Toward a linear theory of high current dielectric amplifiers using relativistic electron beams

An idealized model - a uniform dielectric waveguide permeated by a dense, magnetized electron beam - is examined. It is found that an increase in the beam current results in a narrowing of the amplification zone and its shift into a frequency range greater than the resonant. At the same time the Compton mode of operation of the amplifier shifts into a Raman mode or into an anomalous Doppler mechanism. The dependence of the amplification coefficient on the misalignment of the frequency at different values of the beam current is cited.