Long pulse, 500 kW, wide band crossed field amplifier

This paper describes a tube designed for wide band, long pulse operation at S-band with an output peak power higher than 500 kw and an average power of 5 kw. This tube has a bandwidth of 350 MHz at 1 db, a large signal gain of 17 db, an efficiency of 50% and a signal-to-noise ratio better than 3O db. The main studies are: a water-cooled delay line structure having low dispersion and low spurious electromagnetic radiation; a gun permitting good beam injection and with moderate cathode emission density; a cathode having low barium evaporation; a sole surface having low secondary emission; and a collector having a good distribution of electron beam bombardment. Results are presented on the relationship between signal-to-noise ratio and: heater power, gain, sole secondary emission, beam impedance, and fast mode excitation.