Passive solid-state detectors based on the optical reading of the visible photoluminescence (PL) emitted by radiation-induced F2 and F+3 colour centres in lithium fluoride (LiF) have been successfully tested for X-ray imaging. They are characterized by high spatial resolution, wide dynamic range, large field of view, non-destructive readout capability, and simplicity of use. Optically-transparent polycrystalline LiF films of increasing thickness (0.5 and 1.1 μm) grown by thermal evaporation on glass and Si(100) substrates were irradiated with monochromatic 7 keV X-rays at several doses from 13 to 1.4 × 103 Gy at the SOLEIL synchrotron facility. For all the LiF films, the spectrally-integrated visible PL signal intensity was found to depend linearly on the irradiation dose, with films grown on Si(100) substrates exhibiting up to a 50% higher response compared to those grown on glass. The minimum dose of 13 Gy was detected, despite the low thickness of the irradiated films. A spatial resolution of (0.54 ± 0.02) μm was obtained in edge-enhancement imaging experiments conducted by placing an Au mesh in front of the LiF film detectors.
Photoluminescent colour centres in lithium fluoride film imaging detectors for monochromatic hard X-rays
Vincenti M. A.;Montereali R. M.;Nichelatti E.;Nigro V.;Piccinini M.;
2024-01-01
Abstract
Passive solid-state detectors based on the optical reading of the visible photoluminescence (PL) emitted by radiation-induced F2 and F+3 colour centres in lithium fluoride (LiF) have been successfully tested for X-ray imaging. They are characterized by high spatial resolution, wide dynamic range, large field of view, non-destructive readout capability, and simplicity of use. Optically-transparent polycrystalline LiF films of increasing thickness (0.5 and 1.1 μm) grown by thermal evaporation on glass and Si(100) substrates were irradiated with monochromatic 7 keV X-rays at several doses from 13 to 1.4 × 103 Gy at the SOLEIL synchrotron facility. For all the LiF films, the spectrally-integrated visible PL signal intensity was found to depend linearly on the irradiation dose, with films grown on Si(100) substrates exhibiting up to a 50% higher response compared to those grown on glass. The minimum dose of 13 Gy was detected, despite the low thickness of the irradiated films. A spatial resolution of (0.54 ± 0.02) μm was obtained in edge-enhancement imaging experiments conducted by placing an Au mesh in front of the LiF film detectors.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
