An Energy Storage Process and Energy Budget of Solar Flares

1980 ◽  
Vol 91 ◽  
pp. 231-234 ◽  
Author(s):  
K. Tanaka ◽  
Z. Smith ◽  
M. Dryer
Keyword(s):  
Energy Storage ◽  
Magnetic Fields ◽  
Energy Budget ◽  
Solar Flares ◽  
Horizontal Shear ◽  
Storage Process ◽  
Flare Energy ◽  
Upward Velocity ◽  
Shear Motion ◽  
Image Position

The flare energy is generally considered to be stored in stressed (twisted or sheared) magnetic fields. Origin of the stress may be either intrinsic or due to horizontal shear motion (Tanaka and Nakagawa 1973) or due to propagation of twist from below (Piddington 1974). Characteristic magnetic configurations in the great activities (inverted, twisted δ-configuration; Zirin and Tanaka 1973) suggest an inherent shape of fluxtube for these regions: a twisted magnetic knot. Further, evolutionary characteristics such as rapid growths of spots and growth of twist in parallel with apparent shear motion of spot, together with the fact that the shear motion is associated with upward velocity (Tanaka and LaBonte 1979), suggest a continuous emergence of such a twisted knot from below throughout the activity (Tanaka 1979). In this model (Fig. 1) the flare energy may be supplied directly into the corona as the twisted portion of the fluxtube emerges out. The amount of energy supplied between t0 and t may be equated to the energy contained in the twist (ɸ) between z1 and z2,

Magnetic fields in solar flares

2007 ◽  
Vol 13 (1s) ◽  
pp. 99-100
Author(s):  
V.G. Lozitsky ◽  
Keyword(s):  
Magnetic Fields ◽  
Solar Flares

scholarly journals Gamma-rays from Solar Flares

2000 ◽  
Vol 195 ◽  
pp. 123-132 ◽  
Author(s):  
R. Ramaty ◽  
N. Mandzhavidze
Keyword(s):  
Energy Release ◽  
Gamma Rays ◽  
Solar Flares ◽  
Gamma Ray ◽  
Particle Interaction ◽  
Mass Motion ◽  
Relativistic Electrons ◽  
Total Energy Release ◽  
Flare Energy ◽  
Accelerated Particles

Gamma-ray emission is the most direct diagnostic of energetic ions and relativistic electrons in solar flares. Analysis of solar flare gamma-ray data has shown: (i) ion acceleration is a major consequence of flare energy release, as the total flare energy in accelerated particles appears to be equipartitioned between ≳ 1 MeV/nucleon ions and ≳ 20 keV electrons, and amounts to an important fraction of the total energy release; (ii) there are flares for which over 50% of the energy is in a particles and heavier ions; (iii) in both impulsive and gradual flares, the particles that interact at the Sun and produce gamma rays are essentially always accelerated by the same mechanism that operates in impulsive flares, probably stochastic acceleration through gyroresonant wave particle interaction; and (iv) gamma-ray spectroscopy can provide new information on solar abundances, for example the site of the FIP-bias onset and the photospheric 3He abundance. We propose a new technique for the investigation of mass motion and mixing in the solar atmosphere: the observations of gamma-ray lines from long-term radioactivity produced by flare accelerated particles.

scholarly journals Quasi–Static Evolution of Force–Free Magnetic Fields and a Model for Two–Ribbon Solar Flares

1985 ◽  
Vol 107 ◽  
pp. 221-224
Author(s):  
J. J. Aly
Keyword(s):  
Magnetic Fields ◽  
Solar Flares ◽  
Free Field ◽  
Qualitative Theory ◽  
Force Free Field ◽  
Open Configuration

We show that a sheared 2–D force–free field can evolve in a quasi–static way towards an open configuration, and apply this result to a qualitative theory of two–ribbon solar flares.

scholarly journals The Magnetic Fields of Pulsars

1974 ◽  
Vol 64 ◽  
pp. 187-187
Author(s):  
D. M. Sedrakian
Keyword(s):  
Magnetic Field ◽  
Angular Velocity ◽  
Magnetic Fields ◽  
Relative Motion ◽  
Kinematic Viscosity ◽  
Charged Particles ◽  
Normal Fluid ◽  
Inertia Effects ◽  
Generation Mechanisms ◽  
Image Position

Two generation mechanisms of magnetic fields in pulsars are considered.If the temperature of a star is more than 108K, the star consists of a normal fluid of neutrons, protons and electrons. Because the angular velocity of pulsars is not constant dω/dt ≠0, inertia effects can occur, and generate magnetic fields through the relative motion of charged particles with different masses. The kinematic viscosity of electrons is 30 times larger than that of protons; hence electrons move with the crust, but the proton-neutron fluid will move relative to the electrons. The magnetic momentum can be calculated by the following formula where Meff = Mp + Mn(Nn/Np), R = radius of the star, σ = conductivity. For typical neutron stars we have dω/dt~ 10-8 s-2, R~106 cm, σ~1029 s-1 and we get a magnetic field of the order of 1010 G.

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