Joseph C. Jankovsky
Jeffrey A. Ketterling
Robert E. Apfel
Ctr. for Ultrasonics and Sonics, Yale Univ., New Haven, CT 06520-8286
An experimental apparatus has been designed to measure the physical properties of low-frequency sonoluminescence (SL) (15 kHz). Radial motion of the bubble has been measured by Mie scattering and also by a new method, which images the bubble through a magnifying CCD camera illuminated by a strobing LED lamp. The light emission of SL is measured by a photomultiplier tube. An automated gas handling system has been constructed in order to measure the effects of various gas mixtures and concentrations on SL. The system consists of voltage actuated valves, a mixing vessel, and pressure sensors, which are interfaced to a computer and controlled using the LabVIEW programming environment. With the lower frequencies and the resulting larger bubbles, it is hoped that the parameter space for this region of SL can be mapped out. [Work supported by NASA through JPL Contract No. 958722.]