A crossed-field multisegment depressed collector for beam-type tubes

The velocity-dependent action of crossed electric and magnetic fields can be used to sort the electrons of the spent beam of a klystron or traveling-wave tube into two or more velocity classes, and to collect each class of electrons at a potential appropriate to its velocity. Secondary electrons produced at the collection surfaces do not return to the interaction space of the tube because of the nonreciprocal action of the crossed fields. An experimental tube permitted two-segment operation with 20 per cent of the beam power dissipated in the collector at small signals. Velocity sorting that permitted operation near this percentage of beam power over a considerable range of RF signal levels was observed. The major limitation was found to be migration of secondary electrons within the collector region from low-potential to high-potential electrodes, and this process prevented the depression of the collector power below 20 per cent of the beam power.