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Cross sections from 5 to 35 MeV for the reactions nat Mg( 3 He,x) 26 Al, 27 Al( 3 He,x) 26 Al, nat Ca( 3 He,x) 41 Ca, and nat Ca( 3 He,x) 36 Cl: Implications for early irradiation in the solar system
Author(s) -
HERZOG Gregory F.,
CAFFEE Marc W.,
FAESTERMANN Thomas,
HERTENBERGER R.,
KORSCHINEK Gunther,
LEYA Ingo,
REEDY Robert C.,
SISTERSON J. M.
Publication year - 2011
Publication title -
meteoritics and planetary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.09
H-Index - 100
eISSN - 1945-5100
pISSN - 1086-9379
DOI - 10.1111/j.1945-5100.2011.01236.x
Subject(s) - nuclear reaction , spectral line , analytical chemistry (journal) , physics , atomic physics , meteorite , chemistry , nuclear physics , chromatography , astronomy
– Cross sections were measured for the nuclear reactions nat Mg( 3 He,x) 26 Al, 27 Al( 3 He,x) 26 Al, nat Ca( 3 He,x) 41 Ca, and nat Ca( 3 He,x) 36 Cl in the energy region from approximately 5–35 MeV. The rates of these reactions are important for studies of early solar system irradiation scenarios. The 26 Al, 36 Cl, and 41 Ca were separated chemically, and the numbers of atoms produced in each reaction channel were measured using accelerator mass spectrometry (AMS). From these results, 26 cross sections were determined and compared with predictions of the TALYS code. Agreement is within 40% for most cross sections. Our measurements were used to model the production of 7 Be, 10 Be, 26 Al, and 41 Ca in the early solar system. For projectiles 1 H, 3 He, and 4 He, we assumed energy spectra of the general form E −α . For a wide range of parameterizations, the modeled ratios of 7 Be/Be and 10 Be/Be on the one hand and of 26 Al/ 27 Al and 41 Ca/Ca on the other are coupled because the excitation functions for the relevant nuclear reactions have similar shapes. Modeling of a closed system with the constraint that 10 Be/ 9 Be = 0.001 fails to reproduce simultaneously the range of 7 Be/ 9 Be, 26 Al/ 27 Al, and 41 Ca/Ca ratios inferred for the early solar system from studies of meteorites.