Sonoluminescence Emission in Interacting Fields

The influence of the intensities of both interacting low frequency (LF) and high frequency (HF) fields on resulting sonoluminescence emission as well on the generation of the LF field on sonoluminescence generated by the HF field was studied. It was shown that the generation of the new cavitation nuclei upon collapse driven by the LF field is the main factor in superadditive enhancement of SL emission from a multibubble cavitation zone. Factors connected with the direct interaction of the fields such as interference of the fields or generation of waves with combined frequencies play a role in the case when the intensities of the fields when operating separately are lower than their SL thresholds. The phenomena of strong afteraction (memory effect) of the LF field on cavitation generated by the HF field is explained by the fact that new nuclei generated by the LF field have rather long “life” period in the liquid and disappear due to slow diffusion of air from the bubble.