Sa. Naqvi et al., RESONANCE SHIFT IN RELATIVISTIC TRAVELING-WAVE AMPLIFIERS, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 53(4), 1996, pp. 4229-4231
We examine analytically the linear operation of relativistic traveling
wave tube amplifiers. In this regime it is found that the maximum gro
wth rate occurs at a beam velocity below that expected on the basis of
resonance with the cold dispersion relation of the slow wave structur
e. The maximum growth rate can be much larger than that at the resonan
ce condition. These results have significance when extending Pierce's
theory to traveling wave amplifiers driven by relativistic electron be
ams.