NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
The isotopes of neon in the galactic cosmic raysThe paper examines the results obtained by the University of Chicago instrument on board the IMP 7 satellite used to measure the abundances of Ne-20 and Ne-22 in the galactic cosmic rays during 1973-1977, over the general energy range of 60-230 MeV per nucleon. It is reported that the instrument shows a mass resolution of 0.7 amu(sigma) which was confirmed by calibrating a backup instrument at the LBL Bevalac with separated beams of neon isotopes. Through the use of standard solar modulation and cosmic-ray propagation models, the cosmic-ray source ratio inferred is Ne-22/Ne-20 = 0.38 = or -0.07 which is significantly greater than the present solar system ratio. It is concluded that propagation effects or cross-section uncertainties cannot account for such a large abundance of Ne-22, and thus this measurement provides evidence that the cosmic rays come from a source region where the Ne-22 abundance is substantially greater than in solar system material.
Document ID
19790066822
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Garcia-Munoz, M.
(Chicago Univ. Chicago, IL, United States)
Simpson, J. A.
(Chicago Univ. Chicago, IL, United States)
Wefel, J. P.
(Chicago, University Chicago, Ill., United States)
Date Acquired
August 9, 2013
Publication Date
September 1, 1979
Publication Information
Publication: Astrophysical Journal
Subject Category
Space Radiation
Accession Number
79A50835
Funding Number(s)
CONTRACT_GRANT: NGL-14-001-006
CONTRACT_GRANT: NAS5-11067
Distribution Limits
Public
Copyright
Other

Available Downloads

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