Temperature effects on MIPs in the BGO calorimeters of DAMPE

Abstract

In this paper, we presented a study of temperature effects on BGO calorimeters using proton MIP's collected in the first year operation of DAMPE. By directly comparing MIP calibration constants used by DAMPE data production pipe line, we found an experimental relation between temperature and signal amplitudes of each BGO bar: a general deviation of -1.162%/$^{\circ}$C,and -0.47%/$^{\circ}$C to -1.60%/$^{\circ}$C statistically for each detector element. During 2016, DAMPE's temperature changed by about 7 degrees due to solar elevation angle and the corresponding energy scale bias is about 8%. By frequent MIP calibration operation, this kind of bias is eliminated to an acceptable value.