Image focusing method for plasma structure analysis

This study proposes an optical method for studying the structure of short-lived, non-stationary low-temperature plasmoids using the refractive properties of the plasma. We obtained possible radial distributions of the refractive index, concentration of charged particles, and temperature from the available observations of the ball lightning optical properties and the solution of the Abel integral equation. We verified the proposed method by measuring the refraction of light passing through the spherical front of a propane-air flame. The temperature fields in the flame, ball lightning, and “one-component plasmoid” were compared with digital photometry.