Measurement of a sonoluminescence bubble's dynamic behavior by Mie scattering

The steady single-bubble sonoluminescence (SBSL) under the proper conditions of resonance frequencies △f/f₀(~10^-4, f₀=21 kHz) and sound pressure P_a (1.2 atm~1.5 atm) at room temperature was successfully obtained. The sound pressure P_a-dependent dynamic behaviors of the bubble, including its radius versus time curve R(t), ambient radius R₀, and the compression radio R_max/R₀, were investigated by fitting the Mie scattering measurement data to Rayleigh-Plesset equation. Meanwhile the energy dissipation of the bubble through rebound by calculating its potential energy was estimated. It is found that R_max/R₀ increased with P_a, while the ratio of bubble's rebound energy to its total energy decreased (10^-1~10^-3), which indicated that most energy of the bubble was transformed into thermal energy and/or generating the imploding shock wave.