AC electric discharge in a $1\%$ sodium chloride solution in distilled water at low pressures

The results of an experimental study of an alternating current discharge with a frequency of $50$ Hz in a gas-liquid medium of a $1\%$ of $\rm NaCl$ solution in distilled water with air bubbles and microdischarges inside a dielectric tube with a diameter of $10$ mm at reduced pressures for various interelectrode distances of copper electrodes—$50{,}~100$, and $150$ mm—are presented. A qualitative mechanism for the development of a breakdown and discharge at low pressures in a gas-liquid medium is established. It is found that with a decrease in pressure, a gas-liquid medium is formed, saturated with small air bubbles ranging in size from $1$ to $3$ mm as a result of boiling and electrolysis. This, in turn, leads to a breakdown and rapid discharge ignition in a porous medium near a solid electrode. The transition of an electric discharge with microdischarges to a volumetric discharge at low pressures is established. A fast Fourier transform was carried out, and the discharge voltage and current spectra were determined at reduced pressures.