Direct observations of single sonoluminescence pulses

Previous reports have described experimental measurements and theoretical descriptions of sonoluminescence without clearly resolving the physical events that underlie this phenomenon. Although incomplete, these results have led to suggestions that sonoluminescence might be such an extreme process that it could serve as an unusual inertial confinement source of fusion neutrons. Such a possibility depends on physical details of individual sonoluminescence events such as the source temperature, diameter, and density. The present report describes attempts to measure the diameter and duration of single sonoluminescence flashes. In both cases the results were limited by the resolution of the instruments, giving diameters of the order of 3 μm or less and durations of the order of 12 ps, or less. (orig.)