Using traveling wave structures to extract power from relativistic klystrons.

摘要

The purpose of this note is to analyze the excitation of traveling wave (TW) output structures by an RF current. Such structures are being used in relativistic klystron experiments at Lawrence Livermore National Laboratory. First we will preset a set of difference equations that describes the excitation of the cells of a TW structure. Next we will restrict our attention to structures that have identical cells, except possibly for the first and last cells. Under these circumstances one can obtain difference equations that have constant coefficients, and we will present the general solution of these equations. Lastly we will apply our results to the analysis of a TW output structure. We will show that, by appropriate choice of the quality factors (Qs) and eigenfrequencies of the first and last cells, it is possible to obtain a traveling wave solution for which there is no reflected wave and where the excitation grows linearly with cell number.