Numerical and experimental investigation on water shocks due to pulsed discharge in accelerators

Pulsed discharge in water produces transient shockwaves which are harmful to the ceramic interface in accelerators. In this paper, with a self-consistent underwater explosive approach, a finite element model was set up to investigate the shockwave behaviors, and the pressure-time history and ceramic mechanical response to shockwaves were presented. In order to get the pressure profile and verify the calculation models, a small-scaled water switch test was conducted based on a 10-stage Marx generator (40~50 ns pulse duration, 100~300 kV amplitude). The variations of peak pressure, shock velocity and main pulse width under different breakdown conditions were measured. According to the calculation of empirical formulas, about 17% of the discharge energy was transformed into the mechanical ene