9312205 Williams This exploratory proposal is to study the properties of synchronous sonoluminescence (SSL) in fluids in order to gain some fundamental insights into the nature of the phenomenon. The exact mechanism by which there is a conversion of sound into light (first observed in air bubbles in water) is not understood, although there is some evidence that the compressional heating of the gas is enough to yield appreciable black-body radiation. However, it is not clear whether there are also chemical or atomic processes occurring in the hot gas or plasma which may control the emission. The work in this proposal is composed of three main thrusts: The study of the oscillation properties of a single bubble trapped at the center of a spherical continuous wave acoustic resonator. The investigation of the intensity of the light emitted by the bubbles as a function of the applied acoustic fields. The measurement of the spectrum of the emitted light in the visible to ultra-violet wavelength range. The SSL research will be undertaken in cryogenic liquids as these fluids have several advantages over water. They have high chemical purity and the spectroscopic studies can be carried out over a wider wavelength range. %%% This exploratory proposal is to study the properties of synchronous sonoluminescence (SSL) in fluids in order to gain some fundamental insights into the nature of the phenomenon. The exact mechanism by which there is a conversion of sound into light (first observed in air bubbles in water) is not understood. There is some evidence that the compressional heating of the gas is enough to cause the emission of radiation. However, it is not clear whether there are also chemical or atomic processes occurring in the hot gas or plasma which may control the emission. The work in this proposal is composed of three main thrusts: The study of the oscillation properties of a single bubble trapped at the center of a spherical continuous wave acoustic resonator. The investigation of the intensity of the light emitted by the bubbles as a function of the applied acoustic fields. The measurement of the spectrum of the emitted light in the visible to ultra-violet wavelength range. The SSL research will be undertaken in cryogenic liquids as these fluids have several advantages over water. They have high chemical purity and the spectroscopic studies can be carried out over a wider wavelength range. ***
