Abstract
We have observed an extraordinary light emission during multi-bubbles sonoluminescence (MBSL)
measurements in He saturated water at 1MHz. The light was orange, and its spectrum showed He line around 700 nm. The
ground electrode of the transducer, which was exposed to sample liquid, was damaged by cavitation erosion. The electric
field leaked from the transducer affected sonoluminescing bubbles near the ground electrode. In this study, we have
experimentally investigated the effect of electric fields externally controlled on MBSL. We applied direct-current (DC)
voltage (~250 V) or alternating-current (AC) (250V) voltage which synchronizing with the ultrasound frequency using
platinum needle as electrode. MBSL was apparently changed when applying DC voltage. The MBSL intensity increased by
applying +250 V compared with that with no voltage was applied.
