Experimental study of light emission from spark generated bubbles

Spark discharges in water have been used to generate oscillating bubbles. During a spark discharge intensive optic and acoustic pulses are emitted. The discharge channel expands violently and converts into a radially oscillating almost spherical bubble. The plasma in the bubble interior cools down during the growth phase which follows the discharge. However, during the next compression phase the plasma in the bubble interior is compressed and heated and optic and acoustic pulses are emitted again. Using a photodiode and a hydrophone the optic and acoustic emission from the spark discharge and subsequent bubble oscillation phases could be recorded simultaneously. By analyzing the acoustic wave the bubble size and its oscillation intensity can be determined. However, now these data are accompanied by a light emission record which significantly enhances understanding of the spark bubble behavior.