Two Mechanisms in a Relativistic Electron Cyclotron Maser with aSpecial Quasioptical Cavity

In a relativistic electron cyclotron maser with an axisymmetrical quasioptical cavity of oblique rotation at arbitrary angle, the rotating angle has a great influence on beam-wave interaction. Two different physical mechanisms are found with the rotating angle ranging from 0° to 90°. One is cyclotron auto-resonance maser regime for small angle, with small optimized external magnetic field; the other is electron cyclotron resonance maser regime for large angle, with comparatively large optimized magnetic field.