Development of a SiPM-based CsI(Tl) spectrometer with gain stabilization designs for rapid temperature variations

A spectrometer employing a silicon photomultiplier (SiPM) based scintillation detector has spectrum drift issues under temperature variations. Although some temperature-dependent compensation methods are reported, spectrum distortions under rapid temperature fluctuations have received little attention. We have developed a SiPM-based CsI(Tl) spectrometer and proposed gain stabilization designs to settle this problem. A temperature sensor was coupled to the SiPM in the detector and wrapped with a thermal insulation foam material to acquire the temperature of the SiPM. Meanwhile, a temperature correction module was applied in the field-programmable gate array (FPGA) within a custom multichannel analyzer (MCA). The effectiveness of the temperature correction module in the FPGA and a specialized detector design were studied and verified under slow and rapid temperature variations. The results prove that the spectrum drifts of the SiPM-based CsI(Tl) spectrometer under rapid temperature variations can be significantly constrained with the proposed gain stabilization designs.