Performance of a liquid argon electromagnetic calorimeter with an “accordion” geometry

Abstract The first prototype of a lead—liquid-argon e.m. calorimeter with accordion-shaped absorber and electrode plates has been built and tested with electron and muon beams at the CERN SPS. This novel geometry combines good granularity with high readout speed and minimal dead space. For a response peaking time of 140 ns, an energy resolution of 10%/ E[ GeV ] and a space resolution of 4.4 mm/ E[ GeV ] with a 2.7 cm cell size have been achieved for electrons. The position accuracy for muons is better than 2 mm.