Theory of Light Emission in Sonoluminescence as Thermal Radiation

TL;DR

This paper develops a comprehensive thermal radiation model for single-bubble sonoluminescence, using multilayered sphere absorption properties and hydrodynamic simulations to match experimental observations.

Contribution

It introduces a novel theoretical framework combining Kirchhoff's law with multilayered sphere modeling for SBSL radiation.

Findings

Successfully reproduces key experimental SBSL features

Uses hydrodynamic simulations to determine bubble structure

Provides a quantitative prediction of thermal emission

Abstract

Based on the model proposed by Hilgenfeldt {\it at al.} [Nature {\bf 398}, 401 (1999)], we present here a comprehensive theory of thermal radiation in single-bubble sonoluminescence (SBSL). We first invoke the generalized Kirchhoff's law to obtain the thermal emissivity from the absorption cross-section of a multilayered sphere (MLS). A sonoluminescing bubble, whose internal structure is determined from hydrodynamic simulations, is then modelled as a MLS and in turn the thermal radiation is evaluated. Numerical results obtained from simulations for argon bubbles show that our theory successfully captures the major features observed in SBSL experiments.