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Preparation and scintillation properties of Eu2+:CaF2 scintillation ceramics
摘要： Different concentration of Eu2+ -doped CaF2 ceramics, designed to the low (0.01 at% and 0.04 at%) and the high (0.2 at% and 0.5 at%), have been prepared by hot-press sintering method. Under 355 nm laser excitation, all the ceramics showed emission bands at 425 nm due to 5d-4f transitions of Eu2+ ions and weak emission peaks at 574, 617 and 630 nm due to the 4-4f transitions of Eu3+ ions. Under X-rays irradiation, the emission bands at 315 nm and 422 nm, ascribed STE and 5d-4f transitions of Eu2+ ions, were observed and the weak emission peaks, ascribed 4f‐4f transitions of Eu3+ ions, were also observed in all the samples. Furthermore, the scintillation decay lifetime and pulse height spectra of the samples were investigated.
关键词： Photoluminescence,Eu2+:CaF2 ceramics,Radioluminescence,Scintillation
更新于2025-09-23 15:22:29
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Dynamic Emission Tuning of X-ray Radioluminescent Crystalline Colloidal Arrays: Coupling the Optical Stop Band with Sequential F?rster Resonance Energy Transfers
摘要： X-ray radiation exhibits diminished scattering and a greater penetration depth in tissue relative to the visible spectrum and has spawned new medical imaging techniques that exploit X-ray luminescence of nanoparticles. The majority of the nanoparticles finding applications in this field incorporate metals with high atomic numbers and pose potential toxicity effects. Here, a general strategy for the preparation of a fully organic X-ray radioluminescent colloidal platform that can be tailored to emit anywhere in the visible spectrum through a judicious choice in donor/acceptor pairing and multiple sequential F?rster resonance energy transfers (FRETs) is presented. This is demonstrated with three different types of ≈100 nm particles that are doped with anthracene as the scintillating molecule to “pump” subsequent FRET dye pairs that result in emissions from ≈400 nm out past 700 nm. The particles can be self-assembled in crystalline colloidal arrays, and the radioluminescence of the particles can be dynamically tuned by coupling the observed rejection wavelength with the dyes’ emission.
关键词： anthracene,F?rster resonance energy transfer,photonic crystals,X-ray radioluminescence,colloidal crystals
更新于2025-09-23 15:21:21
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Remote Measurements of X-rays Dose Rate using a Cerium-doped Air-clad Optical Fiber
摘要： Cerium doped silica glasses are attractive materials for radiation dosimetry. In this work, Ce-doped air-clad optical fiber has been fabricated for real-time X-ray dose rate measurements through the radioluminescence (RL) signal. The structural properties of the obtained material were studied using Raman spectroscopy. The presence of Ce3+ ions inside the sol-gel-derived silica core was confirmed using photoluminescence (PL) measurements. This optical fiber, with a high numerical aperture, was tested as active and guiding material in an all-fibered remote X-ray dosimeter configuration. We demonstrated that the response dependence of RL versus dose rate is linear from 52 mGy(SiO2)/s up to at least 1.5 Gy(SiO2)/s, allowing to monitor the dose rate evolution during an irradiation run. The presented results confirm the potentialities of this microstructured optical fiber to monitor ionizing radiations in harsh environments. They also pave the way towards an alternative to the widely used approach that uses a scintillator material at the end of a transport optical fiber.
关键词： radioluminescence,cerium,Dosimetry,X-ray radiation,optical fiber
更新于2025-09-23 15:19:57
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Recent Advances in Silica Glass Optical Fiber for Dosimetry Applications
摘要： In this paper, we review the highly promising silica glass, fabricated as doped and undoped optical fiber for intended use in radiation dosimetry. The dosimetry techniques reviewed here, underpinned by intrinsic and extrinsic defects in silica glass, focus on Thermoluminescence (TL), Optically Stimulated Luminescence (OSL) and Radioluminescence (RL), with occasional references to the much more established Radiation Induced Attenuation (RIA). The other focus in this review is on the various materials that have been reported earlier as dopants and modifiers used in silica glass optical fiber radiation dosimeters. This article also elaborates on recently reported optical fiber structures, namely, cylindrical fibers, photonic crystal fibers and flat fibers, as well as dimensions and shapes used for optimization of dosimeter performance. The various types of optical fiber radiation dosimeters are subsequently reviewed for various applications ranging from medical dosimetry such as in external beam radiotherapy, brachytherapy and diagnostic imaging, as well as in industrial processing and space dosimetry covering a dynamic dose range from μGy to kGy. Investigated dosimetric characteristics include reproducibility, fading, dose response, reciprocity between luminescence yield to dose-rate and energy dependence. The review is completed by a brief discussion on limitations and future developments in optical fiber radiation dosimetry.
