Basic study of one-dimensional optical fiber based radiation distribution sensing by wavelength spectroscopy

Terasaka, Yuta; Watanabe, Kenichi*; Uritani, Akira*; Hanai, Tetsuya*; Sato, Yuki; Torii, Tatsuo; Wakaida, Ikuo

no journal, , 

For the reduction of the external dose of workers in the process of Fukushima Daiichi Nuclear Power Station (1F) decommissioning and to propose an effective decontamination plan, it is necessary to grasp the distribution of locally existing hotspots. A one-dimensional radiation distribution measurement system applying time-of-flight method to scintillating optical fiber has been widely applied after the 1F accident, but in a high dose rate environment such as 1F reactor building, a pile-up of signal and chance-coincidence effect of a sensor is a problem. Therefore, as an integral-type measurement method that can avoid problems such as pile-up, we propose a reverse-estimation method which measures the wavelength spectrum at the fiber edge and estimates the incident position of radiation to the fiber using the fact that the attenuation length of light depends on the wavelength.

One-dimensional radiation distribution sensing method based on wavelength spectrum unfolding of optical fiber

Terasaka, Yuta; Watanabe, Kenichi*; Uritani, Akira*; Sato, Yuki; Torii, Tatsuo; Wakaida, Ikuo

no journal, , 

no abstracts in English

Development and verification of radiation distribution sensing method based on wavelength spectrum unfolding

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

no journal, , 

no abstracts in English

放射線強度分布測定装置、放射線強度分布測定方法

寺阪 祐太

瓜谷 章*; 渡辺 賢一*

JP, 2019-150991  Patent licensing information  Patent publication (In Japanese)

【課題】高線量率の測定対象に対しても、簡易な装置構成で放射線強度分布を測定する。 【解決手段】光ファイバー10の長さ(図中左右方向)方向における放射線の入射位置が検出される。γ線光子Gがこの光ファイバー10のある地点(入射地点P)に入射すると、蛍光F1、F2が発せられ、かつこれらが光ファイバー10中を伝搬する。この光ファイバー10が発する蛍光(可視光)のスペクトルを測定可能な分光器20が、光ファイバー10の一方(図中右側)の端部に設けられる。一定の時間範囲内で分光器20によって前記のスペクトル(波長スペクトル)を得るスペクトル取得工程が行われ、その後に、このスペクトルより放射線強度分布(放射線強度のX依存性)を算出する算出工程が行われる。