CYCLOTRON MASER OSCILLATOR EXPERIMENTS IN A PERIODICALLY LOADED WAVE-GUIDE

The periodic-waveguide cyclotron maser is a device in which orbiting, nonrelativistic electrons interact with traveling waves in a metallic, periodically loaded waveguide, In this paper, we describe a table-top oscillator experiment that operates in the microwave regime (9.4 GHz) with a low-energy (8 keV), low-current (0.2 A) electron beam pulse (1 ms pulse width), The frequency modulation (chirping) observed is used in the determination of cyclotron resonance condition for this intera ction, The results show that the cyclotron interaction occurs with a b ackward-propagating wave in the periodically loaded waveguide. Microwa ve power of greater than or equal to 0.3 kW and efficiency of greater than or equal to 20% are measured by an external loading of the oscill ator,