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In this paper, the time effect of hydrothermal synthesis on YF3 morphology particles is considered. The work was carried out on X-ray-excited YF3:Ce3+ phosphors. The synthesis was carried out by the hydrothermal method, since it avoids high temperatures leading to particle agglomeration. The first stage of research consisted in identifying the most favorable medium for obtaining the required phase and size - water or organic matter (ethylene glycol and ethanol). Research has shown that ethylene glycol has all the advantages: it prevents agglomeration, allows us to get the required phase. Hydrothermal synthesis of YF3 samples to determine the optimal synthesis time was carried out according to the same scheme - in an organic medium of ethylene glycol without using stabilizers for 4, 8, 12, 16, 20 hours. Our study showed that it is possible to obtain a YF3 sample that meets the necessary requirements (including nanoscale) within 16 hours, moreover, without the use of stabilizers. In parallel with the study of the synthesis duration, an experiment was carried out on the effect of various stabilizers on the properties of the YF3:Ce3+ phosphors (5%). The synthesized nanophosphors possessed effective X-ray luminescence with a maximum in the region of 300 nm, which makes it possible to use them in the composition of preparations for PDT.

We have studied luminescent properties of a ZnO whisker array, a promising crystalline material for scintillation detectors, capable of ensuring a fast and strong response and a short afterglow time. Measurements have been performed under X-ray and UV optical excitation. We present a comparative analysis of spectral features of the near-band-edge emission of the whisker array at low (∼80 K) and room temperatures in relation to the excitation method.

We investigated the morphology and luminescent properties of ZnO tetrapod powders with copper and gold admixtures, obtained by carbothermal pyrolysis. A broad band in the region of 450–650 nm dominates in the X-ray luminescence spectrum of the samples. There is also a weak edge luminescence band with a maximum at 391 nm. Kinetic measurements showed the presence of both fast (~1 ns) and slow (~850 ns) luminescence components, and the fast component, as a rule, did not exceed 1% of the integrated intensity. The used doping method does not result in the incorporation of copper and gold admixtures into the ZnO lattice. The presence of copper at a concentration of up to 9% does not affect the morphology or luminescence properties of ZnO tetrapods, while gold has such an effect even at a concentration close to 1%.

Gd2O2S:Tb phosphors with different terbium content are prepared in a reducing atmosphere at various synthesis conditions. The effect of an activator and Na4P2O7 flux concentrations upon photo-and X-ray induced luminescence of the synthesized samples as well as on their acid-base properties and morphology is studied. The addition of Na4P2O7 flux into the charge mixture leads to a significant increase of the phosphor particle size. A positive correlation is found between the particle size and pH value of the phosphor aqueous slurry. The photoluminescence intensity is found to mostly depend on the activator concentration, while X-ray luminescence intensity primarily depends on the particle size and crystal structure perfectness of the phosphor matrix. Charge mixture compositions and synthesis conditions providing Gd2O2S:Tb phosphors with the highest photo-and X-ray luminescence intensity are determined. A Gd2O2S:Tb phosphor with X-ray luminescence intensity exceeding the values for the commercial phosphor KEP-45 of a similar composition is developed. The obtained phosphors can be used for the manufacture of intensifying screens applied in industrial X-ray flaw detection.

X-ray luminescence spectra of β-Ga2O3 thin films obtained by radio-frequency (RF) ion-plasma sputtering were studied at 80–300 K. The measured spectra were simulated in the framework of the linear electron–phonon coupling model. Luminescence centers with emission maxima at 2.95 and 3.14 eV tended to associate based on the temperature dependence of the selected luminescence bands. The results were analyzed.

CdSe0.02S0.98 quantum dots (QDs), LaF3:Ce3+/CdSe0.02S0.98 nanocomposites (NCs), and CsPbI3 QDs were prepared to compare the properties of photoluminescence (PL) and X-ray excited luminescence (XEL) in these materials. CdSe0.02S0.98 QDs have an intense PL peak but negligible XEL. The LaF3:Ce3+/CdSe0.02S0.98 NCs have a single XEL peak and a corresponding PL peak. The XEL peak in LaF3:Ce3+/CdSe0.02S0.98 NCs originates from a resonance energy transition from LaF3:Ce3+ nanocrystals to CdSe0.02S0.98 QDs. The CsPbI3 QDs, which contain the heavy element Pb (atomic number Z = 82), exhibited a higher XEL than the CdSe0.02S0.98 QDs and the LaF3:Ce3+/CdSe0.02S0.98 NCs.

