抄録
We aim to clarify the mechanism of the power dependence of sonoluminescence (SL) under sound fields having free end or fixed end. We observed SL in the three cases of boundaries, free surface end, free end covered with thin PET film, and fixed end with SUS plate. SL intensity increased as power increases and showed a maximum and then decreased and perfectly quenched at higher powers. We also observed shadowgraph of acoustic bubbles using a high-speed camera and measured acoustic emission spectra in the case of free end using a broadband PVDF sensor. In conclusion, SL intensity increases with acoustic power since active bubble population increases. SL decreases when bubble clusters appeared. SL perfectly quenched at higher powers where only bubble clusters were observed.
