TUP129 　加速器応用・産業利用　 8月9日 コンベンションホール 13:10 - 15:10

社会インフラ水分検出用可搬型線形加速器駆動中性子源の開発

Development of Mobile Linac-driven Neutron Source for Moisture Inspection of Societal Infrastructures

○ベレデ ジャンミシェル（東大原子力国際），三津谷 有貴（東大原子力専攻），關 義親（JAEA J-PARCセンター），上坂 充（東大原子力専攻）

○Jean-michel Bereder (Department of Nuclear Engineering and Management , , Graduate School of Engineering, The University of Tokyo), Yuki Mitsuya (Nuclear Professional School, Graduate School of Engineering, The University of Tokyo), Yoshichika Seki (JAEA J-PARC Center), Mitsuru Uesaka (Nuclear Professional School, Graduate School of Engineering, The University of Tokyo)

The existing non-destructive inspection method using high energy X-ray for societal infrastructures is aimed to detect the inner flaw in concrete structure and iron rods. In addition to the conventional method, we are now developing an innovative inspection system using mobile compact linac driven neutron source to perform neutron backscatter moisture detection method to measure moisture distribution in concrete structure, in order to estimate the corrosion probability distribution of iron rods. Beryllium, having the lowest threshold energy for (gamma, n) reaction, forms the neutron source system combined with our mobile electron linac driven bremsstrahlung X-ray source. The cubic shape beryllium target is surrounded by a boric acid resin layer for neutron ray shield, and a lead layer for gamma/X ray shield. The experiment of moisture detection of concrete structure was conducted using the newly developed mobile linac driven neutron source. 50 g of water under an asphalt sample taken from a real deteriorated bridge of thickness of 7 cm was detected with 1 sigma of confidence level, and the significance level increased to 3 sigma by reducing the background noise.