In this work, evolution of parameters of nanosecond repetitively pulsed (NRP) discharges in pin-to-pin configuration in air was studied during the transient stage of initial 20 discharge pulses. Gas and plasma parameters in the discharge gap were measured using coherent microwave scattering, optical emission spectroscopy, and laser Rayleigh scattering for NRP discharges at repetition frequencies of 1, 10, and 100 kHz. Memory effects (when perturbations induced by the previous discharge pulse would not decay fully until the subsequent pulse) were detected for the repetition frequencies of 10 and 100 kHz. For 10 kHz NRP discharge, the discharge parameters experienced significant change after the first pulse and continued to substantially fluctuate between subsequent pulses due to rapid evolution of gas density and temperature during the 100 μs inter-pulse time caused by intense redistribution of the flow field in the gap on that time scale. For 100 kHz NRP discharge, the discharge pulse parameters reached a new steady-state at about five pulses after initiation. This new steady-state was associated with well-reproducible parameters between the discharge pulses and substantial reduction in breakdown voltage, discharge pulse energy, and electron number density in comparison to the first discharge pulse. For repetition frequencies 1–100 kHz considered in this work, the memory effects can be likely attributed to the reduction in gas number density and increase in the gas temperature that cannot fully recover to ambient conditions before subsequent discharge pulses.
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Development of a substrate-invariant 2-D array of nanosecond-pulsed streamer discharges
Two dimensional arrays of streamer discharges were developed using electrical discharge machining of stainless steel sheets and stacking them together with spacers to allow gas flow between the sheets. A nanosecond pulsing circuit, capable of delivering 2–40 kV pulses with pulse widths of >20 ns by using two spark gaps as switches, was developed as a simple tunable pulsing power supply. High resolution imaging of the plasma for uniformity across the array tips was conducted. Optical emission spectroscopy was used to characterize the species created as well as probe the temperature of the discharge for various substrates, voltage pulse durations, voltage pulse magnitudes, and gas flows. The discharge properties were found to be substrate independent for a wide variety of conditions.
more » « less- NSF-PAR ID:
- 10303259
- Publisher / Repository:
- IOP Publishing
- Date Published:
- Journal Name:
- Plasma Research Express
- Volume:
- 2
- Issue:
- 1
- ISSN:
- 2516-1067
- Page Range / eLocation ID:
- Article No. 015001
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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