The isotopic composition and fluence of solar-wind nitrogen in a genesis B/C array collector
Abstract
We have measured the isotopic composition and fluence of solar-wind nitrogen in a diamond-like-carbon collector from the Genesis B/C array. The B and C collector arrays on the Genesis spacecraft passively collected bulk solar wind for the entire collection period, and there is no need to correct data for instrumental fractionation during collection, unlike data from the Genesis "Concentrator." This work validates isotopic measurements from the concentrator by Marty et al. (2010, 2011); nitrogen in the solar wind is depleted in ^(15)N relative to nitrogen in the Earth's atmosphere. Specifically, our array data yield values for ^(15)N/^(14)N of (2.17 ± 0.37) × 10^(−3) and (2.12 ± 0.34) × 10^(−3), depending on data-reduction technique. This result contradicts preliminary results reported for previous measurements on B/C array materials by Pepin et al. (2009), so the discrepancy between Marty et al. (2010, 2011) and Pepin et al. (2009) was not due to fractionation of solar wind by the concentrator. Our measured value of ^(15)N/^(14)N in the solar wind shows that the Sun, and by extension the solar nebula, lie at the low-^(15)N/^(14)N end of the range of nitrogen isotopic compositions observed in the solar system. A global process (or combination of processes) must have operated in interstellar space and/or during the earliest stages of solar system formation to increase the ^(15)N/^(14)N ratio of the solar system solids. We also report a preliminary Genesis solar-wind nitrogen fluence of (2.57 ± 0.42) × 10^(12) cm^(−2). This value is higher than that derived by backside profiling of a Genesis silicon collector (Heber et al. 2011a).
Additional Information
© 2012 Meteoritical Society. Received 06 April 2011; revision accepted 22 July 2012. Article first published online: 14 Sep. 2012. Editorial Handling—Dr. Ian Franchi. This paper benefited from helpful reviews by Veronika Heber, Andrew Davis, and Bernard Marty. It was supported by NASA grant NNX09AC32G to GRH and NNX09AC35G to DSB. This is Hawai'i Institute of Geophysics and Planetology publication No. 1977 and School of Ocean and Earth Science and Technology publication No. 8696. Los Alamos National Laboratory publication LA-UR-12-24206.Attached Files
Published - j.1945-5100.2012.01406.x.pdf
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Additional details
- Eprint ID
- 35462
- Resolver ID
- CaltechAUTHORS:20121114-120747648
- NNX09AC32G
- NASA
- NNX09AC35G
- NASA
- Created
-
2012-11-14Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences
- Other Numbering System Name
- Los Alamos National Laboratory
- Other Numbering System Identifier
- LA-UR-12-24206