A time-of-flight neutron imaging detector using ZnS/6LiF scintillator and wavelength shifting fibers with high spatial resolution and with low gamma-ray sensitivity

The ZnS scintillator-based two-dimensional detector was developed for time-of-flight neutron imaging with a high spatial resolution and with a low gamma-ray sensitivity. The developed detector based on neutron counting method exhibited a high spatial resolution of less than 100 μm in full width at half maximum with a moderate count rate capability of several tens kcps. Its low gamma-ray sensitivity of less than 10-7 is also of particular interest. The detector is comprised of a thin ZnS/6LiF scintillator screen with crossed wavelength-shifting fiber (WLS fiber) arrays equipped with the fiber optic taper (FOT). Neutron imaging capabilities of the detector have been demonstrated by using a high-intensity pulsed neutron beam at the Materials and Life Science Experimental Facility in the Japan Proton Accelerator Complex (J-PARC).