A Submillimeter Spatial Resolution Scintillation Detector For Time-Of-Flight Neutron Diffraction Imaging

A two-dimensional scintillation neutron detector with a submillimeter spatial resolution was developed for time-of-flight neutron diffraction imaging in the J-PARC MLF. The detector comprised the thin, single ZnS/(LiF)-Li-6 scintillator screen coupled with the crossed wavelength -shifting fiber array for light collection. For a high spatial resolution, the wavelength-shifting fibers with a diameter of 0.1 mm were used for assembling the light collection head. The prototype detector that has a neutron-sensitive area of 24 x 24 mm(2) exhibited a spatial resolution of 0.20 +/- 0.06 mm and 0.16 +/- 0.06 mm for x and y directions, respectively. The detector had a detection efficiency of 7% for thermal neutron with a Co-60 gamma-ray sensitivity in the order of 10(-6). In this paper detector design and specifications are described together with experimental results using the pulsed neutron beam.