Some studies on a high-perveance hollow-beam klystron

The performance of an experimental high-perveance hollow-beam klystron has been investigated. Data of small- and large-signal operation are presented in this paper. For strong magnetic confinement of the beam, it is shown that gap interaction and gain and large-signal bunching are well predictable by the appropriate theories. A sensitivity of all measurable RF-quantities to the level of the focusing field has been studied. Efficiencies are lower than predicted from the measured high degree of bunching, and reflect the effect of potential depression.