Equalization for the low-response cells of the AMS-02 electromagnetic calorimeter

PurposePerforming precision equalization on the low-response detection units of electromagnetic calorimeter (ECAL), it is essential for precision energy measurements of Alpha Magnetic Spectrometer (AMS-02). MethodsCosmic helium nuclei are used instead of protons to perform the equalization. During the equalization, temperature effects are analyzed and corrected to improve the accuracy. ResultsThe results of helium equalization are consistent with proton equalization, and the precision of helium equalization is about 1.5%. ConclusionsThe precision of helium equalization is better than that of proton equalization, which provides a reliable alternative to ECAL on-orbit equalization.