Gas-Insulated Self-Breakdown Spark Gaps: Aspects on Low-Scattering and Long-Lifetime Switching

Abstract

The influence of the electric field distribution between the electrodes and the seed electron generation rate on the scattering of the breakdown voltage of SF6-insulated spark gaps was investigated. The breakdown voltage scattering considerably can be reduced by applying large-gap-volume, uniform-field electrode profiles instead of spherical shaped electrodes. Moreover, uniform field electrode profiles exhibit an uniform discharge probability in the entire gap volume and following an almost uniform erosion of electrode material along the electrode's surface. This preserves electrode shape and switching performance of the spark gap for a long maintenance-free lifetime. Breakdown voltage scattering further can be reduced by increasing the seed electron generation in the gap by an auxiliary corona discharge adjacent to the main gap. The experimental observations are discussed on the basis of the volume time law for discharge initiation.

Effects of nanosecond pulsed electric field exposure on arabidopsis thaliana

“…Rectangular pulses with a pulse amplitude of 2 kV, 4 kV, 8 kV and 20 kV corresponding to a field strength of 5 kV/cm, 10 kV/cm, 20 kV/cm and 50 kV/cm were generated by a transmission line pulse generator, Figure 1. Conventional 50 Ohm coaxial cables (RG 213, Belden, VillingenSchwenningen, Germany) were charged up to 40 kV via a decoupling resistor, R D = 100 MΩ, and switched onto the output line and the treatment chamber by a corona-preionized SF 6 -insulated pressurized spark gap [41]. The pulse duration was adjusted by varying the length of the transmission line cable.…”

“…The spark gap was operated in the self breakdown mode. Due to the preionization of the gap volume by an auxiliary corona discharge, accomplished by a needle-type electrode mounted at a distance of 10 mm to the positive polarity electrode (anode) and directly connected to the anode [41], the absolute pulse to pulse deviation of the impulse voltage amplitude from the RMS-value was better than 3 %. During the experiment, the time between two pulses was 5 seconds.…”

Electroporation-based applications in biotechnology

“…Pulse generators equipped with semiconductor switches in series configuration [85] or in Marx configuration [86], low-scatter spark gap switches in self-breakdown mode [87], and spark gap switches triggered by a semiconductor-based trigger generator [88] are in use and under continuous development. For parallel configuration of Marx generators, over-voltage triggering enables long-term operation of spark gap switches without additional wear [89].…”

Inner surface flash-over of insulator of low-inductance high-voltage self-breakdown gas switch and its application

“…[1][2][3][4][5][6] The waveform of output voltage and current is determined by the pulse-forming elements and firing characteristics of the spark-gap switch for fast-rising pulses. Therefore, high-voltage and high-power switches are widely investigated by other researchers and are employed in high-power-pulse modulator for high-voltage switch.…”