A High Resolution BGO Calorimeter with Longitudinal Segmentation

Abstract We report on the construction and test results of a 8 × 8 module electromagnetic BGO calorimeter with both longitudinally non-segmented modules and modules with longitudinal segmentation for improved electron/hadron discrimination and two shower separation. The data have been taken mainly at the CERN PS accelerator at electron and pion momenta ranging from 0.5–6 GeV/ c . The crystals are read out via large area silicon PIN photodiodes coupled to specially developed low-noise preamplifiers and pulse-processor modules with automatic gain range selection. We discuss the energy and position resolution as well as the performance for particle identification and two shower separation.