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The Isotopic Composition of Anomalous Cosmic Ray Neon

Cummings, A. C. and Stone, E. C. and Webber, W. R. (1991) The Isotopic Composition of Anomalous Cosmic Ray Neon. In: Proceedings of the 22nd International Cosmic Ray Conference. Vol.3. Institute for Advanced Studies , Dublin, Ireland, pp. 362-364.

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We have used observations of neon in the energy interval 14.6 - 35.6 MeV /nuc from the cosmic-ray experiment on the Voyager 2 (V2) spacecraft during 1986-1988 to derive the ^(22)Ne/^(20)Ne ratio for the source material of the anomalous cosmic rays (ACRs). Because of the relatively small contamination from galactic cosmic-ray (CCR) neon during the time period selected, we have significantly improved the precision with which this ratio is known. We find that the derived ACR source ratio, ^(22)Ne/^(20)Ne = 0.077 +0.068/-0.043, is consistent with the composition of the solar wind (0.073) and meteoritic neon-A (0.12), but inconsistent with the galactic cosmic ray source (0.43). This finding places new limits on the possible source material of the anomalous component. If the anomalous component does derive from the inward flowing interstellar neutral gas, then the composition of the source of galactic cosmic rays differs from that of the very local interstellar medium (VLISM).

Item Type:Book Section
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URLURL TypeDescription
Cummings, A. C.0000-0002-3840-7696
Stone, E. C.0000-0002-2010-5462
Additional Information:© Dublin Institute for Advanced Studies. Provided by the NASA Astrophysics Data System. This work was supported in part by NASA under contract NAS7-918 and grant NAGW-1919.
Group:Space Radiation Laboratory
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Space Radiation Laboratory1991-12
Record Number:CaltechAUTHORS:20140924-095030514
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:49983
Deposited By: Deborah Miles
Deposited On:29 Sep 2014 16:19
Last Modified:20 Feb 2020 14:33

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