Bradley P. Barber
Phys. Dept., UCLA, Los Angeles, CA 90024
The dynamic sound field pressure P[sub a] required to generate sonoluminescence (SL) from a single trapped bubble is a little higher than the ambient pressure P[sub 0] (e.g., P[sub a](approximately equal to)1.2P[sub 0]). Since the acoustic energy density is proportional to the square of P[sub a] observation of SL at lower drive levels would imply that even greater degrees of energy concentration accompany the transduction of sound into light. Motivated by this perspective, the dependence of SL on ambient pressure is being measured. Light emission at P[sub 0]=0.3 Atm has already been achieved. Pressures higher than an atmosphere are also being investigated, especially with attempts to find single bubble SL in liquids other than water. [Work supported by the U.S. DOE Division of Advanced Energy Projects.]