High Power On-Off Switching with Crossed Field Tubes

A crossed field tube is used as an on-off switch to produce square, 25 μs wide current pulses at 40 kV and 3.2 kA. Operation is also demonstrated at 120 Hz at an initial 50 kV and 1.3 kA for a ten pulse train. Calculations indicate that continuous operation at over 150 kW of average power is possible with a suitably designed cooling system. A crossed field tube operated in this way has a higher current capability and lower dissipation than hard vacuum tetrodes and could replace such tubes in higher power, lower impedance modulators.