Astrophysically relevant experiments on radiation transfer through plasmas with large velocity gradients

  • J. S. Wark
    Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
  • S. J. Rose
    Rutherford Appleton Laboratory, Chilton, Didcot, Oxon. OX11 0QX, United Kingdom
  • P. K. Patel
    Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
  • A. Djaoui
    Rutherford Appleton Laboratory, Chilton, Didcot, Oxon. OX11 0QX, United Kingdom
  • O. Renner
    Institute of Physics, Czech Academy of Sciences, Prague 18040, Czech Republic
  • A. Hauer
    Los Alamos National Laboratory, Los Alamos, New Mexico 87545

抄録

<jats:p>The transfer of radiation through plasmas with large velocity gradients is of relevance to several astrophysical situations, such as supernova explosions, maser operation, and stellar winds. Similar conditions often prevail in laser-produced plasmas, with velocity gradients of order 109 s−1 significantly altering the effective optical depth and line shape. Some of the simplest cases to study experimentally are the hydrogenic resonance lines. Experiments performed in both planar and cylindrical geometry, comparing the observed line profiles with those modeled using a one-dimensional Lagrangian hydrocode, incorporating average-atom nonlocal thermodynamic equilibrium (non-LTE) atomic physics are described. The opacity effects on the ion populations are treated within the escape factor approximation, taking into account the effects of the velocity gradient. The hydrocode gives time- and space-dependent values of the electron and ion densities, excited state fractions, electron and ion temperatures, and velocities. The hydrodynamic output is post-processed with a radiative transfer routine to construct the simulated line shape. Details of the experiments and results are presented, and relevance to the astrophysical situations discussed.</jats:p>

収録刊行物

被引用文献 (3)*注記

もっと見る

キーワード

詳細情報 詳細情報について

問題の指摘

ページトップへ