Sonoluminescence of Aqueous Solutions of CaCl2 and NaCl: The Effect of Concentration

The structure of the sonoluminescence spectra of argon-saturated aqueous solutions of CaCl2 and NaCl of various concentrations is considered in detail. The frequency of ultrasound is 20 kHz, and the output power is 18 W. The spectrum of the CaCl2 solution changes considerably as the concentration rises. The intensity of the continuum passes through a maximum near the saturation concentration. Atomic, ionic, and molecular metal lines are observed for medium concentration values and disappear at high concentrations. Similar behavior is displayed by the spectra of NaCl solutions. The differences between the spectra are explained by the change in the vapor-gas content of the bubbles and the nature of their population, from large and non-inertial to small and pulsating inertially.

Automated summary

The structure of sonoluminescence spectra in argon-saturated aqueous solutions of various concentrations of CaCl2 and NaCl is examined. Using ultrasound at a frequency of 20 kHz and output power of 18 W, the spectrum of CaCl2 solution significantly changes with increasing concentration. The intensity of the continuum reaches a maximum near saturation concentration. Atomic, ionic, and molecular metal lines are observed at medium concentrations, but disappear at high concentrations. Similar behavior is observed for NaCl solutions. The differences in spectra are attributed to changes in vapor-gas content of the bubbles and their population, transitioning from large and non-inertial to small and pulsating inertially.