5×5 mm2 granular electromagnetic calorimeter using 45 × 5 mm2 scintillator strips and SiPMs

The CALICE collaboration is developing a fine granular electromagnetic calorimeter using 45 × 5 mm2 strips for application of the particle flow approach in future linear collider experiments. After developing a 30-layer prototype that achieved high-energy resolution for single-particle events, a more realistic prototype to be implemented in the real linear collider detector has been developed: readout boards that are embedded between layers were fabricated and tested with 3GeV electron beams, demonstrating the effective 5×5 mm2 granularity. Each readout board has an area of 180 × 180 mm2, consisting of 144 channels of scintillator strips coupled with SiPMs read out using four ASICs. The performance of an algorithm that can extract the effective 5×5 mm2 granularity from the 45 × 5 mm2 strips is also described.