Fields in Cavity-Excited Accelerators

Abstract

Field configuration and resonant frequency are determined for the lowest azimuthally‐independent mode of a coaxial cavity surrounding a circular tube, Several values of the width of the coupling gap are considered, and the central problem consists in determining the tangential electric fieldE t in that gap. It was found that the fields near the axis of the accelerator are quite insensitive to the actual profile of E t , and that satisfactory results are obtained by assuming E t to be constant. The problem is repeated for a parallel plane configuration, with the purpose of investigating the influence of the flattening of the cavity. Computations show that the two configurations yield fairly similar results.