Optical-interface patterning for radiation detector crystals

Abstract

A radiation detector is disclosed that includes a scintillation crystal and a plurality of photodetectors positioned to detect low-energy scintillation photons generated within the scintillation crystal. The scintillation crystals are processed using subsurface laser engraving to generate point-like defects within the crystal to alter the path of the scintillation photons. In one embodiment, the defects define a plurality of boundaries within a monolithic crystal to delineate individual detector elements. In another embodiment, the defects define a depth-of-interaction boundary that varies longitudinally to vary the amount of light shared by neighboring portions of the crystal. In another embodiment the defects are evenly distributed to reduce the lateral spread of light from a scintillation event. Two or more of these different aspects may be combined in a single scintillation crystal. Additionally, or alternatively, similar SSLE defects may be produced in other light-guiding elements of the radiation detector.

Description

[0001] Cross Reference Related Applications [0002] This application claims the benefit of US Provisional Application No. 61 / 255,047, filed October 27, 2009, which is incorporated herein by reference in its entirety. [0003] Statement of Government Franchise Rights [0004] This invention was made with government support under EB002117 awarded by National Institutes of Health, National Institutes of Biomedical Imaging and Bioengineering. The government has certain rights in this invention. Background technique [0005] Scintillation crystal radiation detection systems rely on the interaction of high-energy photons, such as gamma rays, with scintillation materials in Compton scattering or photoelectric interactions. Scintillation events generate a large number of low energy photons that are more easily detected with photodetectors, such as photomultiplier tubes, silicon photomultipliers, and the like. [0006] Exemplary scintillation crystals include NaI(TI) (thallium-dope...

AI Technical Summary

Problems solved by technology

However, given the small crystal cross-sections required to achieve very high resolution, discrete crystal designs are generally expensive, have low packing fraction, reduced light collection, and are labor intensive to construct of

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