Subsurface Engraved Scintillation Crystals for Radiation Detectors

Principal Investigator: Robert Miyaoka

The detection of ionizing radiation is an important part of PET tomography, a means to detect radiation from an ingested or injected tracer to visualize metabolic processes. Radioisotopes from the tracer emit positrons that travel short distances and encounter electrons, an interaction which produces a pair of gamma photons. Scintillation detectors absorb these high-energy photons and emit a corresponding wavelength of light. This visible light is then detected by photomultiplier tubes, resulting in an image. The spatial resolution of the image is largely determined by the size and distribution of individual crystals within the detector, and a current need exists to make these scintillator detectors both more sensitive and cost-effective.

UW investigators propose a novel method for creating scintillation crystals using subsurface laser engraving, a process which is used to generate point-like defects in the crystal to alter the path of scintillation photons. By arranging these defects in a variety of boundaries, depths, and shapes, the inventors can influence the properties of the detector.

• The patterning of these defects can serve as an optical boundary or element in a variety of crystals, lenses, or light guides. 

• The density or distribution of these defects influences the deflection of light in the crystal. 

• The orientation of the defects can limit the lateral spread of photons.

For more info, contact: Lisa Norton