Title: Magnesium isotopes in the solar wind as observed with the MTOF sensor on the CELIAS experiment on board the SOHO spacecraft

Authors: Kucharek H., Ipavich F.M., Kallenbach R., Bochsler P., Hovestadt D., Grünwaldt H., Hilchenbach M., Axford W.I., Balsiger H., Bürgi A., Coplan M.A., Galvin A.B., Geiss J., Gloeckler G., Hsieh K.C., Klecker B., Lee M.A., Livi S., Managadze G.G., Marsch E., Möbius E., Neugebauer M., Reiche K.U., Scholer M., Verigin M.I., Wilken B., and Wurz P.

Reference: Proceedings of the 5^th SOHO Workshop, 17-20 June, 1997, Oslo, Norway, ESA SP-404 473 - 476, 1997.

Abstract:
In this paper we present first results of the abundance ratio of magnesium isotopes measured in the solar wind by using the data from the high resolution Mass Time-of-Flight spectrometer MTOF on board the Solar and Heliospheric Observatory SOHO. MTOF is part of the Charge Element and Isotope Analysis System CELIAS and is with its very high time- and mass resolution an excellent tool for isotope abundance measurements. >From the analysis of the data, we have found that the isotopic composition of magnesium in the solar wind agrees within the relative experimental error of less than ten percent with the terrestrial composition. We have obtained isotopic ratios for ²⁴Mg/²⁵Mg = 7.4 ± 0.6 and for ²⁴Mg/²⁶Mg = 7.1 ± 0.6. These values are consistent with the terrestrial values of ²⁴Mg/²⁵Mg = 7.90 and ²⁴Mg/²⁶Mg = 7.17.

Last Update: May 17, 2000, James Weygand