Sonoluminescence from Glycerine–Water Mixtures

Abstract

THE sonoluminescence from glycerine–water mixtures extending over the full range of 0–100 per cent glycerine has been investigated. A specially distilled supply of glycerine of 99.9 per cent purity was obtained and the sample of volume 5 ml. was contained in a 15-ml. quartz beaker cooled by circulating cold water. Fresh tap water was used, as tests showed that this gave the same results as distilled water. Cavitation was produced by a magnetostrictive window-type transducer coupled to a titanium double quarter-wave velocity transformer, the system being adjusted to deliver a constant acoustic power of 10 W at a frequency of 21.5 kc s over an area of 0.7 cm². The transducer was monitored by an oscilloscope and valve voltmeter connected to a crystal accelerometer pick-up fixed to the transducer. The sonoluminescence was measured by a 13-stage E.M.I, photomultiplier tube ‘6255B’ sensitive from 1650 Å to 6500 Å, and the signal was detected by a high-impedance valve voltmeter.