Status and Performance of the ALICE/PHOS Electromagnetic Calorimeter

The PHOS is a high resolution electromagnetic calorimeter in the ALICE experiment at the LHC. The PHOS is dedicated for measurements of gammas and neutral mesons in a wide dynamic range with high energy and spatial resolutions. The PHOS is subdivided into 5 independent rectangular modules. The module is segmented into 3584 detection channels (64 × 56 matrix). Each channel consists of a 22 × 22 × 180 mm3 lead-tungstate crystal, coupled with 5 × 5 mm2 avalanche photo diode. The first PHOS module was assembled, commissioned and tested with 2 GeV/c electrons at CERN on the T10 PS secondary beam-line.