Proton energy spectra at the sun in the solar cosmic-ray events on 1978 May 7 and 1984 February 16

Abstract

view Abstract Citations (28) References (14) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Proton Energy Spectra at the Sun in the Solar Cosmic-Ray Events on 1978 May 7 and 1984 February 16 Lockwood, J. A. ; Debrunner, H. ; Flueckiger, E. O. ; Graedel, H. Abstract The solar proton differential energy spectra at the sun as a function of rigidity have been deduced for the solar cosmic-ray events on May 7, 1978 and February 16, 1984. Proton data were used from the IMP spacecraft for energies from about 20-500 MeV and from the worldwide network of neutron monitors for energies greater than 500 MeV. Since these events were characterized by essentially scatter-free propagation in the interplanetary medium, the solar proton energy spectra observed at earth were extrapolated back to the sun to obtain the source spectra. It was found that the relative solar proton spectra at the sun varied with time. They could be fitted by dJ/dE = A x P exp -delta x exp (-P/P0), where delta is about 4-5 and P0 is not less than 5000 MV. These results are interpreted in terms of the diffusive coronal shock acceleration model of Ellison and Ramaty (1985), obtaining shock sizes of greater than about 10 to the 9th cm and shock compression ratios of 1.7-2.1. The solar energy spectra predicted by stochastic acceleration do not fit the relative proton energy spectra at the sun for the two events considered. Publication: The Astrophysical Journal Pub Date: May 1990 DOI: 10.1086/168763 Bibcode: 1990ApJ...355..287L Keywords: Energy Spectra; Solar Cosmic Rays; Solar Protons; Solar Spectra; Spaceborne Astronomy; Imp; Proton Energy; Solar Flares; Solar Physics; COSMIC RAYS: GENERAL; PARTICLE ACCELERATION; SUN: FLARES; SUN: PARTICLE EMISSION full text sources ADS |