Multibubble sonoluminescence in interacting fields of different frequencies

Multibubble sonoluminescence has been studied in conditions of low frequency field (LF), high-frequency field (HF) and combined (HF+LF) sonification. It is shown that combined action of the two fields can exceed the sum of the effects of each of them acting separately, i.e. there is considerably nonadditive summation of the effects. The highest effect has been reached in the case when the HF field was pulse modulated and the LF field was switched on for a short time (0.1–60 sec.) After deenergizing the LF field, the intensity of sonoluminescence (SL) generated by the HF field increases at first in a stepwise manner. After this jump the SL intensity slowly decreases tending to some limiting value, which usually is higher than the SL intensity before impact by the LF field.