Performance of the ALICE photon spectrometer PHOS

We present in this paper the measured characteristics of a 64 lead-tungstate crystal array designed to detect high-energy photons and neutral mesons with the ALICE photon spectrometer PHOS. The array has been tested with electron and charged pion secondary beams delivered by the CERN PS and SPS synchrotrons. Photon energy and π0 invariant mass resolutions are presented. The PHOS particle identification performance for data simulated with the AliRoot package is studied.