Induced Resonance Electron Cyclotron (IREC) quasi-optical maser

This paper analyzes an induced resonance electron cyclotron (IREC) quasioptical maser configuration. This configuration has the unique features of being highly efficient and at the same time relatively insensitive to the detrimental effects of poor beam quality. A system of nonlinear coupled orbit equations, describing the dynamics of electrons in a spatially varying external magnetic field and the electromagnetic field of a steady state oscillator, are derived and analyzed. We show that with the proper choice for the index of refraction, the high frequency cyclotron interaction can be made insensitive to a beam energy spread. The interaction can, however, be sensitive to the beam's pitch angle spread. The necessary conditions on beam quality for high efficiency operation are derived and shown to be in good agreement with out numerical solutions. Furthermore, we show that by appropriately tapering the magnetic field an induced resonance condition can be achieved which results in high interaction efficiencies. It is anticipated that an efficient, high power millimeter, submillimeter and infrared radiation source can be realized with the IREC quasioptical maser configuration.