关键词： radioluminescence,thermoluminescence,Silica optical fiber,review,dosimetry
更新于2025-09-23 15:19:57
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Radioluminescence in biomedicine: physics, applications, and models
摘要： The electromagnetic spectrum contains different frequency bands useful for medical imaging and therapy. Short wavelengths (ionizing radiation) are commonly used for radiological and radionuclide imaging and for cancer radiation therapy. Intermediate wavelengths (optical radiation) are useful for more localized imaging and for photodynamic therapy. Finally, longer wavelengths are the basis for magnetic resonance imaging and for hyperthermia treatments. Recently, there has been a surge of interest for new biomedical methods that synergize optical and ionizing radiation by exploiting the ability of ionizing radiation to stimulate optical emissions. These physical phenomena, together known as radioluminescence, are being used for applications as diverse as radionuclide imaging, radiation therapy monitoring, phototherapy, and nanoparticle- based molecular imaging. This review provides a comprehensive treatment of the physics of radioluminescence and includes simple analytical models to estimate the luminescence yield of scintillators and nanoscintillators, Cherenkov radiation, air fluorescence, and biologically endogenous radioluminescence. Examples of methods that use radioluminescence for diagnostic or therapeutic applications are reviewed and analyzed in light of these quantitative physical models of radioluminescence.
关键词： Cherenkov luminescence,nanotechnology,Radioluminescence,biomedical imaging,scintillators,radiation therapy
更新于2025-09-11 14:15:04
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Tunable luminescent properties of BaGd <sub/>2</sub> O <sub/>4</sub> :Eu <sup>3+</sup> scintillating phosphors by Pr <sup>3+</sup> -codoping
摘要： BaGd2O4:Eu3+ scintillating phosphors by Pr3+‐codoping were synthesized at 1300°C in air using a solid‐state reaction method. The as‐synthesized phosphors were characterized by X‐ray diffraction (XRD), photoluminescence (PL) including excitation radioluminescence (RL) spectra excited by X‐ray and and emission spectra, thermoluminescence (TL) spectra. Both the PL and RL spectra are composed of the featured trivalent europium (Eu3+) without any praseodymium (Pr3+) ions, and the PL and RL intensities as well as the lifetimes of BaGd2O4:Eu3+ scintillating phosphors decrease dramatically with an increasing concentration of Pr3+ ions. Finally, the TL spectra reveal the trap concentration of the existing defects decrease with an increasing concentration of Pr3+ ions, while the relative TL intensity ratio of the high temperature band to the low temperature one increases with an increasing concentration of Pr3+ ions, which results in the afterglow suppression of BaGd2O4: Eu3+ scintillating phosphors.
关键词： radioluminescence,photoluminescence,BaGd2O4:Eu3+ scintillating phosphors by Pr3+‐codoping,thermoluminescence
更新于2025-09-09 09:28:46
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β-Ga2O3:Ce as a fast scintillator: An unclear role of cerium
摘要： β-Ga2O3 and β-Ga2O3:Ce crystals have been grown by the Czochralski method and their scintillation properties have been studied by means of pulse height, radioluminescence and scintillation time profile measurements. It is shown that although the scintillation of β-Ga2O3:Ce is related to intrinsic excitonic emission, the doping with Ce improves some characteristics of the material. The prominent samples of β-Ga2O3:Ce display fast 6 ns (40%) scintillation, with total light yields of about 5000 ph/MeV.
关键词： scintillation,scintillation decay,β-Ga2O3 crystal,Ce-doped β-Ga2O3 crystal,radioluminescence
更新于2025-09-04 15:30:14