Energy Release and Particle Acceleration in Solar Flares with Respect to Flaring Magnetic Loops

1998 ◽  
pp. 273-284 ◽  
Author(s):  
T. Sakao ◽  
T. Kosugi ◽  
S. Masuda
Keyword(s):  
Particle Acceleration ◽  
Energy Release ◽  
Solar Flares

scholarly journals Particle Acceleration in Solar Flares and Coronal Mass Ejections

2000 ◽  
Vol 195 ◽  
pp. 15-25
Author(s):  
R. P. Lin
Keyword(s):  
Particle Acceleration ◽  
Energy Release ◽  
Coronal Mass Ejections ◽  
Solar Flares ◽  
Gamma Ray ◽  
Solar Energetic Particle ◽  
High Energy ◽  
Total Rate ◽  
Solar Energetic Particle Events ◽  
High Energy Particles

The Sun accelerates ions up to tens of GeV and electrons up to 100s of MeV in solar flares and coronal mass ejections. The energy in the accelerated tens-of-keV electrons and possibly ~1 MeV ions constitutes a significant fraction of the total energy released in a flare, implying that the particle acceleration and flare energy release mechanisms are intimately related. The total rate of energy release in transients from flares down to microflares/nanoflares may be significant for heating the active solar corona.Shock waves driven by fast CMEs appear to accelerate the high-energy particles in large solar energetic particle events detected at 1 AU. Smaller SEP events are dominated by ~1 to tens-of-keV electrons, with low fluxes of up to a few MeV/nucleon ions, typically enriched in 3He. The acceleration in gamma-ray flares appears to resemble that in these small electron-3He SEP events.

Observations of Energetic Electrons in Solar Flares

1990 ◽  
Vol 142 ◽  
pp. 438-438
Author(s):  
B. Lokanadham
Keyword(s):  
Particle Acceleration ◽  
Energy Release ◽  
Observational Data ◽  
Solar Flares ◽  
Energetic Electrons ◽  
X Ray

A study of the simultaneous observations of solar flares in optical, radio and X-ray bands is important in understanding the process of energy release and particle acceleration in the explosive phenomena of solar flares. In order to determine the characteristics of such energetic electrons in solar flares, a total number of 50 two-ribbon flares have been carefully selected during the period 1979-89 having simultaneous observational data in the optical, X-ray and radio bands.

scholarly journals Particle Acceleration and Plasma Heating at Collisionless Shocks in Solar Flares

1989 ◽  
Vol 104 (2) ◽  
pp. 325-328
Author(s):  
Peter J. Cargill ◽  
Loukas Vlahos
Keyword(s):  
Particle Acceleration ◽  
Energy Release ◽  
Solar Flares ◽  
Plasma Heating ◽  
Collisionless Shocks

AbstractRecent observations suggest that the energy release in solar flares may occur in many small bursts. If these bursts give rise to plasma heating, a large number of collisionless shocks will be generated. These shocks can individually heat plasma and accelerate particles, but the interaction of particles with many shocks as well, as of shocks with each other can give rise to further heating and acceleration.

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 The Role of Eruption in Solar Flares

1989 ◽  
Vol 104 (1) ◽  
pp. 387-397
Author(s):  
Peter A. Sturrock
Keyword(s):  
Energy Release ◽  
Solar Atmosphere ◽  
Coronal Mass Ejections ◽  
Solar Flares ◽  
Thought Experiments ◽  
Physical Behavior ◽  
Current Interruption ◽  
Flare Process ◽  
Plasma Configuration

AbstractThis article focuses on two problems involved in the development of models of solar flares. The first concerns the mechanism responsible for eruptions, such as erupting filaments or coronal mass ejections, that are sometimes involved in the flare process. The concept of ‘loss of equilibrium’ is considered and it is argued that the concept typically arises in thought-experiments that do not represent acceptable physical behavior of the solar atmosphere. It is proposed instead that such eruptions are probably caused by an instability of a plasma configuration. The instability may be purely MHD, or it may combine both MHD and resistive processes. The second problem concerns the mechanism of energy release of the impulsive (or gradual) phase. It is proposed that this phase of flares may be due to current interruption, as was originally proposed by Alfvén and Carlqvist. However, in order for this process to be viable, it seems necessary to change one's ideas about the heating and structure of the corona in ways that are outlined briefly.

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