Position resolution and electron identification with prototypes of the ALICE TRD

A Transition Radiation Detector (TRD) has been designed to improve the electron identification and trigger capability of the ALICE experiment at the CERN Large Hadron Collider. Especially at the trigger level, excellent performance is required in terms of pion rejection and tracking. Four identical TRD prototypes were tested at the secondary mixed electron/pion beam facility at the CERN PS over a momentum range from 1 to 6 GeV/c. We present measurements of position and angular resolution, the measured momentum dependence of the pion efficiency, and comparisons to simulations.