Study of underwater shock waves and cavitation bubbles generated by pulsed electric discharges

The paper reports on generation of controllable underwater shock waves through the use of a magnetic pulsed compression circuit as the power source of underwater spark discharge to aid in improving accuracy and safety in medical applications. In the present work, we were able to widely change the peak pulsed voltages by the magnetic pulsed compression circuit. Sensitivity of underwater shock wave pressure to peak voltage variation was obtained near the electrodes in the 200 to 400 MPa range with voltage amplitudes from 10 to 18 kV. Effects of pulsed electric discharge parameters such as the voltage amplitude and pulse duration on characteristics of cavitation bubbles and shock waves were observed and analyzed. Visualization results and image analysis allowed evaluation of radii and collapse times of cavitation bubbles and their generated shock waves pressures. Pressures of underwater shock waves were also measured by a fiber optic probe hydrophone and were compared with the visualization analyses results.