The rapid heating of coronal plasma during solar flares - Nonequilibrium ionization diagnostics and reverse currents
1978; IOP Publishing; Volume: 224; Linguagem: Inglês
10.1086/156453
ISSN1538-4357
AutoresPaul R. Shapiro, J. W. Knight,
Tópico(s)Solar and Space Plasma Dynamics
Resumoview Abstract Citations (12) References (29) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The rapid heating of coronal plasma during solar flares: nonequilibrium ionization diagnostics and reverse currents. Shapiro, P. R. ; Knight, J. W. Abstract A simple method is presented for diagnosing the electron temperature and density of a rapidly heated, coronal-type plasma from observable, nonequilibrium enhancements of X-ray line emission. This method, it is argued, is applicable to the study of solar flares. Accordingly, theoretically predicted line enhancements are given for a representative selection of X-ray lines prominent in the prefiare coronal emission spectrum. Some of these predicted line enhancements should soon be observable with instruments aboard the Solar Maximum Mission. Mechanisms, involving energetic electron beams and reverse currents, for the heating of coronal flare plasma rapidly enough to produce these nonequilibrium effects are examined. A timedependent calculation of Joule heating by the reverse current is presented for two illustrative electron beam strengths. For the first, classical Coulomb resistivity is assumed for the ambient plasma; for the second, anomalous resistivity is assumed to result from the onset of electrostatic ion-cyclotron turbulence. The results suggest that rapid heating can occur by a variety of mechanisms. Subject headings: plasmas - Sun: corona - Sun: flares - Sun: X-rays Publication: The Astrophysical Journal Pub Date: September 1978 DOI: 10.1086/156453 Bibcode: 1978ApJ...224.1028S Keywords: Gas Ionization; Plasma Diagnostics; Plasma Heating; Solar Corona; Solar Flares; Electron Beams; Electron Density (Concentration); Electron Energy; Fine Structure; Ion Acoustic Waves; Line Spectra; Ohmic Dissipation; Resistance Heating; Solar X-Rays; Stellar Models; Solar Physics; Plasma:Solar Corona; Plasma:Solar Flares; Solar Corona:Heating; Solar Flares:X Rays full text sources ADS |
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