Electron beam coupling in interaction gaps of cylindrical symmetry

In a ballistic analysis in which space-charge effects have been neglected, the method of describing the performance of re-entrant cavity resonators in terms of beam-coupling coefficients, beam-loading conductance ratios, the shunt impedance R, and the cavity quality factor Q has been generalized and extended for the treatment of any kind of resonator with electric fields of arbitrary spatial distribution. As one consequence, the properties of resonant helix sections and cavity resonators can be directly compared in terms of the same physical concepts.