光ファイバを用いた新方式片側読み出し型放射線分布測定法に関する基礎研究

Basic study on a novel single-end readout type radiation distribution sensing method using an optical fiber

寺阪 祐太   ; 渡辺 賢一*; 瓜谷 章*

Terasaka, Yuta; Watanabe, Kenichi*; Uritani, Akira*

We developed a novel single-end readout type position-sensitive optical fiber radiation sensor. This sensor measures the radiation intensity distribution along the fiber with light readout only from single end of the optical fiber. To estimate the radiation intensity distribution, we analyzed the wavelength spectrum output at single end of the fiber, which contains information about the transmission distance of light inside the fiber. Based on the unfolding of the wavelength spectrum, the radiation intensity distribution along the fiber could be estimated. The effects of wavelength channel selection and signal-to-noise ratio of the wavelength spectrum on radiation distribution estimation were evaluated. In addition, we performed that our optical fiber sensor could estimate the radiation intensity distribution under the dose rate of 3 Gy/h. The dose rate detection limit was estimated to be 21 mGy/h for the irradiation range of 20 cm.