ASA 128th Meeting - Austin, Texas - 1994 Nov 28 .. Dec 02

2pPAa4. Time scales for sonoluminescence.

Keith Weninger

Robert Hiller

Seth Putterman

Bradley P. Barber

Phys. Dept., UCLA, Los Angeles, CA 90024

The establishment of stable sonoluminescence from a single trapped bubble of air in water requires more than 5 s. During this time the bubble goes through a transition period (about 1 s long) that is characterized by an emitted intensity which is over ten times smaller than the steady state. Pure noble gas bubbles turn on to their steady state values on a much shorter time scale (say less than 0.2 s). During the transient period light from an air bubble is weaker than light from an Argon bubble but in the steady state the air bubble is brighter. In view of the long time scale required for the establishment of sonoluminescence from a single bubble of air it is concluded that this is a fundamentally different phenomenon from the transient multibubble sonoluminescence that has been studied since its discovery in 1934. [Work supported by the U.S. DOE Division of Advanced Energy Projects.]