Comparison of the Dosimetric Characteristics of High Atomic-numbered Inorganic Scintillators as a Fiber Optic-based Photon Dosimeter

다국어 초록 (Multilingual Abstract)

A fiber optic-based scintillation detector has been constructed to investigate its applicability as a gamma ray dosimeter to be used in a <SUP>60</SUP>Co irradiation room. The detector is constructed by attaching a small cylindrical piece of scintillator on one end of a plastic optical fiber, while the other end is connected to a current-type PMT. The net PMT current is converted into dose rate through calibration with a Farmer type ionization chamber. Tests are conducted with 3 commercially available inorganic scintillators: BGO, CWO, and LYSO being used as the photon sensor to investigate a key dosimetric parameter in a <SUP>60</SUP>Co irradiation room. The dosimetric characteristic analyzed is linearity of the PMT current with respect to the dose rate. Current-to-dose rate conversion functions are obtained for the three scintillators based on their linearity values, and deviations are estimated. According to our investigation, the detector with the CWO shows the best linearity over the whole dose range considered, and the BGO the next. Overall deviation is within ±8% with the CWO, and ±10% with the BGO. The detector with the LYSO, though producing the largest PMT current, shows very poor linearity, especially in the low dose range.

참고문헌 (Reference)

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