The dynamics of streamer discharges at the plasma-water interface

Plasma-liquid interactions represent one of the current and complex research areas in modern science. A deeper understanding of these interaction mechanisms can provide a foundation for developing innovative technologies in medicine, environmental science, agriculture, and materials science.

Recent studies have investigated the interaction mechanisms between water and plasma in various configurations, identifying factors influencing the dynamics of these interactions. However, a comprehensive understanding of this field is still developing, and many previous works have focused on plasma jets impacting water. In contrast, the novelty of our study lies in the direct discharge applied to the water surface, examining the discharge propagation and surface deformation mechanisms at the plasma-water interface without the presence of a plasma jet.

The study was conducted using an experimental setup consisting of an electrode system, with distilled water employed as the working medium. At low voltages, individual streamer channels form at the air-water interface between the electrodes. As the voltage increases, these channels branch and become more complex in space. A further increase in current accompanied by a decrease in voltage leads to the onset of a continuous discharge phase. During the investigation, the behavior and transition mechanisms of these discharges at different voltage levels were analyzed, as well as the development stages of the streamer channels. The processes involved in plasma-water interaction were explained by calculating the force balance at the plasma-water interface.

These studies provide both qualitative and quantitative insight into the physical phenomena occurring at the plasma-water interface and their underlying interaction mechanisms.