Acoustic multibubble cavitation in water: A new aspect of the effect of a rare gas atmosphere on bubble temperature and its relevance to sonochemistry.

Acoustic cavitation generates transient microbubbles with extremely high temperatures and high pressures, which can provide unique reaction routes. The maximum bubble temperature attained is widely known to be dependent on the polytropic index and thermal conductivity of the dissolved gas. Here, we show for the first time experimental evidence that the bubble temperature induced by a high frequency ultrasound is almost the same among different rare gases and the chemical efficiency is in proportion to the gas solubility of rare gases, which would be closely related to the number of active bubbles.