High-speed imaging reveals the dynamics of the initiation and subsequent evolution of a nanosecond discharge propagating along the air-water interface

0580530 - ÚFP 2024 RIV US eng J - Článek v odborném periodiku
Hoffer, Petr - Prukner, Václav - Arora, Garima - Šimek, Milan
High-speed imaging reveals the dynamics of the initiation and subsequent evolution of a nanosecond discharge propagating along the air-water interface.
Plasma Sources Science & Technology. Roč. 32, č. 9 (2023), č. článku 09LT01. ISSN 0963-0252. E-ISSN 1361-6595
Institucionální podpora: RVO:61389021
Klíčová slova: fast imaging * ionization wave * plasma * streamer * water
Obor OECD: Fluids and plasma physics (including surface physics)
Impakt faktor: 3.8, rok: 2022
Způsob publikování: Open access
https://iopscience.iop.org/article/10.1088/1361-6595/acf955

A nanosecond DBD-like discharge in a coplanar electrode configuration propagating along the water-air interface is an efficient source of reactive species to produce plasma-activated water. In this letter, we report on the mechanism of the discharge onset as well as on further developments over hundreds of nanoseconds. We combined ultrafast optical imaging with electrical characteristics to capture basic morphological imprints of individual discharge phases occurring during a single discharge event with high temporal resolution. We show that during the first nanoseconds, a diffuse bi-directional ionizing avalanche expands over the liquid surface at high speed (>5 × 105 m s−1). Later, discrete plasma filaments form from the diffuse plasma due to an ionization instability. The filaments, during their subsequent elongation (∼2 × 105 m s−1), retain the diffuse plasma at both ends. The filaments re-ignite in the same positions on the liquid surface over several successive (mainly capacitive) current pulses (∼1 μs apart), which result from discontinuities in the driving voltage.
Trvalý link: https://hdl.handle.net/11104/0349294