COMPARISONS OF SONOLUMINESCENCE FROM SINGLE-BUBBLES AND CAVITATION FIELDS - BRIDGING THE GAP

Sonoluminescence (SL) refers to the generation of light through the en ergetic pulsations of acoustic cavitation bubbles in a liquid. For yea rs, SL was observed primarily in cavitation fields. These bubbles are believed by many to undergo near-adiabatic compression, resulting in t he heating of the bubble contents and the subsequent emission of light . Recently, researchers have discovered a 'new' form of sonoluminescen ce in which light is observed to emanate from a single bubble undergoi ng very large volume excursions. The mechanism for light production is unknown, but many believe it is due to a rapid heating of the central core by an imploding shock wave. Based in part on the emission time s cales, there is a common belief that the two forms of SL are quite dis tinct. We address this issue by comparing the two phenomena with regar ds to their light-flash durations and emission spectra - leading to so me surprising differences and similarities. (C) 1997 Elsevier Science B.V.