High Energy Particles in Solar Flares: Observations, Mechanisms and Transport

MacKinnon, A. (2014) High Energy Particles in Solar Flares: Observations, Mechanisms and Transport. In: 40th COSPAR Scientific Assembly, Moscow, Russia, 2-10 Aug 2014,

Abstract

We review the observations bearing on electron and ion acceleration in solar flares, and the key challenges they pose to theory. Solar flare hard X-rays testify to the presence of accelerated electrons, with energies extending from thermal to the MeV range and possibly beyond. A variety of line and continuum signatures in the gamma-ray range reveal properties of energetic ions, from MeV to GeV energies. We review the ideas of the thick target and local reacceleration models for source regions and their implications for overall pictures of the flare energy release. Attainment of the highest particle energies poses a different sort of challenge to theory. Using the nuclear transport code FLUKA we show examples of the transport and radiation of ~GeV energy ions and their secondaries, and consider some of the questions raised by long-lasting high-energy continuum after flares. The further constraints offered by radio and sub-mm observations are discussed, sub-mm in particular both posing new questions and offering new insights. We conclude by identifying a few key questions for future flare studies.

• Item Type: Conference Proceedings
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: MacKinnon, Dr Alexander
• Authors: MacKinnon, A.
• College/School: College of Science and Engineering > School of Physics and Astronomy