High Voltage, Low Inductance Hydrogen Thyratron Study Program.

Abstract : This report documents the results of a twelve-month study program directed toward gaining the information necessary to fabricate a high voltage, low inductance hydrogen thyratron switch capable of operating with a peak forward anode voltage of 250kV, a peak forward anode current of 20 to 40 kA for 60 ns, and a current risetime of 10 to 20 ns. Operation under these conditions is ultimately required at high pulse repetition rates. The principal conclusion is that thyratron operation at 250 kV and 40 kA with a current risetime of a few tens of nanoseconds is a feasible proposition. However, the development of a tube having such capabilities is subject to the practical limits that are imposed by the breakdown characteristics of the ceramic insulators that are universally used in the construction of high power tubes. Operation at appreciable repetition rates is clearly subject to the ability of the tube to withstand the heating that results from operation at high average current and high di/dt. During the first phase of a multi-phase program, the emphasis of the work was placed on those factors that affect the voltage-inductance compromise, since it was determined that the tube's inductance (and not its commutation time) would dominate the maximum achievable di/dt.