression of the amplified RF signal may be used. For this type of application, phase stability is critical. The oscillator can be phase-locked to a local oscillator, yielding the required phase control of the RF.<
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