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Jurewicz AJG, Rieck KD, Hervig R, Burnett DS, Wadhwa M, Olinger CT, Wiens RC, Laming JM, Guan Y, Huss GR, Reisenfeld DB, Williams P. Magnesium isotopes of the bulk solar wind from Genesis diamond-like carbon films. Meteorit Planet Sci 2020; 55:352-375. [PMID: 32214784 PMCID: PMC7079557 DOI: 10.1111/maps.13439] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 12/10/2019] [Indexed: 06/10/2023]
Abstract
NASA's Genesis Mission returned solar wind (SW) to the Earth for analysis to derive the composition of the solar photosphere from solar material. SW analyses control the precision of the derived solar compositions, but their ultimate accuracy is limited by the theoretical or empirical models of fractionation due to SW formation. Mg isotopes are "ground truth" for these models since, except for CAIs, planetary materials have a uniform Mg isotopic composition (within ≤1‰) so any significant isotopic fractionation of SW Mg is primarily that of SW formation and subsequent acceleration through the corona. This study analyzed Mg isotopes in a bulk SW diamond-like carbon (DLC) film on silicon collector returned by the Genesis Mission. A novel data reduction technique was required to account for variable ion yield and instrumental mass fractionation (IMF) in the DLC. The resulting SW Mg fractionation relative to the DSM-3 laboratory standard was (-14.4‰, -30.2‰) ± (4.1‰, 5.5‰), where the uncertainty is 2ơ SE of the data combined with a 2.5‰ (total) error in the IMF determination. Two of the SW fractionation models considered generally agreed with our data. Their possible ramifications are discussed for O isotopes based on the CAI nebular composition of McKeegan et al. (2011).
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Affiliation(s)
- A. J. G. Jurewicz
- Center for Meteorite StudiesArizona State Universitym/c 6004TempeArizona85287USA
| | - K. D. Rieck
- New Mexico Consortium4200 West Jemez Road Suite 200Los AlamosNew Mexico87544USA
| | - R. Hervig
- School of Earth and Space ExplorationArizona State UniversityTempeArizona85287USA
| | - D. S. Burnett
- Department of Geology and Planetary SciencesCalifornia Institute of Technologym/c 100‐23PasadenaCalifornia91125USA
| | - M. Wadhwa
- School of Earth and Space ExplorationArizona State UniversityTempeArizona85287USA
| | - C. T. Olinger
- GET‐NSA, LLC, AU‐6219901 Germantown RdGermantownMaryland20875USA
| | - R. C. Wiens
- Los Alamos National Laboratory (Remote Sensing)ISR‐2, m/s C‐331Los AlamosNew Mexico87545USA
| | - J. M. Laming
- Naval Research LaboratorySpace Science DivisionCode 7684WashingtonDistrict of Columbia20375USA
| | - Y. Guan
- Geological and Planetary SciencesCalifornia Institute of Technologym/c 100‐10PasadenaCalifornia91125USA
| | - G. R. Huss
- Hawaii Institute of Geophysics and PlanetologyUniversity of Hawaii at Manoa1680 East‐West Road, Post 504HonoluluHawaii96822USA
| | - D. B. Reisenfeld
- Los Alamos National Laboratory ISR‐1Los AlamosNew Mexico87545USA
| | - P. Williams
- School of Molecular SciencesArizona State UniversityTempeArizona85287USA
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Laming JM, Heber VS, Burnett DS, Guan Y, Hervig R, Huss GR, Jurewicz AJG, Koeman-Shields EC, McKeegan KD, Nittler L, Reisenfeld DB, Rieck KD, Wang J, Wiens RC, Woolum DS. DETERMINING THE ELEMENTAL AND ISOTOPIC COMPOSITION OF THE PRESOLAR NEBULA FROM GENESIS DATA ANALYSIS: THE CASE OF OXYGEN. Astrophys J Lett 2017; 851:L12. [PMID: 29657703 PMCID: PMC5893144 DOI: 10.3847/2041-8213/aa9bf0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We compare element and isotopic fractionations measured in solar wind samples collected by NASA's Genesis mission with those predicted from models incorporating both the ponderomotive force in the chromosphere and conservation of the first adiabatic invariant in the low corona. Generally good agreement is found, suggesting that these factors are consistent with the process of solar wind fractionation. Based on bulk wind measurements, we also consider in more detail the isotopic and elemental abundances of O. We find mild support for an O abundance in the range 8.75 - 8.83, with a value as low as 8.69 disfavored. A stronger conclusion must await solar wind regime specific measurements from the Genesis samples.
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Affiliation(s)
- J Martin Laming
- Space Science Division, Naval Research Laboratory, Code 7684, Washington DC 20375
| | - V S Heber
- Dept. of Earth, Planetary & Space Sciences UCLA, Los Angeles CA 90095
| | - D S Burnett
- Div. of Geological & Planetary Sciences, Caltech, Pasadena CA 91125
| | - Y Guan
- Div. of Geological & Planetary Sciences, Caltech, Pasadena CA 91125
| | - R Hervig
- School of Earth & Space Exploration, Arizona State University, Tempe, AZ 85287
| | - G R Huss
- Hawaii Institute of Geophysics & Planetology, University of Hawaii at Manoa, 1680 East-West Road, Honolulu, HI 96822
| | - A J G Jurewicz
- School of Earth & Space Exploration, Arizona State University, Tempe, AZ 85287
| | - E C Koeman-Shields
- Hawaii Institute of Geophysics & Planetology, University of Hawaii at Manoa, 1680 East-West Road, Honolulu, HI 96822
| | - K D McKeegan
- Dept. of Earth, Planetary & Space Sciences UCLA, Los Angeles CA 90095
| | - L Nittler
- Department of Terrestrial Magnetism, Carnegie Institute of Washington, Washington DC 20015
| | - D B Reisenfeld
- Department of Physics, University of Montana, Missoula, MT 59812
| | - K D Rieck
- Space and Remote Sensing (ISR-2), LANL, Los Alamos NM 877545
| | - J Wang
- Department of Terrestrial Magnetism, Carnegie Institute of Washington, Washington DC 20015
| | - R C Wiens
- Space and Remote Sensing (ISR-2), LANL, Los Alamos NM 877545
| | - D S Woolum
- Department of Physics, CSUF, Fullerton CA 92831
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