The stability and tunability of a CARM amplifier

Theoretical analysis and computer simulations have been carried out to examine the stability and tunability of a cyclotron auto resonance maser (CARM) amplifier. It is shown that frequency tunability over one octave can be achieved by magnetic field tuning within the stability range. Tunability can be further enhanced if the waveguide wall is made lossy to increase the threshold of the absolute instability. However, beam momentum spread is found to have a strong deteriorating effect on the tunability and gain.