AMS-02 measurement of cosmic ray positrons and electrons

Precision measurements by AMS of the primary cosmic-ray positron fraction and the positron flux in the energy range 0.5 to 500 GeV, and the electron flux in the range 0.5 to 700 GeV are presented. The results show that above 200 GeV the positron fraction no longer exhibits an increase with energy. The positron flux and the electron flux are significantly different in their magnitude and energy dependence. They each require a description beyond a single power-law spectrum. Between 20 and 200 GeV the positron spectral index is significantly harder than the electron spectral index. The incoming direction of primary CR positrons and electrons are found to be consistent with isotropy within the current accuracy.