Single Sweep Oscillograph Traces of Sonoluminescence

Abstract

IT has been reported^1–7 that sonoluminescence, which is a weak light emission accompanying ultrasonic cavitation in certain liquids, occurs as a discrete flash once every cycle of the stimulating acoustic field. However, I have recently obtained photographs of single-sweep oscillograph traces of the anode current of a photomultiplier used to observe sonoluminescence, and these photographs show that whereas sonoluminescence does occur as pulses always at roughly the same phase of the sound field, the pulses do not occur with every cycle (Figs. 1 and 2. The upper member of each of the pairs of traces shown in these photographs is the sound field).