Microsecond Electrical Breakdown in Water: Advances Using Emission Analysis and Cavitation Bubble Theory.

Area of Science:

• Physics
• Chemistry
• Engineering

Background:

• Electrical discharges in water are complex phenomena with diverse applications.
• Understanding the propagation and breakdown phases is crucial for harnessing these discharges.

Purpose of the Study:

• To provide deeper insights into the processes of microsecond electrical discharges in water.
• To analyze the propagation and breakdown phases of underwater electrical discharges.

Main Methods:

• Fast imaging and spatially resolved optical emission spectroscopy were used to monitor excited species (H, O, OH) during discharge propagation.
• The Rayleigh-Plesset model was employed to simulate bubble radius evolution and estimate cavitation bubble pressure post-discharge breakdown.

Main Results:

• Excited species H, O, and OH were detected throughout the interelectrode gap during discharge propagation.
• Estimated initial pressures for the cavitation bubble were approximately 1.7 × 10^7 Pa (cathode regime) and 1.2 × 10^8 Pa (anode regime).

Conclusions:

• A multidisciplinary approach combining optical emission spectroscopy and thermodynamic modeling offers a more accurate physical and chemical description of electrical discharges in water.
• This research advances the understanding of pin-to-pin electrical discharges in water, paving the way for improved applications.