Post-breakdown dielectric recovery characteristics of water for high-repetition-rate switch

Water plays a pivotal role in pulse switches, owing to its fast recovery characteristic and high dielectric strength. In this paper, we empirically studied the effect of behavior of vapor bubbles on the dielectric recovery characteristics of water during the post-breakdown. The experimental medium is distilled water, and highly pressurized CO ₂ in its supercritical phase is used as a comparative medium to test the voltage recovery ratio. The dielectric recovery characteristics of water was explained by alternating expansion-contraction bubble behaviors, including bubble density variation in the second oscillation stage. The experimental results showed that water showed a shorter recovery time (2 ms), and it could be regarded as a promising medium for high-repetition-rate switch. The motion of second oscillating bubbles resulted in a considerably short recovery time.