Pulsed Mie Scattering Measurements of the Collapse of a Sonoluminescing Bubble

Measurements of light scattered off a bubble that is illuminated by a train of short pulses enables one to resolve the strongly supersonic collapse of a sonoluminescing bubble. We find that the collapse is faster than Mach 4 (relative to the ambient speed of sound of the gas in the bubble) and that the flash of sonoluminescence is emitted within 500 ps of the minimum bubble radius, at about which time the bubble's acceleration is greater than ${10}^{11}\mathrm{g}$.