Patent ID: 7214943

Claim:
A two-dimensional radiation or neutron image detector which detects radiation or neutron using a scintillator or phosphor as a detection medium and a wavelength shifting optical fiber as a constituent material, wherein the scintillator or phosphor as the detection medium is underlaid with a parallel array of wavelength shifting fibers having sensitivity to the fluorescence emitted from either detection medium and which can absorb the fluorescence with an efficiency of no more than 50%, said first array of wavelength shifting fibers being backed with another parallel array of wavelength shifting fibers having the same characteristics as above such that the two arrays of wavelength shifting fibers are crossed at right angles, the two perpendicular arrays being backed with a scintillator or phosphor as the detection medium, and wherein the position pulse signals for the horizontal and vertical axes as obtained from the two arrays of wavelength shifting fibers are subjected to coincidence counting to determine the two-dimensional incident position of radiation or neutron.