Jitter and recovery rate of a 50 kV, 100 Hz triggered spark gap with high pressure gas mixtures

Summary form only given.Recent attention to impulse antenna phased array has necessitated the need to develop a reliable high voltage, high repetition rate switch that will operate with ultra low jitter. An ideal jitter of a small fraction of the rise time is required to accurately synchronize the array to steer and preserve the rise time of the radiated pulse. This paper presents the impact gases and gas mixtures have on switch performance which includes recovery rate and in particular, jitter. A 50 Omega, 1 nF pulse forming line is charged to 50 kV and provides the low inductance voltage source. Triggering is provided by an SOS voltage source that supplies >100 kV, 10 ns rise-time pulses at a rep rate up to 1 kHz in burst mode. A hermetically sealed spark gap with a Kel-F lining is used to house the switch and high pressure gas. The system includes a gas mixing chamber that can mix various gases up to 2000 psi. Gases tested include dry air, H₂, N², and SF₆. Initial testing with 30 kV, 10 Hz switch operations have shown reliable sub-ns jitter times with pure gases including dry air, H₂, N₂, and with H₂-N₂, and N₂-SF₆ gas mixtures. The system was then modified for 50 kV, 100 Hz operations with no recovery issues. Jitter data for pure gases, H₂-N₂, N₂-SF₆, and various Kr⁸⁵ gas mixtures at the 50 kV, 100 Hz operation is also documented and compared in this paper.