Thermal Instability in Magnetized Solar Plasmas

  1. J. H. Waite Jr.,
  2. J. L. Burch and
  3. R. L. Moore
  1. J. T. Karpen,
  2. S. K. Antiochos,
  3. J. M. Picone and
  4. R. B. Dahlburg

Published Online: 18 MAR 2013

DOI: 10.1029/GM054p0099

Solar System Plasma Physics

Solar System Plasma Physics

How to Cite

Karpen, J. T., Antiochos, S. K., Picone, J. M. and Dahlburg, R. B. (1989) Thermal Instability in Magnetized Solar Plasmas, in Solar System Plasma Physics (eds J. H. Waite, J. L. Burch and R. L. Moore), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM054p0099

Author Information

  1. Naval Research Laboratory, Washington, D.C. 20375

Publication History

  1. Published Online: 18 MAR 2013
  2. Published Print: 1 JAN 1989

ISBN Information

Print ISBN: 9780875900742

Online ISBN: 9781118664315

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Keywords:

  • Space plasmas;
  • Sun;
  • Magnetosphere;
  • Astrophysics

Summary

In astrophysical plasmas such as the solar corona or the interstellar medium, the radiation-driven thermal instability might explain the formation of cool, dense regions embedded in a hotter, more rarefied medium. In the present work, we extend our previous investigation of this phenomenon by simulating the response of a magnetized solar transition-region plasma to a spatially random magnetic-field perturbation, where the magnetic field is perpendicular to the computational plane. Our investigation has determined the effects of varying the plasma β and the heating mechanism. We find that the presence of the magnetic field, the value of the plasma β, and the heating rate significantly influence the size and number of the condensations, as well as the evolutionary time scale. The asymptotic final state is the same in all cases: a uniform, nearly static plasma in which the density and magnetic field strength are close to the initial values but the temperature has dropped to ∼104 K. The time scale over which the plasma evolves to this final state increases greatly as β decreases and depends sensitively on the heating rate.