Fulltext

Nickel Isotopic Composition and Nickel/Iron Ratio in the Solar Wind: Results from SOHO/CELIAS/MTOF

Karrer, R. ; Bochsler, P. ; Giammanco, C. ; Ipavich, F. ; Paquette, J. ; Wurz, P.

In: Space Science Reviews, 2007, vol. 130, no. 1-4, p. 317-321

Aggiungi alla tua lista
    Titre
    • Nickel Isotopic Composition and Nickel/Iron Ratio in the Solar Wind: Results from SOHO/CELIAS/MTOF
    Auteur
    • Karrer, R.. Physikalisches Institut, University of Bern, Bern, Switzerland
    • Bochsler, P.. Physikalisches Institut, University of Bern, Bern, Switzerland
    • Giammanco, C.. Physikalisches Institut, University of Bern, Bern, Switzerland
    • Ipavich, F.. Department of Physics, University of Maryland, College Park, MD, USA
    • Paquette, J.. Department of Physics, University of Maryland, College Park, MD, USA
    • Wurz, P.. Physikalisches Institut, University of Bern, Bern, Switzerland
    Type de document
    • Postprint
    Langue
    • Inglese
    Publié dans
    • Space Science Reviews, 2007, vol. 130, no. 1-4, p. 317-321. Springer Netherlands
    Autre version électronique
    Identifiant OAI-PMH
    • oai:doc.rero.ch:310319
    Summary
    Using the Mass Time-of-Flight Spectrometer (MTOF)—part of the Charge, Elements, Isotope Analysis System (CELIAS)—onboard the Solar Heliospheric Observatory (SOHO) spacecraft, we derive the nickel isotopic composition for the isotopes with mass 58, 60 and 62 in the solar wind. In addition we measure the elemental abundance ratio of nickel to iron. We use data accumulated during ten years of SOHO operation to get sufficiently high counting statistics and compare periods of different solar wind velocities. We compare our values with the meteoritic ratios, which are believed to be a reliable reference for the solar system and also for the solar outer convective zone, since neither element is volatile and no isotopic fractionation is expected in meteorites. Meteoritic isotopic abundances agree with the terrestrial values and can thus be considered to be a reliable reference for the solar isotopic composition. The measurements show that the solar wind elemental Ni/Fe-ratio and the isotopic composition of solar wind nickel are consistent with the meteoritic values. This supports the concept that low-FIP elements are fed without relative fractionation into the solar wind. Our result also confirms the absence of substantial isotopic fractionation processes for medium and heavy ions acting in the solar wind