THE INFLUENCE OF LIQUID TEMPERATURE ON THE SONOLUMINESCENCE HOT-SPOT

An explanation is provided for the influence of relatively small chang es in liquid temperature on the hot spot within a sonoluminescence bub ble. This influence derives from a change in the (stable) equilibrium mass of the bubble due to a variation of the gas solubility in the liq uid with temperature. If the acoustic drive amplitude is held constant , a change in the liquid temperature has a large or small effect depen ding on the variability of the solubility with temperature. For a gas like xenon, which has rapidly decreasing solubility in water with incr easing temperature, a decrease in water temperature shifts the stable mass exchange equilibrium to a smaller bubble size. This increases the ratio of maximum to minimum bubble radius over an acoustic cycle, res ulting in a much higher hot spot temperature. In contrast helium has v ery little variation of solubility with temperature near room temperat ure; therefore the hot spot temperature is relatively insensitive to v ariations in the liquid temperature outside a helium bubble. (C) 1998 Acoustical Society of America. [S0001-4966(98)04910-8]