Sean M. Cordry
York College, York, NE 68467
Lawrence A. Crum
Ronald A. Roy
Appl. Phys. Lab., Seattle, WA 98105
Bubbles acoustically levitated in the appropriate underwater sound field can undergo radial motion which causes the bubbles to be luminescent, a phenomenon known as single-bubble sonoluminescence (SBSL). It has been reported [Hiller et al., Phys. Rev. Lett. 69, 1182 (1992)] that cooling the temperature of the water by 20[sup o]C can increase light emission by a factor of 12.5. In this present study, the acoustic energy radiated by SBSL was measured using a needle hydrophone and the number of photons emitted by the bubble was measured with a photomultiplier tube. Comparisons were made between the acoustic and electromagnetic radiation emitted by the bubble for a range of different temperatures and acoustic pressures. Although the number of photons emitted varied strongly with the temperature, the radiated acoustic energy did not. These results suggest that it is the internal gas dynamics and not the bubble dynamics which is responsible for the observed temperature-related effects. [Work supported by the Office of Naval Research.]