Three-dimensional localization and radioactivity quantification of radiation sources through inverse estimation based on Compton camera measurements

コンプトンカメラ測定を基盤とした逆推定による放射線源の3次元位置特定と放射能定量

佐藤 優樹  

Sato, Yuki

Radioactive substances released during the Fukushima Daiichi Nuclear Power Station accident were deposited on various equipment and building structures within the plant site. To minimize worker exposure and plan effective remediation strategies, accurately identifying the locations of these deposits is crucial. In response to this need, the current study presents a method to accurately determine the locations of multiple radiation sources in three dimensions and quantify their radioactivity levels. In particular, the method involves the application of an inverse estimation technique to data captured using a Compton camera. Here, the target region is first divided into multiple regions of interest. Image data are then acquired by placing a radiation source of known radioactivity in each region of interest. The resulting images are subsequently multiplied by each coefficient and summed to reproduce the image data of multiple unknown radiation sources. The radioactivity of each unknown radiation source is then derived based on the coefficients determined through inverse estimation.