Balloon-borne observations of the galactic positron fraction during solar minimum negative polarity

[1] Galactic cosmic ray electrons and nuclei respond differently to solar modulation, with the differences directly related to the reversals of the solar magnetic field, which occur every 11 years. If the large-scale heliospheric magnetic field has certain types of structures, the charge sign of cosmic ray particles can affect their propagation. Careful study of the behavior of cosmic ray positrons, relative to negative electrons (which have identical masses), allows for a definitive separation of the effects due to charge sign from the other possible effects. As part of an ongoing investigation of charge sign dependence in solar modulation, cosmic ray positron fraction in the energy range of 0.6 to 4.5 GeV was measured on a balloon flight from Kiruna, Sweden, to Victoria Island, Canada, during 2–6 June 2006. Measurements from this flight are compared to previous results and current models.