The Diamond-NaGdF 4 : Eu and Diamond-YAG: Ce film composites were produced by chemical vapor deposition to be used as a source of intensive photo- and X-ray luminescence for radiation monitoring screens.

Cone-beam X-ray luminescence computed tomography (CB-XLCT) is an attractive hybrid imaging modality, and it has the potential of monitoring the metabolic processes of nanophosphors-based dr...

Organic and inorganic luminophores of similar luminescence parameters as diamonds are selected. Indicators, based on the selected luminophores, are synthesized. Spectral and kinetic characteristics of luminophores are experimentally determined for making a decision on optimal compositions to ensure maximum extraction of diamonds in X-ray luminescence separation owing to extra recovery of non-luminescent diamond crystals. As the components of luminophore-bearing indicators, anthracene and K-35 luminophores are selected as their parameters conform luminescence parameters of diamonds detected using X-ray luminescence separator with standard settings.

Two samplings of 65 diamond crystals divided by the intensity of a slow X-ray luminescence component are studied from the Arkhangel’skaya and Karpinskogo-1 pipes. IR and EPR spectroscopies revealed a relationship between the nitrogen A and P2 centers of the diamonds and the presence of a slow X-ray luminescence component. Its absence in most diamonds with high content of P1 (C) centers is explained by the low number of A and P2 centers.

65 diamond crystals from pipes «Arkhangelskaya» and «Karpinskogo-1» was divided into two parts by the intensity of the slow component of x-ray luminescence, and investigated by methods of IR spectroscopy and ESR. The relationship between the content of nitrogen in the diamond centers A and P2 and the presence of the slow component of x-ray luminescence have been found. The absence of this component of greater part of the crystals with a high content centers P1 (C) explained by a small number of centres A and P2

The current work reported an inorganic salt based aggregation-induced emission system which can be excited by X-ray. The underlying mechanism has been systematically studied.

X-ray luminescence computed tomography (XLCT) is an emerging hybrid imaging modality. It has been recently reported that materials such as water, tissue, or even air can generate optical photons upon x-ray irradiation, which can increase the noises in measurements of XLCT. In this study, we have investigated the x-ray luminescence from water, air, as well as tissue mimicking phantoms, including one embedded with a 0.01mg/mL GOS:Eu3+ microphosphor target. We have measured the optical emission spectrum from each sample, including samples of meat and fat, using a spectrograph. Our results indicate that there are plenty of optical photons emitted by x-ray irradiation, and a small nanophosphor concentration, as low as 5.28μM in a deep background, can provide enough contrast for XLCT imaging.

X-ray fluorescence (XF) and X-ray luminescence (XL) are X-ray stimulated processes which can be exploited for medical imaging. In recent years, the computed tomography (XFCT and XLCT) imaging of these processes has attracted much attention especially in the field of radiation therapy. These imaging modalities have potentials to offer additional functional information from the patient during exposure to X-rays for position alignment before the radiation treatment. More recently, these new techniques have been further studied in Monte Carlo simulations and benchtop experiments to characterize and optimize different imaging configurations. This chapter summarizes recent instrumentational developments in X-ray excited imaging; discusses their attributes, advantages, and drawbacks; and describes specifications and applications of various contrast agents for XF- and XLCT. The feasibility of the modalities for future clinical applications will be also highlighted.

Analytical techniques based on luminescence properties of materials have proved to be useful in the study of artistic and archaeological materials. For example, iono-luminescence (IL), in conjunction with ion beam analysis (IBA) techniques, and cathodoluminescence (CL), coupled with optical microscopy or scanning electron microscopy (SEM), are important for identifying mineral phases and provenance studies. X-ray luminescence (XRL) has been used on Cultural Heritage less than other luminescence techniques; we therefore investigated its potential in this field. The first developed setup, necessarily to be used in the laboratory, was tested on a provenance study of the lapis lazuli “Savoy Collection”, kept by the Regional Museum of Natural Sciences in Turin. Very interesting results were obtained: while some samples were labelled as Chilean origin (or simply no attribution), XRL spectra clearly excluded that particular provenance for any specimen of the collection. Although this approach has given valuable information, the potentiality of the technique has not yet been fully exploited due to lack of portability, a great limitation for characterising ancient artefacts. We therefore upgraded the sensitivity of our detection setup, in order to respond also to lower signal levels obtainable with portable X-ray sources. The first results are encouraging and comparable with those obtained with non-portable setups.

