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

Purpose Performing 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).Methods Cosmic helium nuclei are used instead of protons to perform the equalization.During the equalization,temperature effects are analyzed and corrected to improve the accuracy.Results The results of helium equalization are consistent with proton equalization,and the precision of helium equalization is about 1.5%.Conclusions The precision of helium equalization is better than that of proton equalization,which provides a reliable alternative to ECAL on-orbit equalization.