PLURAL SONOLUMINESCING BUBBLES IN ACOUSTIC FIELDS OF HIGHER MODE

As many as four sonoluminescing bubbles were created in the spherical acoustic resonator driven by a pair of Langevin transducers. The bubbl es were trapped symmetrically off center in the horizontal plane passi ng through the center of the flask. Vibrations were found to be in the aspherical mode with two nodal planes, as analyzed using a laser Dopp ler vibrometer. The emission spectrum, having a peak in the ultraviole t region, showed no significant structure.