Dancing bubble sonoluminescence in phosphoric acid solution

Abstract Sonoluminescence is more distinctly observed in phosphoric and sulfuric acid, which exhibit high viscosity and lower vapor pressures relative to water. Within an 85-wt% phosphoric acid solution saturated with argon (Ar), variations in the light-emitting regimes of bubbles were noted to correspond with increments in the driving acoustic intensity. Specifically, the bubbles were observed to perform a dance-like motion 2 cm below the multi-bubble sonoluminescence (MBSL) cluster, traversing a 25-mm 2 grid during the camera exposure period. Spectral analysis conducted at the beginning of the experiment showed a gradual attenuation of CN (B 2 Σ–X 2 Σ) emission concurrent with a strengthening of Ar (4p–4s) atom emission lines. The application of a theoretical temperature model to the spectral data revealed that the internal temperature of the bubbles escalates swiftly upon their implosion. This study is instrumental in advancing the comprehension of the underlying mechanisms of sonoluminescence and in the formulation of a dynamic model for the behavior of the bubbles.