Few-bubble luminescence in the acoustic field of a spherical resonator in aqueous solutions of sodium and terbium compounds

Stabilization and the luminescence mode during slight motion around the equilibrium position of a few (two to eight) bubbles in 2–6 mol/L aqueous solutions of NaCl, NaOH, TbCl saturated with argon were achieved in a device for monitoring single-bubble sonoluminescence in a spherical resonator. Examples are presented of this variety of multibubble sonoluminescence illustrating various spatial-spectral distributions of cavitation bubbles, which contain either emitters comprising only the solvent continuum or also metal emitters (Na*, Tb³⁺*). Stabilization of bubbles in the form of closely (0.5–1 mm) located pairs of bubbles is of particular interest, in one of which only the solvent luminesces, and in the other, a metal.