Fabrication of Fiber-optics Detector for Measuring Radioactive Waste

Abstract

In this study, an optical fiber detector was constructed by using a Ce:GAGG scintillator, optical fiber, and photomultiplier. The single crystal size of the scintillator was set to 3 × 3 × 20 mm after simulating the counting efficiency of gamma rays in the scintillator by using the MCNPX code. The constructed detector used the standard gamma ray sources 137 Cs and 133Ba to measure radiation and analyze the spectral characteristics of gamma rays. The resulting trend curve showed excellent linearity with an R-squared value of 0.99741, and the detector characteristics were found to vary 2% or less with distance based on comparison with the MCNPX value. Furthermore, the spectroscopic analysis of the gamma ray energy from the single-ray and mixed-ray sources showed that 137 Cs had its peak energy at 662 keV, and 133 Ba had at 356 keV. It seems that if the fiber-optics detector is used, working hours and exposure of worker can be reduced.