Gain vs Temperature Effects in Nal(Tl) Photomultiplier Scintillation Detectors Using 10 and 14 Stage Tubes

The manner in which the gain of a radiation transducer comprised of a 2" × 2" NaI(Tl) crystal, and either a 5-inch 10-stage or 2-inch 14-stage photomultiplier tube viewing a Cs137 source, varies with ambient temperature changes over the range of 0° C to 50° C has been investigated. Gain vs temperature response curves are presented and operating temperatures which minimize gain variations are delineated. A method is given for evaluating the magnitude of gain variations encountered from the curves.