The time difference in emission of light and pressure pulses from oscillating bubbles

Anotace: Oscillations of spark-generated bubbles are studied experimentally. In this work, an attention is paid to the time difference in the radiation of light flashes and pressure pulses from a bubble at the final stages of the first bubble contraction and the early stages of the first bubble expansion. It is found that light and pressure pulses are not radiated synchronously. In some experiments, the light flashes are radiated before the pressure pulses by a few μs and in other experiments, the light flashes are radiated later than the pressure pulses by a few μs. The time difference in the radiation of the two pulses is examined in detail in relation with the bubble size, bubble oscillation intensity, maximum value of the light flash and the width of the light flash. It is shown that the magnitude of the time differences is very weakly correlated with the bubble size, intensity of oscillation and intensity of the light flashes and that the magnitude of the time differences is only moderately correlated with the light flashes widths.