HIGH RESOLUTION RADIATION IMAGER

摘要

A radiation imager includes a photosensor array that is coupled to a scintillator so as to detect optical photons generated when incident radiation is absorbed in the scintillator. The imager includes an optical crosstalk attenuator that is optically coupled to a first surface of the scintillator (that is, the surface opposite the photosensor). The optical crosstalk attenuator includes an optical absorption material that is disposed so as to inhibit reflection of optical photons incident on the scintillator first surface back into the scintillator along selected crosstalk reflection paths. The crosstalk reflection paths are those paths oriented such that optical photons passing along such paths would be incident upon photosensor array pixels that are outside of a selected focal area corresponding to the absorption point in the scintillator. The imager further may include an optical screen layer that is optically coupled to the scintillator second surface so as to be disposed between the scintillator and the photosensor array. The optical screen layer is made of a substantially transparent material selected to have a critical index of refraction so as to cause preferential reflection of optical photons that are incident on the screen layer to reduce optical crosstalk.