Investigation of the saturation properties of gyroamplifiers

The saturation properties of a TE_0n gyroamplifier are investigated using a particle-in-cell numerical code. The effect of beam velocity spread is analyzed. It is found that for velocity spread of up to 5%, the reduction in efficiency can be compensated by extending the interaction length. A numerical optimization of efficiency enhancement using a tapered magnetic field was demonstrated. A change in the saturation mechanism from phase trapping to thermalization using the suggested tapering was observed