The effect of potential beam energy on the performance of linear beam devices

The potential energy stored in a bunched electron beam is calculated using analytical and numerical methods. The ratio of stored potential energy to the total beam energy increases rapidly with the degree of bunching and with decreasing beam filling factor . is proportional to the beam perveance and independent of the beam voltage, as long as relativistic effects are neglected. In a velocity-modulated linear beam-type device, such as a klystron or a traveling-wave beam tube, stored potential beam energy affects both the bunching process and the process of dc to RE energy conversion adversely. For maximum conversion efficiency should be kept as low as possible. Several ways of reducing are discussed.