Observation of Stability Boundaries in the Parameter Space of Single Bubble Sonoluminescence

The region of parameter space (acoustic pressure $P_a$, bubble radius $R_0$) in which stable single bubble sonoluminescence (SBSL) occurs in an air-water system is a small fraction of that which is accessible. This is due to the existence of an island of dissolution at high $P_a$ and small $R_0$. For dissolved gas concentrations above 50% of saturation, the region lies above the threshold for shape oscillations and is unobservable. Below 50%, an oscillating bubble is stabilized on the boundary of the island which lies below the shape threshold. SBSL is shown to exist exclusively along this boundary.