Optimization of a Sheet Electron Beam Interaction With a Slow Wave

A simple planar circuit model consisting of impedance and screen electrodes is used to analyze the strength of the interaction of a sheet electron beam with the in-phase slow-wave mode of the circuit. The impedance approximation is used to represent the fields of E- and H-waves by the zero and ±1 space harmonics. A new generalized formula for the coupling coefficient characterizing the interaction strength is used to demonstrate its dependence on the thickness of the sheet beam and the distance between the impedance and screen electrodes. A comparison between the coupling coefficients calculated for sheet and cylindrical beams shows the significant advantage of the sheet beam configuration.