Ideal kink instabilities in line-tied coronal loops - Growth rates and geometrical properties

Journal Article · Thu Feb 01 04:00:00 EST 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/168397· OSTI ID:6851598

Velli, M; Hood, A W; Einaudi, G ^[1]

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1. Saint Andrews Univ. (Scotland) Firenze, Universita, Florence (Italy)

A detailed analysis of the ideal kink instability in line-tied cylindrically symmetric coronal loops is presented. Using a rapidly converging Fourier series expansion technique, the growth rate, as well as the eigenfunction, of ideal m = 1 kink modes is calculated for two topologically distinct models of force-free static MHD equilibria: one in which all the magnetic field lines are connected to the photosphere and one presenting a polarity inversion surface. The growth rates depend crucially on the loop length. Loops of the former type are found to be more unstable, and possess higher growth rates, than loops of the latter type, which are unstable to sausage-tearing modes and may also be unstable to m = 1 resistive kink modes. Applications of these results to the structure of coronal loops are presented. 14 refs.

• OSTI ID: 6851598
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 350; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
EQUILIBRIUM
FLUID MECHANICS
FOURIER ANALYSIS
HYDRODYNAMICS
INSTABILITY
KINK INSTABILITY
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
MECHANICS
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
SOLAR ACTIVITY
SOLAR CORONA
SOLAR PROMINENCES
STABILITY
STELLAR ATMOSPHERES
STELLAR CORONAE
TEARING INSTABILITY