Ultra-high resolution of radiocesium distribution detection based on Cherenkov light imaging

チェレンコフ光イメージング技術による放射性セシウム分布の超高分解能撮像

山本 誠一*; 緒方 良至*; 河地 有木; 鈴井 伸郎; 尹 永根; 藤巻 秀

Yamamoto, Seiichi*; Ogata, Yoshimune*; Kawachi, Naoki; Suzui, Nobuo; Yin, Y.-G.; Fujimaki, Shu

After the nuclear disaster in Fukushima, radiocesium contamination became a serious scientific concern and research of its effects on plants increased. In such plant studies, high resolution images of radiocesium are required without contacting the subjects. Cherenkov light imaging of beta radionuclides has inherently high resolution and is promising for plant research. Since Cs and Cs emit beta particles, Cherenkov light imaging will be useful for the imaging of radiocesium distribution. Consequently, we developed and tested a Cherenkov light imaging system. We used a high sensitivity cooled charge coupled device (CCD) camera for imaging Cherenkov light from Cs and Cs. A bright lens was mounted on the camera and placed in a black box. With a 100-m Cs point source, we obtained 220-m spatial resolution in the Cherenkov light image. With a 1-mm diameter, 320-kBq Cs point source, the source was distinguished within 2-s. We successfully obtained Cherenkov light images of a plant whose root was dipped in a Cs solution, radiocesium-containing samples as well as line and character phantom images with our imaging system. Cherenkov light imaging is promising for the high resolution imaging of radiocesium distribution without contacting the subject.