Towards higher energy density processes in sonoluminescing bubbles

Abstract

A bubble in a standing sound wave in water pulsates with such power that, as its minimum radius is approached, the interior undergoes a first order phase transition to a dense plasma. A pulse of blackbody radiation is emitted with temperatures ranging from 6,000K to 20,000K depending on the gas inside the bubble. To date experiments on sonoluminescence inside water, sulfuric acid and phosphoric acid have yielded similar blackbody temperatures. These liquids are hydrogen bonded and so the question arises as to whether their compressibility limits the energy concentration achieved by Sonoluminescence. Liquids where repulsion between nearest neighbor electron shells \such as small ion molten slats\ should be more incompressible. Scaling law estimates of the energy loss due to: acoustic radiation; shear viscosity, and compressibility of the surrounding fluid will be discussed with the goal of predicting a fundamentally new regime of sonoluminescence.