X-ray luminescence spectra of Li2B4O7:Er glasses have been investigated in the range of 200–800 nm. It is shown that all identified peaks in the dependence IXRL = f(λ) are due to parity-forbidden intra-configuration radiative transitions within the 4f configuration of Er3+ ion from excited fine-structure levels of higher lying multiplets to the ground-term level 4I15/2.

We report on the study of low-temperature spectra (80–130 K) of X-ray luminescence of Tl 4 CdI 6 crystals. Temperature behavior of the studied X-ray luminescence spectra and identification of their maxima are presented. The recombination mechanisms associated with natural anisotropy of the compounds under study are discussed and the possibility of their practical application is analysed.

Hafnium(IV) was introduced into zeolite Y by allowing anhydrous Cs,Na–Y (|Cs43Na28|[Si121Al71O384]-FAU) to react with HfCl4 (g, 3.2 × 103 Pa) at 503 K for 48 h. The crystal structures of Cs,Na–Y and of the product, Hf,Cl,Cs,Na–Y (|(HfCl)1.5(NaCl)4.5Cs43Na23.5|[Si121Al71O384]-FAU), were determined by single-crystal crystallography at 293 K using synchrotron X-radiation. They were refined in the space group Fd 3 ‾ m (a = 24.808(1) A and 24.735(1) A) with all unique data to the final error indices R1 = 0.062 and 0.067 for the 1572 and 1413 reflections for which Fo > 4σ(Fo), respectively. Their compositions were confirmed by energy-dispersive X-ray analyses. The Hf4+ ions occupy 6-rings in the supercages; each is tetrahedral with three bonds to 6-ring oxygen atoms and one to a Cl− ion. Per unit cell, 4.5 Na+ ions do that also. The remaining Na+ and Cs+ ions occupy well established cation positions near 6- and 12-rings. The sky-blue X-ray induced luminescence spectrum of Hf,Cl,Cs,Na–Y is a broad band from 300 to 650 nm with peaks at 380 nm and 490 nm. This luminescence is blue-shifted compared to that of zeolite Hf,Cl,Cs,Na-A.

A technology, that allows production effective x-ray luminescent phosphors Zn3(PO4)2:Mn2+ with nanosized particles from the water solution by sol-gel method, and directional regulated their luminescence color from green to red was developed. X-ray intensity and spectra, phase structure, and surface properties of synthesized samples depending on the synthesis conditions was studied. The conditions of synthesis which allow to obtain the samples according to the demands for the luminophores of medical assignment were determined.

Ce3+-doped borate crystal fibers of Li6Gd(BO 3)3 (LGBO) and Li6Y(BO3)3 (LYBO) compositions are grown by the micro-pulling down (μ-PD) method for potential application in developing new neutron detectors. The ternary equilibrium diagram of Li2O-Gd2O3-B 2O3 is drawn and the preparations of homogeneous mixed LGBO and LYBO powders and growth conditions for single crystal fibers are discussed. Absorption, excitation and X-ray luminescence spectra are investigated. Absolute light yield derived from energy spectra and kinetic decay curves measured under α- and γ-scintillations of Ce 3+-doped LGBO and LYBO single crystal fibers is provided. © 2012 Elsevier B.V. All rights reserved.

Cone beam X-ray luminescence tomography can realize fast X-ray luminescence tomography imaging with relatively low scanning time compared with narrow beam X-ray luminescence tomography. However, cone beam X-ray luminescence tomography suffers from an ill-posed reconstruction problem. First, the feasibility of experiments with different penetration and multispectra in small animal has been tested using nanophosphor material. Then, the hybrid reconstruction algorithm with KA-FEM method has been applied in cone beam X-ray luminescence tomography for small animals to overcome the ill-posed reconstruction problem, whose advantage and property have been demonstrated in fluorescence tomography imaging. The in vivo mouse experiment proved the feasibility of the proposed method.

