Uniform propagation of positive ionization waves over liquid water under high voltage rise rates
Year: 2026
Type: article
Abstract: The uniform propagation of a positive polarity surface ionization wave is achieved over liquid water, at atmospheric pressure, using nanosecond pulses with high voltage rise rates (+15 kV ns −1 ). The ring-shaped discharge propagation occurs over cm-sized surfaces and for a wide range of water conductivities (5–900 µ S cm −1 ), without any branching during the discharge propagation. To our knowledge, this is the first experimental evidence of a ringed-shape ionization wave, without any branching, over a cathode water surface. They are generated in a pin-to-water configuration with a sub-millimetre gap between the pin and the water surface. Using two pulse generators, the influence of voltage rise rate on the discharge propagation dynamics is highlighted. Fast imaging and electrical diagnostics are performed under moderate (+2 kV ns −1 ) and high (+15 kV ns −1 ) voltage rise rates. In the former case, the discharge develops in three stages already reported in the literature: 1/ discharge inception in the pin-water gap, 2/ propagation of a circular ionization wave over the water surface and 3/ splitting of the ionization wave front into multiple surface streamers. In the latter case, in contrast, the circular ionization wave does not branch and the discharge continues to propagate as a uniform ring until the voltage drops. This uniform propagation is preserved over a large range of water conductivities (5–900 µ S cm −1 ). However, the conductivity slightly influences the propagation length, speed, and energy deposition. The current findings demonstrate that the use of high-voltage nanosecond pulses with sharp rise rates prevents the development of instabilities in large-scale positive polarity discharges.
Institutions: Centre National de la Recherche Scientifique, Université Paris-Saclay, CentraleSupélec, Laboratoire d'Énergétique Moléculaire et Macroscopique, Combustion, Laboratoire de Physique des Gaz et des Plasmas, Université Sorbonne Paris Nord, Laboratoire des Sciences des Procédés et des Matériaux
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,325
OpenAlex ID: W7170164317