High-resolution X-ray imaging with samarium-doped fluoroaluminate and fluorophosphate glass

Edgar, A.; Varoy, Chris; Koughia, Cyril; Okada, Go; Belev, George; Kasap, S. O.

doi:10.1016/j.jnoncrysol.2012.12.022

Cited by 23 publications

(8 citation statements)

References 16 publications

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“…Sm doped glasses were synthesized using a melt quenching technique previously described in detail elsewhere [27][28][29][30][31][32][33][34][35]. Starting materials were mixed in a glove box in a dry nitrogen atmosphere and loaded in a carbon crucible where the mixture was then melted in an RF furnace at 1000 °C for 120 min.…”

Section: Sm 3+ -Doped Fluoroaluminate and Fluorophosphate Glass Platesmentioning

confidence: 99%

“…Response values for samples irradiated were measured using a custom confocal fluorescence microscopy readout system, which has been described in some detail previously [27][28][29][30][31][32][33]. Figure 1 shows a schematic of the confocal microscopy apparatus.…”

Section: Optical Measurement Technique: Modified Fluorescence Confoca...mentioning

confidence: 99%

“…The change of valence from Sm 3+ to Sm 2+ upon x-ray irradiation can be used as a measure of the x-ray dose delivered. Previous work with Sm-doped FA and FP glasses examined the conversion of Sm 3+ to Sm 2+ over a wide range of doses and demonstrated the reusability of bulk doped samples by reversing the valence change from Sm 2+ to Sm 3+ after extended UV exposure or annealing above the glass transition temperature [27][28][29][30][31][32][33][34][35]. The glass transition temperatures for FA and FP glasses were measured to be approximately 440 °C and 462 °C, respectively.…”

Section: X-ray Response Calibration Curves and Equationsmentioning

confidence: 99%

“…These PL signals are then measured using a modified fluorescence confocal microscopy detection system that is tuned to the emission wavelengths of these ions. Using this method it has been shown that resolution on the order of microns can be achieved [27][28][29][30][31][32][33][34][35].This works investigates one of the most important issues in the calibration of any detector for accurate dose measurement: the dependence of the response of the detector to the incident x-ray energy and the incident dose rate. We have examined the conversion of Sm 3+ to Sm 2+ of Sm-doped FA and FP glasses over a wide range of dose rates (four orders of magnitude) and energy values (35-130 keV) and how these Sm-doped plates can be calibrated so that they measure the correct incident dose.…”

Section: Introductionmentioning

confidence: 99%

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Instrumentation for high-dose, high-resolution dosimetry for microbeam radiation therapy using samarium-doped fluoroaluminate and fluorophosphate glass plates

Chicilo

Okada

Belev

et al. 2019

Meas. Sci. Technol.

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We show that 1% Sm-doped fluoroaluminate (FA) glass plate and a suitably modified fluorescence confocal microscope provide an excellent radiation detection platform for high-dose measurements at high resolution down to the micron scale. We have used a custom-modified fluoroscopic confocal microscope apparatus to scan, separate, detect, and digitize the photoluminescence signals from Sm 3+ and Sm 2+ ions in both FA and fluorophosphates (FP) glasses within a selected focal depth of the microscope below the sample surface. The response (R) of Smdoped FA and FP glass plates to incident x-ray radiation was studied in detail in which R was defined as the difference in the ratio of photoluminescence (PL) signals from Sm 2+ and Sm 3+ before and after irradiation. We report on a number of important issues related to the use of these Smdoped FA and FP glass plates in microbeam radiation therapy (MRT) dosimetry: The dependence of the Sm 3+ to Sm 2+ conversion, and hence R on the dose rate over some four orders of magnitude; the energy dependence of R at a given dose rate for both FA and FP samples with various concentrations of Sm 3+ doping; R vs dose behavior at different energies up to 2000 Gyair and the derivation of the detector calibration curves; the stability of the Sm-doped plates after they have been exposed; the instrumental limits of the present measurement technique.

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Section: Sm 3+ -Doped Fluoroaluminate and Fluorophosphate Glass Platesmentioning

confidence: 99%

Section: Optical Measurement Technique: Modified Fluorescence Confoca...mentioning

confidence: 99%

Section: X-ray Response Calibration Curves and Equationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Instrumentation for high-dose, high-resolution dosimetry for microbeam radiation therapy using samarium-doped fluoroaluminate and fluorophosphate glass plates

Chicilo

Okada

Belev

et al. 2019

Meas. Sci. Technol.

