Excitation and amplification of the microwaves in a plasma filled slow wave structure

Summary form only given, as follows. Summary form only given. We present an analytical and numerical investigation of the excitation of electromagnetic waves in a plasma filled dielectric coated wave guide by an intense relativistic electron beam (/spl omega//sub b//sup 2//spl ges/c/sup 2//spl gamma/ /s, where /spl gamma/=(1-v/sup 2//c/sup 2/)/sup -1/2/ is the relativistic factor of the electron energy, /spl omega//sub b/ is the plasma frequency of the beam electrons, c is the velocity of the light and ´s´ is the cross sectional area of the beam). The beam is injected into the waveguide in the plane z = 0 (the z-axis coincides the axis of the wave guide) filled with plasma.. In the unperturbed state the densities of the beam and the plasma do not depend on z coordinate. In the transverse direction, however, their densities are not uniform. Both the beam and the plasma are cold. The static charge and current of the beam are neutralized and the slow motion of the plasma ions is disregarded. We consider the frequency spectra of the plasma waves in a specific geometry a circular metallic waveguide coated with dielectric, which contains plasma. We present our results depicting the frequency spectra of the electromagnetic and plasma waves and discuss the effect of plasma on microwave excitation.