A measurement of the cosmic ray positron fraction e+/(e++e−)e+/(e++e−) in the energy range of 1–30 GeV is presented. The measurement is based on data taken by the AMS-01 experiment during its 10 day Space Shuttle flight in June 1998. A proton background suppression on the order of 106 is reached by identifying converted bremsstrahlung photons emitted from positrons

No abstract

The primary proton spectrum in the kinetic energy range 0.2 to 200 GeV was measured by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS–91 at an altitude of 380 km. The complete data set combining three shuttle attitudes and including all known systematic effects is presented

No abstract

The proton spectrum in the kinetic energy range 0.1 to 200 GeV was measured by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS-91 at an altitude of 380 km. Above the geomagnetic cutoff the observed spectrum is parameterized by a power law. Below the geomagnetic cutoff a substantial second spectrum was observed concentrated at equatorial latitudes with a flux ~ 70 m^-2 sec^-1 sr^-1. Most of these second spectrum protons follow a complicated trajectory and originate from a restricted geographic region.Comment: 19 pages, Latex, 7 .eps figure