XXXV. Comments on Magnetron Theory, with Particular Reference to Some Recent Publications

Abstract

ABSTRACT The wartime development of magnetron theory is outlined, beginning with non-existence proofs for double stream steady states, the vindication of the single stream steady state by transient calculations and the recognition that cylindrical symmetry must be abandoned for further progress. The success of work with transverse fields is recalled, giving agreement with experiments in the form of acceptable self-consistent orbits and fields. the threshold criterion and the natural instability of the single stream steady state to travelling wave perturbations, explaining start-up, high noise and high diode currents after ‘cut-off’. Recent publications, all unduly preoccupied with symmetrical steady states, are then discussed, in particular the first three papers of this Journal's first issue. Their writers, perhaps unaware of some of the wartime work because of its inaccessibility, draw conclusions which are at variance with the picture developed during the war. However, closer examination shows that the...