Performance of the HEAT spectrometer for cosmic ray electrons and positrons

A new detector system for observations of cosmic ray electrons and positrons has been flown on a high altitude balloon in May 1994. The instrumentation includes a superconducting magnet and a drift tube hodoscope for the measurement of particle rigidities, and a combination of transition radiation detectors, shower counters and a time-of-flight system for particle identification and energy measurement. We will discuss the performance of the individual components and demonstrate that a reliable identification of the rare positron component has been achieved up to 50 GeV.