摘要：Light emission in single-bubble sonoluminescence (SBSL) experiments results
from the extreme conditions reached during the very strong collapse of a gas
bubble driven into non-linear radial oscillations. Recent experiments
achieved an important enhancement (by a factor 2700) in the light emitted
from the bubble by using Argon bubbles within aqueous H2SO4 solutions.1 The
very marked increase in SBSL intensity allowed well resolved spectra
determination revealing the presence of spectral lines coming from atomic
(Ar) emission and other molecular and ionic processes. In the present work
we calculate the hydrodynamic motion of the gas inside the bubble
using compressible Navier-Stokes equations in spherical symmetry in order to
obtain instantaneous temperature and density profiles. Taking the previous
results as input we apply a spectral model which incorporates atomic physics
and takes into account the finite opacity of the gas under the extreme
conditions at bubble collapse. Results are in agreement with timescale of the
light pulse width and continuum part of experimental spectra measured.1
Besides we found that brighter bubbles are not necessarily hotter bubbles.
The full model presented constitutes an adequate starting point for modelling
line emission observed in experiments.
