A scintillator-based detector with sub-100-μm spatial resolution comprising a fibre-optic taper with wavelength-shifting fibre readout for time-of-flight neutron imaging

摘要

A scintillator-based neutron-counting imaging detector with a sub-100-μm spatial resolution was developed for energy-selective neutron imaging. The detector head of the detector comprised a thin ZnS/~6LiF scintillator screen, a fibre-optic taper and crossed wavelength-shifting (WIS) fibre arrays. A high spatial resolution was achieved by constructing the scintillator with a thickness of 100 μm and placing it in contact with the fibre-optic taper at a magnification ratio of 3.1:1. WLS fibres with a diameter of 100 ± 5 μm (mean ± SD) were specially made, and their dye content was optimized for use in crossed WLS-fibre arrays. The developed detector had a pixel size of 34 μm × 34 μm, and exhibited spatial FWHM resolutions of 80 ± 7 μm and 61 ± 6 μm in the × and y directions, respectively. A small prototype detector demonstrated the capability of neutron imaging using Bragg edges of a Cu/Fe sample when using the pulsed-neutron source in the Materials and Life Science Experimental Facility at the Japan Proton Accelerator Research Complex.