An Investigation on the Net Charge on Gas Bubbles Induced by 0.75 MHz under standing wave condition

Sonoluminescence has been attributed by some authors to compression of gas inside collapsing acoustically in- duced cavities (or even to pulsation violent stable cavities). This adiabatic compression is believed to raise the tem- perature of the gases by up to 10,000 K which radiate in the visible spectrum. An alternative explanation has been proposed by others as: the changes in charge density on bubble surface during compression leads to electrical dis- charge (in microscopic scale) and they believe to that this process causes emission of light from the cavity. In this work we report on the measurement of the net charge induced acoustically on the bubble by means of the motion of bubbles in distilled water while an external electric field applied. The motion of the bubbles is recorded on a photo- graphic film during 1 second exposure hence the stationary bubbles appear as points and moving bubbles as lines. The radius of the bubble and hence the bubble charge can be estimated from the velocity of bubble provided by the length of the line.