Relationship between a standing-wave field and a sonoluminescing field

The relationship between a sound field and a multibubble sonoluminescing fi eld has been studied experimentally and analytically to clarify the sonoche mical reaction field. The variation of each field in a rectangular glass ce ll filled with distilled water or a luminol solution was investigated while changing experimental conditions such as driving frequency, applied voltag e to the transducer, and thickness of the cell bottom. As for the sonolumin escing field; the intensity of sonoluminescence (SL) was measured and its d istribution was observed. As for the sound field, sound energy density was analyzed theoretically and sound pressure distribution was observed optical ly. Comparing them, it became clear that SL occurred at pressure antinodes of a standing-wave field in the cell. There are upper and lower thresholds of the sound pressure for SL to occur. This explains the amplitude dependen ce and spatial nonuniformity of SL in a standing-wave field.