Simulation Studies of a Klystronlike Amplifier Operating in the 10-100 GW Regime

摘要

A coaxial drift tube allows propagation of an ultra high power relativisticelectron beam (500 keV, > or = 100 kA, 100 ns). This paper covers the modulation of a large diameter (12.6 cm) intense relativistic electron beam (500 keV, 16 ka) by an external microwave source via particle simulation. The annular beam, enclosed within a coaxial drift tube, is found to be fully modulated by a low-power external rf source at a frequency of 1.3 GHz. For such an intense beam, a highly nonlinear interaction takes place at the modulating gap, producing highly coherent bunches of electrons. This finding is similar to earlier research in which such modulation was studied for an intense beam propagating in a hollow drift tube. Unlike the hollow drift tube case, the coaxial configuration is easily scaled to high power. Here, a very large diameter (26 cm) intense beam (460 keV, 100 kA) is fully modulated at 1.3 GHz to obtain 31 GW of rf beam power. Keywords: High power microwaves, Intense beam modulation, Relativistic klystron amplifiers.