Sub-surface Laser Engraving in Thick Hexagonal Scintillation Crystals

Positron Emission Tomography detectors are commonly dense pixelated inorganic scintillators. These are embedded in a reflector whose thickness hinders the sensitivity. Pixel arrays manufacturing is laborious and expensive. The extensively known laser processing can be employed as an alternative. A g...

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Bibliographic Details
Published in2021 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC) pp. 1 - 4
Main Authors Perez-Benito, D., Chil, R., Hidalgo-Torres, L. A., Vaquero, J. J.
Format Conference Proceeding
LanguageEnglish
Published IEEE 16.10.2021
Subjects
Crystals
Energy resolution
Image resolution
Lasers
Optical imaging
Scintillators
Sensitivity
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Summary:Positron Emission Tomography detectors are commonly dense pixelated inorganic scintillators. These are embedded in a reflector whose thickness hinders the sensitivity. Pixel arrays manufacturing is laborious and expensive. The extensively known laser processing can be employed as an alternative. A grid of laser induced microcracks at the focal spot creates a semitransparent optical barrier to guide scintillation light towards the photosensor. In this work, a cost-effective nanosecond laser has been used to validate this approach. Its design flexibility has been exploited to develop hexagonal patterns of 1.25 mm of edge to serve a hexagonal photodetector, building block of an innovative quasi-spherical scanner. Field flood images of individual readout in LYSO blocks of 5 mm, 7 mm and 10 mm of thickness are presented alongside the pixel resolvability. Depth of interaction has been developed with two shifted layers of 5 mm in a 10 mm crystal. The crystal resolvability and energy resolution confirm the validity of the engraving solution in a complete system.
ISSN:2577-0829
DOI:10.1109/NSS/MIC44867.2021.9875879