OBSERVATION OF ISOTOPE EFFECTS IN SONOLUMINESCENCE

The spectrum of sonoluminescence emitted by single bubbles of H-2, D-2 , He-3, and He-4 trapped in H2O and D2O has been measured. We find tha t heavy water has a dramatic effect on the spectrum of hydrogenic gase s, yielding a blackbody-type spectrum with a spectral peak at about 40 0 nm. The explanation of why such a small change in the driving fluid leads to such a large spectral shift is unknown.