Mie scattering from a sonoluminescing bubble with high spatial and temporal resolution

Abstract

The dynamics of a single-air bubble trapped in a resonant sound field in water has been characterized by Mie scattering and a Streak camera with high spatial and temporal resolution. The streak images show that in the endphase of the cavitation collapse the scattered light intensity is no function of the bubble radius anymore. In the last nanoseconds around minimum bubble radius most of the light is scattered at the highly compressed water surrounding the bubble and not at the bubble wall. This leads to a minimum in the scattered light intensity about 700 ps before the sonoluminescence pulse is emitted. And neglecting this changes leads to a strong overestimation of the bubble-wall velocity. In the reexpansion phase the high spatial resolution of the streak camera allows one to distinguish between the light scattered at the bubble wall and the light scattered at the outgoing shock wave.