The kinetic power theorem for parametric, longitudinal, electron-beam amplifiers

A power theorem is developed for parametric, longitudinal, electron-beam amplifiers which may be considered as a generalization of Chu´s well-known kinetic power theorem. The new power theorem is used to explore the limitations on noise performance of parametric electron-beam amplifiers. It is shown that the electron-beam noise does not impose a basic limit on the noise performance of a parametric electron-beam amplifier in the way a basic limit is imposed upon the noise performance of conventional longitudinal electron-beam amplifiers. The new power theorem can be employed for understanding the operation of parametric beam amplifiers in the same way as Chu´s kinetic power theorem has been used for interpreting the opoeration of longitudinal beam amplifiers.