NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
The energy spectra of solar flare hydrogen, helium, oxygen, and iron - Evidence for stochastic accelerationThe time-integrated differential energy spectra of H, He, O, and Fe measured in 10 large flare events observed at 1 AU over the energy range of 0.3-80 MeV/nucleon showed consistent patterns in their spectral shapes: particles with larger mean mass-to-charge ratios were generally less abundant at higher energies. A steady state model of stochastic particle acceleration with rigidity-dependent diffusion coefficients fit the spectra best; spectra representative of diffusive shock acceleration also described the spectra of some events with the same number of free parameters, but often fell off faster in energy above 30 MeV per nucleon than the observations. The two model predictions differed most at energies near 0.1 MeV per nucleon, below the lowest energies observed in this study. The stochastic model quantitatively described the observed spectral ordering with less efficient acceleration of species with larger mean mass-to-charge ratios.
Document ID
19930035801
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Mazur, J. E.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Mason, G. M.
(Maryland Univ. College Park, United States)
Klecker, B.
(Max-Planck-Inst. fuer Extraterrestrische Physik Garching, Germany)
Mcguire, R. E.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 15, 2013
Publication Date
December 10, 1992
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 401
Issue: 1
ISSN: 0004-637X
Subject Category
Solar Physics
Accession Number
93A19798
Funding Number(s)
CONTRACT_GRANT: NSF ATM-90-23414
CONTRACT_GRANT: NAGW-1990
CONTRACT_GRANT: NAG5-728
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available