Development of multi pinhole aperture for improving spatial resolution with wide imaging area

Hayashida, Hirotoshi; Segawa, Mariko   ; Yasuda, Ryo; Iikura, Hiroshi  ; Sakai, Takuro; Matsubayashi, Masahito  

Improvement of spatial resolution is common needs of users of in neutron radiography (NR) in various research fields such as materials, fuel cell, architecture, and so on. High collimator ratio (L/D) is one of the most significant factors for high spatial resolution imaging, because size of the geometric unsharpness formed on an image is inversely proportional to L/D. Small aperture collimator system is effective for increasing L/D of neutron radiography system. In case of using a small aperture system on thermal neutron radiography facility (TNRF) in JRR-3, the imaging area is 20 mm by 20 mm, being not enough area to view large size samples. We are developing multi pinhole collimator in order to spread imaging area with high L/D.