Abstract:
Current models of the light emission mechanism for a sonoluminescing bubble are based on experimentally measured spectra in the visible and near-ultraviolet region. Four proposed quantitative theories for the emission mechanism differ by over 25 orders of magnitude in the microwave region. An experimental setup used to measure this predicted microwave emission is described. The sensitivity of the radiometer is greater than the predicted bremsstrahlung emission by a factor of 10[sup 6] and is insufficient to detect the other mechanisms. Lack of detection of microwaves indicates that bremsstrahlung is not the mechanism of electromagnetic radiation for a sonoluminescing bubble. [Work supported by ONR.]