Parametric dependence of the line emissions in sonoluminescence

Abstract

Based on a series of spectral measurements of sonoluminescence, this paper investigates parametric dependence of the line emissions in single bubble sonoluminescence (SBSL) and multi-bubble sonoluminescence (MBSL). The experiments show that the intensities of the OH * radical line, the sodium line and the noble gas lines in SBSL are relevant to the driving pressure of the acoustic field and the concentration of the noble gases dissolved in host liquids. The intensity of line emissions in total spectrum increases with the decreasing driving pressure and the increasing concentration of noble gases. Parametric dependence of line emissions in MBSL consists with that in SBSL. Line emissions in sonoluminescence should correspond to lower temperature inside the bubbles. SBSL and MBSL share the same spectral structure, and the difference between them found by previous experiments should result from the different temperatures inside bubbles.sonoluminescence, line spectra, parametric dependence, driving pressure, noble gas

Line Emission of Sodium and Hydroxyl Radicals in Single-Bubble Sonoluminescence

“…It is noteworthy that the strong similarity in the shapes of SL spectra of OH • radicals for SBSL and MBSL indicates similar populations of vibrational exciting states for these species in single-bubble and multibubble systems. In other words, the electronic vibration structure of OH • lines reveals the similarity in the intrabubble conditions for SBSL and MBSL under conditions favorable for the appearance of line emission in SBSL spectra similar to that observed by Liang …”

“…For water pre-equilibrated with ∼1 mbar of argon at room temperature T bb is ∼17 100 K. It is not dependent on the applied acoustic pressure. When the argon pressure is increased to 70 mbar, as optimized by Liang, T bb decreases to ∼11 100 K. When a NaCl solution under 70 mbar of Ar is considered, T bb is similar to the value obtained in pure water. Besides the continuum the SBSL spectra of water with an argon pressure of 70 mbar exhibit a line emission at 310 nm (inset in Figure ) with a shoulder around 280 nm.…”

“…The spectra of sodium chloride solutions at 70 mbar of argon exhibit two striking features. The first one, as outlined by Liang, is that only at argon pressures of some tens of mbar the SL continuum exhibits line emissions of OH • and Na*. The acoustic pressure threshold for radical production and sodium reduction and excitation is above the threshold for stable cavitation, which is in the range of 0.8−0.9 bar depending on the experimental conditions, and slightly below the threshold for the emission of the broad-band continuum.…”

Modeling of ultrasound contrast agents bubble dynamics with modified surface tension coefficient

“…As shown in Figure 1, a three-layer system has two interfaces, namely the inner boundary of the shell (subscript 1) and the outer one (subscript 2), with the radius of R 1 and R 2 respectively. In order to simplify the system, we assume the volume of the encapsulating layer holds a constant value, namely the bulk volume of the shell 3 3…”

“…ultrasound contrast agents, dynamic model, surface tension coefficient Bubble dynamics has been concerned for a long time in the research of ultrasound applications. A series of theoretical and experimental works considering the impact of bubble dynamics on sonoluminescence have been carried out [1][2][3] . In recent years, more and more attentions are paid to bubble dynamics in the fields of biomedical applications.…”