A Combined method of small-angle neutron scattering and neutron radiography to visualize water in an operating fuel cell over a wide length scale from nano to millimeter

Iwase, Hiroki; Koizumi, Satoshi; Iikura, Hiroshi  ; Matsubayashi, Masahito  ; Yamaguchi, Daisuke; Maekawa, Yasunari; Hashimoto, Takeji

We constructed an in-situ and simultaneous observation method as a result of combination between ultra-small-angle neutron scattering and neutron imaging (radiography). With this novel technique, we are able to visualize water distribution or transportation, occurring from micro to macro length scales in a polymer electrolyte fuel cell (PEFC). At a sample position of SANS-J-II at JRR-3, we installed a neutron imaging camera in order to construct an in-situ and simultaneous observation method by USANS and neutron imaging with monochromatized cold neutrons. In addition, in order to selectively observe MEA in a running PEFC by using the in-situ and simultaneous observation method, we need to replace carbon separators which cause strong small-angle scattering as a noise. To reduce this strong background, we replaced the carbon separators with the aluminium ones. As a result, the background scattering was minimized (1/10) as compared to before.