Micrometer-scale electrical breakdown in high-density fluids with large density fluctuations: Numerical model and...

Area of Science:

• Plasma Physics
• Fluid Dynamics
• Electrical Engineering

Background:

• Classical theories for electrical breakdown are insufficient for high-pressure gases and supercritical fluids.
• The mechanisms behind electrical breakdown in high-density fluids remain poorly understood.
• Observed breakdown voltages deviate significantly from low-pressure gas discharge predictions.

Purpose of the Study:

• To develop a novel electrical breakdown model for high-density fluids.
• To incorporate the effects of density fluctuations and ion-enhanced field emission (IEFE) into the model.
• To explain the critical anomaly in breakdown voltage near the critical point.

Main Methods:

• Developed a new electrical breakdown model for high-density fluids.
• Integrated density fluctuations and ion-enhanced field emission (IEFE) into the model.
• Utilized a modified Paschen's curve incorporating IEFE effects on the second Townsend coefficient.

Main Results:

• The model accurately reproduces experimentally observed electrical breakdown voltages (U(B)) in high-density fluids, including near the critical point.
• The study identified density fluctuations as a cause for a critical anomaly in U(B) due to locally low-density domains.
• The model suggests that the critical anomaly in U(B) is dependent on the gap distance.

Conclusions:

• Both density fluctuations and ion-enhanced field emission (IEFE) are crucial for understanding electrical breakdown in high-density, density-fluctuating fluids.
• The developed model provides a more accurate framework for predicting breakdown voltages in these complex media.
• Further research should consider these factors for advancements in plasma applications involving high-density fluids.