Development of a Ce:GPS scintillator-based spectrometer and its demonstration in radioactive cesium contamination sites

Morishita, Yuki   ; Nakama, Shigeo ; Ochi, Kotaro   ; Urabe, Yoshimi*; Kanno, Marina*

Following the Fukushima Daiichi Nuclear Power Plant accident, radioactive cesium contamination posed a significant environmental concern. This study developed a compact gamma-ray spectrometer utilizing a Ce:GPS scintillator and a compact photomultiplier tube (PMT) for environmental monitoring. The spectrometer was designed to overcome limitations of traditional NaI(Tl) detectors, leveraging the non-hygroscopic nature and high energy resolution of Ce:GPS scintillators. Performance was evaluated through measurements of a Cs source and comparison with a commercial NaI(Tl) survey meter. The spectrometer's potential for effective and portable monitoring of radioactive cesium in contaminated environments was demonstrated. The system was tested using sealed sources, confirming its ability to detect the 662 keV photopeak of Cs with high accuracy. Field measurements in radiocesium-contaminated areas showed the spectrometer's effectiveness in detecting dose rate variations and high-dose hotspots. This portable, durable spectrometer shows promise for applications in environmental radiation monitoring and remote sensing technologies.