Study of the synchrotron maser absolute instabilities

In the limits of the model used in this work (tenuous beam, infinite geometry along the Bo direction), we have shown that the synchrotron maser working as an amplifier is subject to absolute instabilities. This instability for a given mode/synchrotron harmonic interaction occurs when the synchrotron harmonic frequency exceeds the cut-off frequency of the mode. In order to prevent such instability. one has to limit the value of the magnetic field. Respecting this condition does not prevent others mode/harmonic interactions to be Subject to absolute instabilities