Authors: H. Kucharek, F.I. Ipavich, R. Kallenbach, B. Klecker, H. Grrünwaldt, M.R. Aellig, and P. Bochsler
Reference: SOHO 8 Workshop Proceedings, page 5, 1999
Data from the high resolution Mass Time-of-Flight spectrometer MTOF and the Charge Time-of-Flight spectrometer (CTOF) on board SOHO have been analyzed for time periods in which coronal hole or non-coronal hole type plasma has been detected in order to investigate the abundance ratios of magnesium isotopes originating from these two different source regions of the solar wind in the context of isotope fractionation. As an indicator for slow solar wind and coronal hole associated solar wind the freeze-in temperature as well as the Fe/O ratio derived from the CTOF experiment onboard SOHO have been used. A dependence of the magnesium isotopic abundance ratios on the freeze-in temperature of O6+/O7+ as well as on the Fe/O ratio has been found which indicates a possible depletion on the heavier isotopes in the slow solar wind.