Abstract

Time-Dependence of Alcohol Quenching in SBSL

J.Guan, T.J.Matula (Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, USA)

e-mail: matula@apl.washington.edu

Previous investigations of sonoluminescence and quenching from alcohols suggest that volatile organics evaporate into the bubble interior, causing a reduction in the internal temperature, and hence a diminution in light intensity. There is, however, a question as to the evolution of the process. In one camp, it is suggested that evaporation takes place quickly and thus quenching should occur almost immediately. In the other camp, it is thought that alcohol evaporation takes place over longer times, and that the quenching occurs from a buildup of organics within the bubble over many acoustic cycles. Experimental evidence for the quenching process has been obtained by using a pressure-jump system originally designed to confirm the dissociation hypothesis for single-bubble sonoluminescence, or SBSL [T. J. Matula and L. A. Crum, Phys. Rev. Lett. 80, 865-868 (1998)]. This system incorporates both light-scattering and light-detection systems to monitor the radial motion and light emission each and every acoustic cycle. By monitoring the oscillations and light emission each acoustic cycle, we have been able to observe the time-evolution of the quenching process. Experiments were carried out for several short-chain aliphatic alcohols. The results of these experiments will be discussed.

Section : 4