Radiative and reconnection instabilities: filaments and flares
The linear interaction of the radiative cooling (Field, 1965) and resistive tearing (Furth, Killeen and Rosenbluth, 1963) instabilities in sheared magnetic fields, which may lead to solar coronal filaments and flares, respectively, is studied. The dynamics and energetics are shown to be coupled by Coulomb resistivity eta(T) and/or by plasma compressibility, and the resulting MHD system is solved numerically to provide growth rates and eigenfunctions. Magnetic tearing in an inviscid and incompressible plasma is first treated. The local evolution of the temperature (and thus of the resistivity) is described by an energy equation which includes Joule heating and optically-thin radiation R(rho,T). Without radiation, there are two distinct solutions above a critical value of the magnetic Reynolds number S, a tearing-like and a Joule-heating mode. Below this point, the growth rates coalesce into a conjugate pair. It is demonstrated that, although the energetics are significantly affected by compressional effects, the dynamics are not, leaving the tearing mode relatively unaffected. Inhibition of plasma condensation in the radiative mode by perpendicular thermal conduction, most important in the short wavelength limit, is then demonstrated. Finally, results are applied to the characteristic unstable phenomena of solar activity, and are applied to the interrelations between filaments and flares.
- Research Organization:
- California Univ., Irvine (USA)
- OSTI ID:
- 5926312
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
PLASMA FILAMENT
PRODUCTION
SOLAR CORONA
SOLAR FLARES
TEARING INSTABILITY
MAGNETIC FIELDS
RADIATIVE COOLING
SHEAR
ATMOSPHERES
COOLING
INSTABILITY
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
SOLAR ACTIVITY
STELLAR ATMOSPHERES
STELLAR CORONAE
640104* - Astrophysics & Cosmology- Solar Phenomena
700107 - Fusion Energy- Plasma Research- Instabilities