LAUSR

BackgroundThe electromagnetic calorimeter (ECAL) of the Alpha Magnetic Spectrometer (AMS-02) measures the energy of electrons/positrons and separates them from protons. Currently, there are five dead cells in the ECAL which affect the reconstructed energy of particles. The particle identification power of the ECAL decreases when particles pass through these dead cells or close to the ECAL border.PurposeTo improve the ECAL particle identification for particles pass through these dead cells or close to the ECAL border.MethodsAn improved ECAL particle identification estimator using the electromagnetic shower shape is developed with dead cell and side leakage corrections.ResultsFor events passing through dead cells, with this new estimator, the proton rejection power is improved by a factor of 2.2 and positron purity is improved from 31 to 50% in the energy range of 500–800 GeV.ConclusionThe new estimator works well for event passing through dead cells or close to the ECAL border.