Temperature gain correction for CsI(Tl) detection systems based on digital pulse shape analysis

In this paper we propose a pulse shape based method for monitoring the interior temperature of a CsI(Tl) crystal in order to correct the temperature dependence in the energy calibration of the corresponding detector system. The gain dependence on temperature of the CsI(Tl) detector was measured using both, a photomultiplier tube (PMT) and an avalanche photodiode (APD) readout photosensor. The analysis shows that the gain shifts due to temperature variations can be corrected to a precision of better than 1% with both the PMT and the APD, well below the CsI(Tl) intrinsic energy resolution for ~1 MeV γ-rays.