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Revised Production Rates for Na-22 and Mn-54 in Meteorites Using Cross Sections Measured for Neutron-induced ReactionsThe interactions of galactic cosmic rays (GCR) with extraterrestrial bodies produce small amounts of radionuclides and stable isotopes. The production rates of many relatively short-lived radionuclides, including 2.6-year Na-22 and 312-day Mn-54, have been measured in several meteorites collected very soon after they fell. Theoretical models used to calculate production rates for comparison with the measured values rely on input data containing good cross section measurements for all relevant reactions. Most GCR particles are protons, but secondary neutrons make most cosmogenic nuclides. Calculated production rates using only cross sections for proton-induced reactions do not agree well with measurements. One possible explanation is that the contribution to the production rate from reactions initiated by secondary neutrons produced in primary GCR interactions should be included explicitly. This, however, is difficult to do because so few of the relevant cross sections for neutron-induced reactions have been measured.
Document ID
20040062402
Acquisition Source
Johnson Space Center
Document Type
Conference Paper
Authors
Sisterson, J. M.
(Massachusetts General Hospital Boston, MA, United States)
Kim, K. J.
(New Mexico Univ. Albuquerque, NM, United States)
Reedy, R. C.
(New Mexico Univ. Albuquerque, NM, United States)
Date Acquired
August 21, 2013
Publication Date
January 1, 2004
Publication Information
Publication: Lunar and Planetary Science XXXV: Isotopes in Meteorites
Subject Category
Astrophysics
Funding Number(s)
CONTRACT_GRANT: W-7405-eng-36
CONTRACT_GRANT: NAG5-12918
CONTRACT_GRANT: NAG5-10538
Distribution Limits
Public
Copyright
Public Use Permitted.
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