Temperature effects on MIPs in the BGO calorimeters of DAMPE

TL;DR

This study investigates how temperature variations affect BGO calorimeter signals in DAMPE, quantifying the relation and demonstrating calibration methods to mitigate temperature-induced biases in energy measurements.

Contribution

It provides the first detailed experimental analysis of temperature effects on BGO calorimeters in DAMPE and proposes calibration procedures to correct for temperature-related biases.

Findings

Temperature causes a -1.162%/°C deviation in signal amplitudes.

Energy scale bias of about 8% due to 7°C temperature change in 2016.

Frequent calibration effectively eliminates temperature-induced bias.

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.