The review considers studies of Russian scientists in the recent 20 years devoted to the development of luminescence analysis based on the registration of photoluminescence, chemiluminescence, electroluminescence, and X-ray luminescence.

CaZnGe 2 O 6 :Tb 3+ afterglow phosphors were prepared by solid state reaction using organic coated ZnO nanopowders and their photoluminescence, X-ray luminescence and afterglow properties were investigated. The CaZnGe 2 O 6 :Tb 3+ samples emit a green luminescence at 548 nm attributed to the 5 D 4 – 7 F 5 transition of Tb 3+ . It was observed that the replacement of bulk ZnO by ZnO nanopowder in the sample synthesis increases the luminescence intensity. By adjusting the mass ratio of bulk ZnO to nanopowder ZnO, the photoluminescence intensity, X-ray luminescence intensity, and afterglow efficiency are improved. The optimized sample made with a 0.71 ratio of nano ZnO to bulk ZnO has a factor of four enhancement in X-ray luminescence, photoluminescence and afterglow intensities in comparison with the sample made with 100% bulk ZnO.

Optical molecular imaging is important for biomedical research as it allows non-invasive and quantitative imaging of physiological and pathological processes at the cellular and molecular levels in vivo. Recently, X-ray luminescence computed tomography (XLCT) has been proposed as a promising molecular imaging technique due to its excellent performance. Compared with conventional optical imaging modalities, XLCT has the ability to eliminate autofluorescence. In addition, XLCT can provide increased penetration depth in biological tissues. Furthermore, combined with the advances in nanobiomaterials (nanophosphors), more applications are expected in fundamental researches, especially in clinical practice. In this chapter, we will briefly introduce the XLCT imaging system, computational method, and future directions. An overview of the advantages and challenges of the XLCT technique is first described compared with other molecular imaging techniques. Then, the diverse XLCT imaging systems are classified and summarized. Subsequently, the corresponding reconstruction methods are detailed. Finally, we predict an attractive prospect for XLCT and draw conclusions.

A brief description is presented for a new digital-analog unit designed for recording and processing of signals from photodetectors of an X-ray luminescent separating machine, with a software-supported choice of the diamond detection methods taking into account kinetics of luminescence. Variants of processing the luminescence signals from minerals are considered for a wide range of the luminescence intensity values. The practical results of selecting the optimal diamond detection method are analyzed.

Twenty-five zirconium (hafnium) fluoride compounds have been synthesized at room temperature in the systems MO2-H2SO4-M′nA(HF)-H2O (M = Zr (Hf); M′ = Na, K, Rb, Cs, NH4; A = F, SO4) and their X-ray luminescence spectra (luminescence wavelengths and relative intensities) have been measured. The X-ray luminescence of the compounds has been considered as a function of the composition (cations, anions, water content) and different structural factors (CNs, polyhedra, H-bonds). Ammonium compounds do not luminesce, and sodium fluorozirconates and heptafluorozirconates are weakly luminescing. Hexafluorozirconates M2Zr(Hf)F6 (M= K, Rb, Cs) and M5Zr4F21 · 3H2O (M = Rb, Cs), as well as oxofluorozirconate Rb2Zr3OF12, are strongly luminescing compounds.

物質によっては，X線を照射すると紫外•可視域のX線ルミネセンス光が生じる．本研究では，ZnOエピタキシャル薄膜（ZnO/MgO/Al2O3）を試料に用い，X線ルミネセンス強度の角度依存性の測定を行った．同時にZn Kα線測定による蛍光X線強度（蛍光X線ホログラム）の測定も行い，それとの比較を行った．X線ルミネセンス測定においては，Znの蛍光X線ホログラムと異なり，サファイア基板の構造を反映したホログラムパターンが得られた．この結果より，X線ルミネセンスを用いれば，従来困難であった軽元素の原子分解能ホログラムを測定できる可能性が示された．

A small-scale X-ray-luminescent diamond separator with the digital signal processing designed for retreatment of diamond-bearing concentrates −5 + 2 mm in size is considered. Algorithms of operation, test results, and specifications of the separator are given.

