Abstract
This paper presents the design and evaluation of a portable γ spectrometer with an automatic constant temperature function. The γ spectrometer includes a detector consisting of a CsI(Na) crystal coupled with a silicon photomultiplier (SiPM) array and highly integrated readout electronics. The performance of the crystal and SiPM changes with temperature. To solve this problem, we design a thermoelectric cooler-based unit to keep the temperature constant. Experiments are conducted to evaluate the performance of the γ spectrometer under different temperatures. The test results show that when the external temperature range is 2–38 °C, the temperature inside the spectrometer remains constant at 20 ± 0.07 °C. Because of the constant temperature, the peak drift for 662 keV is reduced to 1.80 channels, and the energy resolution for 662 keV remains around 8.20%.