Noise contributions to energy resolution in CsI(Tl) scintillation detector with PIN photodiode readout

The different noise contributions to the energy resolution of a CsI(Tl)-photodiode gamma detector have been measured. A “light noise” originating from the crystal has been detected. It has been found that it could be the main restricting factor together with the photodiode leakage current. Temperature dependence of the “light noise” is reported.