Water temperature dependence of single bubble sonoluminescence threshold.

Water temperature dependence of single bubble sonoluminescence (SBSL) threshold has been experimentally measured to perform measurements at different temperatures on the very same bubble. Results show lower thresholds, i.e. an easier prime of mechanism, of sonoluminescence at lower water temperatures. Dependence is almost linear at lower temperatures while between 14 degrees C and about 20 degrees C the curve changes its slope reaching soon a virtual independence from water temperature above about 20 degrees C.