An Experimental Study of Low-Power CW Magnetrons Having Few Segments

It is shown that, apart from having intrinsically lower efficiency, two- and four-segment magnetrons differ very little in characteristics from multisegment types if the ratio of cathode-to-anode diameter is the same in each case. High efficiency, comparable under some conditions to that of multisegment magnetrons, can be obtained from tubes having few segments when the cathode is relatively much smaller. This results in a number of observable differences between the behavior of the two types, notably a variation of efficiency with diameter in two- and four-segment tubes, which is accompanied by nonconformity to the voltage scaling laws.