2011/03/11 by Takashi Minoshima, Satoshi Masuda, Yoshizumi Miyoshi +1 · 1 citation
Physics and Astronomy · #Acceleration #Astrophysics and Cosmic Phenomena #Coronal loop #Electron #Electron precipitation #Ionosphere and magnetosphere dynamics #Particle acceleration #Scattering #Solar and Space Plasma Dynamics #Solar energetic particles #Solar flare #astro-ph.SR #physics.plasm-ph
paper · pdf · doi:10.1088/0004-637x/732/2/111
18 pages, 6 figures, accepted by ApJ
arxiv created 2011/03/11 · openalex publication_date 2011/04/25 · arxiv updated 2015/05/27 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Using a model of particle acceleration and transport in solar flares, we investigate the height distribution of coronal electrons by focusing on the energy-dependent pitch-angle scattering. When pitch-angle scattering is not included, the peak heights of loop-top electrons are constant, regardless of their energy, owing to the continuous acceleration and compression of the electrons via shrinkage of magnetic loops. On the other hand, under pitch-angle scattering, the electron heights are energy-dependent: intermediate-energy electrons are at a higher altitude, whereas lower and higher energy electrons are at lower altitudes. This implies that the intermediate-energy electrons are inhibited from following the shrinking field lines to lower altitudes because pitch-angle scattering causes efficient precipitation of these electrons into the footpoint and their subsequent loss from the loop. This result is qualitatively consistent with the position of the above-the-loop-top hard X-ray (HXR) source that is located above coronal HXR loops emitted by lower energy electrons and microwaves emitted by higher energy electrons. Quantitative agreement with observations might be achieved by considering primary acceleration before the onset of loop shrinkage and additional pitch-angle scattering via wave–particle interactions.