International audience; X-ray luminescence properties of LiLa1−xNdxP4O12 nanocrystals were investigated for the first time. The influence of the Nd3+ concentration on the integral emission intensities in visible and near infrared emission region were investigated. It was found that emission from 2F(2)5/2 is strongly affected by cross-relaxation process and its intensity decreases exponentially with Nd3+ amount, while emission from 4F7/2 + 4S3/2, 4F5/2 + 2H11/2, and 4F3/2 states rises up sublinearly with Nd3+ concentration. The size effect on emission spectra under X-ray excitation was presented.

Dependences accumulation of charge carriers on traps are obtained for kinetic theory of X-ray luminescence and conductivity. Integral characteristics: depending on the luminescent intensity of the excitation intensity, lux-ampere and current-voltage dependence should be linear with X-ray excitation.

Comparative analysis of the experimental results of X-ray luminescence, phosphorescence and thermally-stimulated luminescence intensities for different emission bands in ZnSe revealed that for 630 nm luminescence centers there are two recombination mechanisms existing - electron and hole.

An X-ray imaging detector based on the graded-gap Al x Ga 1− x As structures with the CCD camera as an image read-out tool is investigated. High X-ray – light conversion efficiency and X-ray image spatial resolution better than 20 line/mm are obtained.

This essay outlines the significant work of one group at the Naval Research Laboratory (NRL) during 50 years of leadership in X-ray Fluorescence Analysis (XRF). NRL has produced many of the developments that make XRF analysis the quantitative method that it is today, including the first XRF spectrometer with electronic detection, multichannel analysis of energy dispersive XRF detectors, and public domain software for quantitative analysis. The NRLXRF computer program incorporated fundamental parameters as well as the empirical coefficient methods and treatment of particle size effects into one cohesive and flexible package. The fruits of this research, including the NRLXRF computer code, were actively transferred to industry where they ripened into products which became important in mining, manufacturing, and metals recycling. This legacy continues with the development of technologies for environmental cleanup and for wear monitoring of high value machinery.

TheX-rayluminescencespectraofdopedlithiumtetraboratehavebeenanalyzedonthebasisofaccountingthe set of spectral transitions for different atomic charge states. It has been shown that the X-ray luminescencepeculiarities are to a great extent due to the transitions between the energy levels of dopant atoms and ions, aswellastothelevels,whichformthelithiumtetraboratematrix.PACSnumbers:78.55.Qr,71.55.Ak

This paper reports the X-ray luminescence emission spectra of YTaO4 and GdTaO4 activated by rare-earth ions. The luminescence efficiency of M′-type YTaO4 activated by rare-earth ions was calculated. An assumption model was used to explain the luminescent properties under X-ray excitation. The model assumes that the TaO43− group absorbs all the excitation energy, then transfers part of the energy to rare-earth ions, followed by emission of rare-earth ions. The calculation results agree with experimental results for M′-type YTaO4 activated by Sm3+, Tb3+, and Dy3+. M′-type YTaO4:Eu3+ is an exception because Eu3+ may be involved in the process of energy absorption.

The process of complexing in CsCl crystals in activating them with lead haloids PbX2 (X=Cl, Br, I) (CPbX 2=1 mole %) is investigated. The formation of CsPbCl3 and Cs4PbCl6 microcrystals that are dispersed in the CsCl matrix is recorded. The luminescence-kinetic characteristics of the indicated microcrystals and single Pb2+v c − centers are investigated. It is noted that the formation of the CsPbCl3 and Cs4PbCl6 microcrystals is hindered as the radius of the anion of the lead haloid PbX2 (X=Cl, Br, I) increases.

The CsPbX3 (X=Cl, Br) microcrystals are obtained in a PbX2 (X=Cl, Br) matrix doped with Cs ions (CCs=0.1–1 mol %). Spectral and kinetic parameters of the intrinsic luminescence of the CsPbX3 single crystals are presented. For the CsPbCl3 microcrystals, a quantum-confinement effect is detected, which reveals itself as a decrease in the lifetime of the free exciton luminescence. A mechanism of formation of a CsPbX3 microcrystal in a PbX2 matrix is proposed.