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.
其他摘要：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.
