Experimental evaluation of novel 4 field of view gamma-ray imaging method

北山 佳治  ; 野上 光博*; 人見 啓太朗*

Kitayama, Yoshiharu; Nogami, Mitsuhiro*; Hitomi, Keitaro*

In the present study, we devised a new gamma-ray imaging technique (Three-Dimentional Shadow Method: TDSM) that uses three-dimensional shadows of gamma rays. This technique is based on the fact that the three-dimensional shading of gamma-ray flux, which is uniquely determined by the direction of gamma-ray irradiation, is generated by randomly arranging shields in space. In this study, we developed a new prototype gamma-ray imager (Coded Cube Camera for Gamma-ray: C3G) and performed 4 gamma-ray imaging experiments targeting a Cs source. C3G is a gamma-ray imager designed to apply TDSM, consisting of 8 GAGG (Ce) scintillator cubes, 18 lead cubes, and one empty cube randomly arranged in a Rubik's cube configuration. The size of each cube is 10 mm 10 mm 10 mm; the entire C3G is 86 mm 86 mm 86 mm and weighs about 600 g. The experiments were conducted indoors and outdoors under the condition that the 10 MBq Cs source was placed at a 3 m from the C3G. As a result, it was experimentally confirmed that 4 imaging could be performed by the C3G with an angular resolution of approximately 10 degrees. This result suggests that the performance of our proposed method is equivalent to or better than that of the existing imaging methods. Further development of this technique is expected to significantly contribute to decommissioning, decontamination, nuclear medicine, astronomy, etc.