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“…The aim of this work was the synthesis, characterization, and dosimetric testing of an oxyfluoride glass‐ceramic containing CaF 2 :Sm 3+ nanocrystals as a new potential dosimeter material to be used for MRT applications. It should be emphasized that Sm‐doped glasses and glass‐ceramics in this work are not necessarily limited to applications in MRT, inasmuch as Sm‐doped materials have, in recent years, been widely studied for a variety of optoelectronic applications such as X‐ray imaging phosphors, optical waveguides, three‐dimensional optical memories, pressure sensors, white LEDs, and solar cells …”

Section: Introductionmentioning

confidence: 99%

Samarium‐Doped Oxyfluoride Glass‐Ceramic as a New Fast Erasable Dosimetric Detector Material for Microbeam Radiation Cancer Therapy Applications at the Canadian Synchrotron

et al. 2014

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There is a special need to develop a dosimetry technique with a large-dynamic range and high-spatial resolution to characterize the microstructured X-ray beams used in microbeam radiation therapy (MRT) for cancer. We report the synthesis and characterization of oxyfluoride glass-ceramic (SiO 2 -Al 2 O 3 -CaF 2 -CaO-SmF 3 ) plates, which contain trivalent-samarium-doped calcium fluoride (CaF 2 :Sm 3+ ) nanocrystals, for use as a dosimetric detector material, particularly for MRT applications. Our approach utilizes the extent of Sm 3+ ?Sm 2+ valence reduction caused by X-ray irradiation as a probe of the X-ray dose delivered; and confocal fluorescent microscopy is used to read out the distribution of valence reduction through the photoluminescence (PL) signal. Our study showed that the Sm 3+ ?Sm 2+ valence reduction takes place in CaF 2 nanocrystals, but not in the glass matrix. The Sm 2+ shows PL emission predominantly due to the fast 4f 5 5d 1 ? 7 F 0 transition, which allows us to read out the detector plate at a high scanning speed. Further, our experiments showed that the detection dose range reaches several thousands of grays, and X-ray dose distribution is detected at a micrometer scale. In addition, the Sm 2+ signal can be erased either by heating the irradiated sample at a suitable high temperature or by exposing it to UV light; and the erased glass-ceramic plate is reusable. The new Sm-doped oxyfluoride glass-ceramic with CaF 2 nanocrystals reported in this work shows potential for practical use in highdose and high-resolution dosimetry for MRT. J. McKittrick-contributing editorManuscript No. 34020.

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Luminescent Materials

Edgar

2017

Springer Handbook of Electronic and Photonic Materials

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This chapter surveys the field of solid-state luminescent materials, beginning with a discussion of the different ways in which luminescence can be excited. The internal energy-level structures of luminescent ions and centres, particularly rareearth ions, are then discussed before the effects of the vibrating host lattice are included. Having set the theoretical framework in place, the chapter then proceeds to discuss the specific excitation process for photo-stimulated luminescence and thermally stimulated luminescence before concluding by surveying current applications, including phosphors for compact fluorescent and LED lighting, long-term persistent phosphors, x-ray storage phosphors, and scintillators. Luminescent materials are substances which convert an incident energy input into the emission of electromagnetic waves in the ultraviolet (UV), visible or infrared regions of the spectrum, over and above that due to black-body emission. A wide range of energy sources can stimulate luminescence, and their diversity provides a convenient classification scheme for luminescence phenomena, which is summarised in Table 38.1. Photoluminescence, where the luminescence is stimulated by UV or visible light, is a widely used materials science technique for characterising dopants and impurities, and finds applications in lighting technologies such as fluorescent and solid state lamps. Radioluminescence involves excitation by ionising radiation, and is used in scintillators for nuclear particle detection; the special case of stimulation by energetic electrons is called cathodoluminescence, the name arising from early atomic physics experiments involving gas discharges. Electroluminescence involves collisional excitation by internal electrons accelerated by an applied electric field, and with a much lower energy than in the case of cathodoluminescence. Electroluminescence finds applications in panel lighting used in some liquid-crystal display (LCD) back-planes, in inorganic light-emitting diodes (LEDs) and organic light-emitting diodes (OLEDs).There are other forms of luminescence which we mention for completeness but will not discuss further: bioluminescence and chemiluminescence where the energy input is from chemical or biochemical reactions, sonoluminescence (sound wave excitation), and triboluminescence (strain or fracture excitation). Both organic and inorganic systems can display luminescence, but here we focus primarily on inorganic systems.There are several books which describe the luminescence and spectroscopy of inorganic materials [38.1-4] and applications to phosphors and scintillators [38.5, 6] in more depth than is possible in a short article.The terms phosphorescence and fluorescence are often used in connection with luminescent materials. This classification is based on the time-domain response of the luminescent system. Figure 38.1 shows a generic

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High-resolution X-ray imaging with samarium-doped fluoroaluminate and fluorophosphate glass

Cited by 23 publications

References 16 publications

Instrumentation for high-dose, high-resolution dosimetry for microbeam radiation therapy using samarium-doped fluoroaluminate and fluorophosphate glass plates

Instrumentation for high-dose, high-resolution dosimetry for microbeam radiation therapy using samarium-doped fluoroaluminate and fluorophosphate glass plates

Samarium‐Doped Oxyfluoride Glass‐Ceramic as a New Fast Erasable Dosimetric Detector Material for Microbeam Radiation Cancer Therapy Applications at the Canadian Synchrotron

Luminescent Materials

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