Direct observation of cavitation fields at 23 and 515 kHz

Direct observation of cavitation fields using photography, sonoluminescence and luminol “mapping” is reported for a 23 kHz horn sonicator and a 515 kHz plate transducer system. The effect of sound intensity and added surfactant on the cavitation fields is described. The observations support previously reported results suggesting significant differences in the cavitation fields between the two sonication systems.