A 6Li doped glass scintillator sheet with grooves cut at given spacings
in horizontal and vertical directions. Bundles of wavelength shifting fibers placed
in the vertical grooves and fluorescence reflector buried in the horizontal grooves
make a group of detection pixels. Neutron detecting media are provided on the top
surface and bundles of wavelength shifting fibers are arranged horizontally on
the bottom surface of the scintillator. Fluorescence generated by stimulation with
the neutrons entering the detection pixels and with the neutrons incident on the
neutron detecting media are detected by the wavelength shifting fibers. The detected
fluorescence is converted to electric signals with a multi-channel photomultiplier
tube, with pulse signals for simultaneous counting generated from a retriggerable,
constant time-duration pulse generator and recorded as time-series data by parallel
interfaces. The recorded data are analyzed by the simultaneous counting method
to produce a two-dimensional neutron image.
