scholarly journals Solar Eruptions and Energetic Particles: An Introduction

2006 ◽  
Keyword(s):  
Energetic Particles ◽  
Solar Eruptions

scholarly journals Sources of solar energetic particles

2019 ◽  
Vol 377 (2148) ◽  
pp. 20180095 ◽  
Author(s):  
Loukas Vlahos ◽  
Anastasios Anastasiadis ◽  
Athanasios Papaioannou ◽  
Athanasios Kouloumvakos ◽  
Heinz Isliker
Keyword(s):  
Solar Corona ◽  
Space Weather ◽  
Solar Flares ◽  
Large Scale ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Plasma Parameters ◽  
Current Sheets ◽  
Solar Eruptions ◽  
Magnetohydrodynamic Simulations

Solar energetic particles are an integral part of the physical processes related with space weather. We present a review for the acceleration mechanisms related to the explosive phenomena (flares and/or coronal mass ejections, CMEs) inside the solar corona. For more than 40 years, the main two-dimensional cartoon representing our understanding of the explosive phenomena inside the solar corona remained almost unchanged. The acceleration mechanisms related to solar flares and CMEs also remained unchanged and were part of the same cartoon. In this review, we revise the standard cartoon and present evidence from recent global magnetohydrodynamic simulations that support the argument that explosive phenomena will lead to the spontaneous formation of current sheets in different parts of the erupting magnetic structure. The evolution of the large-scale current sheets and their fragmentation will lead to strong turbulence and turbulent reconnection during solar flares and turbulent shocks. In other words, the acceleration mechanism in flares and CME-driven shocks may be the same, and their difference will be the overall magnetic topology, the ambient plasma parameters, and the duration of the unstable driver. This article is part of the theme issue ‘Solar eruptions and their space weather impact’.

scholarly journals Positron Processes in the Sun

Atoms ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 14 ◽  
Author(s):  
Nat Gopalswamy
Keyword(s):  
Gamma Ray ◽  
Impulsive Phase ◽  
Energetic Particles ◽  
Continuum Emission ◽  
The Sun ◽  
Extended Phase ◽  
Solar Eruptions ◽  
Low Energies ◽  
Shock Mechanism ◽  
Recent Developments

Positrons play a major role in the emission of solar gamma-rays at energies from a few hundred keV to >1 GeV. Although the processes leading to positron production in the solar atmosphere are well known, the origin of the underlying energetic particles that interact with the ambient particles is poorly understood. With the aim of understanding the full gamma-ray spectrum of the Sun, I review the key emission mechanisms that contribute to the observed gamma-ray spectrum, focusing on the ones involving positrons. In particular, I review the processes involved in the 0.511 MeV positron annihilation line and the positronium continuum emissions at low energies, and the pion continuum emission at high energies in solar eruptions. It is thought that particles accelerated at the flare reconnection and at the shock driven by coronal mass ejections are responsible for the observed gamma-ray features. Based on some recent developments I suggest that energetic particles from both mechanisms may contribute to the observed gamma-ray spectrum in the impulsive phase, while the shock mechanism is responsible for the extended phase.

Role of energetic particles in heat and particle exhaust in a poloidal divertor RFP

1997 ◽  
Vol 241-243 (1) ◽  
pp. 1002-1007 ◽  
Author(s):  
S Masamune
Keyword(s):  
Energetic Particles

Assessing the Predictability of Solar Energetic Particles with the Use of Machine Learning Techniques

Solar Physics ◽  
2021 ◽  
Vol 296 (7) ◽  
Author(s):  
E. Lavasa ◽  
G. Giannopoulos ◽  
A. Papaioannou ◽  
A. Anastasiadis ◽  
I. A. Daglis ◽  
...  
Keyword(s):  
Machine Learning ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Machine Learning Techniques ◽  
Learning Techniques

scholarly journals Precession drift reversal and rapid transport of trapped energetic particles due to an energetic particle driven instability in the Large Helical Device

2021 ◽  
Vol 28 (8) ◽  
pp. 080701
Author(s):  
M. Idouakass ◽  
Y. Todo ◽  
H. Wang ◽  
J. Wang ◽  
R. Seki ◽  
...  
Keyword(s):  
Energetic Particle ◽  
Energetic Particles ◽  
Rapid Transport

scholarly journals On particle acceleration and transport in plasmas in the Galaxy: theory and observations

2021 ◽  
Vol 87 (1) ◽  
Author(s):  
Elena Amato ◽  
Sabrina Casanova
Keyword(s):  
Particle Acceleration ◽  
Cosmic Rays ◽  
Galactic Cosmic Rays ◽  
Energetic Particles ◽  
Quality Data ◽  
Current Status ◽  
The Earth ◽  
The Galaxy ◽  
Formation And Evolution ◽  
Galaxy Assembly

Accelerated particles are ubiquitous in the Cosmos and play a fundamental role in many processes governing the evolution of the Universe at all scales, from the sub-AU scale relevant for the formation and evolution of stars and planets to the Mpc scale involved in Galaxy assembly. We reveal the presence of energetic particles in many classes of astrophysical sources thanks to their production of non-thermal radiation, and we detect them directly at the Earth as cosmic rays. In the last two decades both direct and indirect observations have provided us a wealth of new, high-quality data about cosmic rays and their interactions both in sources and during propagation, in the Galaxy and in the Solar System. Some of the new data have confirmed existing theories about particle acceleration and propagation and their interplay with the environment in which they occur. Some others have brought about interesting surprises, whose interpretation is not straightforward within the standard framework and may require a change of paradigm in terms of our ideas about the origin of cosmic rays of different species or in different energy ranges. In this article, we focus on cosmic rays of galactic origin, namely with energies below a few petaelectronvolts, where a steepening is observed in the spectrum of energetic particles detected at the Earth. We review the recent observational findings and the current status of the theory about the origin and propagation of galactic cosmic rays.

scholarly journals Analysis of Alfven eigenmodes destabilization by energetic particles in TJ-II using a Landau-closure model

2017 ◽  
Vol 57 (12) ◽  
pp. 126019 ◽  
Author(s):  
J. Varela ◽  
D.A. Spong ◽  
L. Garcia
Keyword(s):  
Energetic Particles ◽  
Closure Model ◽  
Alfven Eigenmodes

Atom & cosmos: Plasma corkscrews produce new twist: Latest observation extends debate over solar eruptions

Science News ◽  
2014 ◽  
Vol 186 (7) ◽  
pp. 9-9
Author(s):  
Thomas Sumner
Keyword(s):  
Solar Eruptions
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