Measurement of the positron fraction in cosmic rays from 0.5-350 GeV with the AMS-02 detector on the International Space Station

The Alpha Magnetic Spectrometer (AMS-02) is a state of the art particle detector mounted on the International Space Station. Redundant particle identification with five subdetectors allows to precisely measure the cosmic ray spectra up to TeV energies. In this work a new alignment and track reconstruction method for the Transition Radiation Detector (TRD) of AMS-02 are introduced and the measurement of the positron fraction in cosmic rays with the first 18 month of AMS-02 data is presented.