A Caltech Library Service

A high-resolution study of the isotopes of solar flare nuclei

Mewaldt, R. A. and Spalding, J. D. and Stone, E. C. (1984) A high-resolution study of the isotopes of solar flare nuclei. Astrophysical Journal, 280 (2). pp. 892-901. ISSN 0004-637X. doi:10.1086/162065.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


Individual isotopes of the elements He, C, N, O, Ne, and Mg with energies from ~5 to ~50 MeV per nucleon have been resolved in energetic solar flare particles during the 1978 September 23 solar flare event. These C, N, and O measurements are the first solar flare isotope measurements reported for these elements. In addition, we have improved on our earlier determination of ^(22)Ne/^(20)Ne in this flare by extending the energy interval for isotope analysis. We continue to find a significant difference between the isotopic composition of solar flare and solar wind neon, which we compare to similar evidence from studies of solar energetic particles implanted in lunar and meteoritic samples. Although limited by statistics, our measurements of He, C, N, O, and Mg isotopes are consistent with typical isotopic abundances found in other samples of solar system material. The ensemble of these results is used to test for the possibility of mass-dependent fractionation during solar flare acceleration and propagation. Finally, measurements of the elemental composition and energy spectra of this event allow us to interpret our isotope measurements within a broader context of solar flare composition studies.

Item Type:Article
Related URLs:
URLURL TypeDescription
Mewaldt, R. A.0000-0003-2178-9111
Stone, E. C.0000-0002-2010-5462
Additional Information:© 1984 American Astronomical Society. Received 1983 August 22; accepted 1983 November 22. We are grateful to R. E. Vogt for his contributions throughout the HIST program. We appreciate discussions with D. A. Leich on lunar neon measurements. This work was supported in part by NASA under contract NAS5-20721 and grant NGR 05-001-160.
Group:Space Radiation Laboratory
Funding AgencyGrant Number
NASANGR 05-001-160
Subject Keywords:cosmic rays: abundances, Sun: abundances, Sun: flares
Issue or Number:2
Record Number:CaltechAUTHORS:20140409-085626084
Persistent URL:
Official Citation:A high-resolution study of the isotopes of solar flare nuclei Mewaldt, R. A.; Spalding, J. D.; Stone, E. C. Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 280, May 15, 1984, p. 892-901.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:44806
Deposited By: Ruth Sustaita
Deposited On:09 Apr 2014 16:43
Last Modified:10 Nov 2021 16:56

Repository Staff Only: item control page