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Ion acceleration in impulsive solar flaresNonrelativistic spectra of protons and ions accelerated in impulsive solar flares are derived using more realistic turbulence power spectra. The calculation is based on a particle transport equation extracted from a second step acceleration model containing stochastic acceleration. The turbulence model is generalized to waves with a small angle to the magnetic field vector and to turbulence power spectra with spectral indices s smaller than 2. Due to the occurrence of impulsive flares at low coronal heights, Coulomb losses at the dense coronal plasma and diffusive particle escape are taken into account. The ion spectra show deviations from long-duration spectra near the Coulomb barrier, where the losses become maximal. The Z-squared/A-dependence of the Coulomb losses leads to spectral variations for different ions. We present a method to estimate the turbulence parameters and injection conditions of the flare particles using ion ratios like Fe/O of impulsive flares.
Document ID
19930072483
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Steinacker, Jurgen
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Jaekel, Uwe
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Schlickeiser, Reinhard
(Max-Planck-Inst. fuer Radioastronomie Bonn, Germany)
Date Acquired
August 16, 2013
Publication Date
September 20, 1993
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 415
Issue: 1
ISSN: 0004-637X
Subject Category
Solar Physics
Accession Number
93A56480
Funding Number(s)
CONTRACT_GRANT: DFG-SCHL-201/8-1
Distribution Limits
Public
Copyright
Other

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