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Dense and transparent ceramic samples of a (Gd,Y)3Al2Ga3O12:Ce scintillator were obtained by using stereolithography-based Digital Light Processing (DLP) 3D printing for compacting, subsequent burnout, and pressureless sintering. The effects of stoichiometric deviations and green body compaction methods (uniaxial pressing versus DLP 3D printing) on the optical, luminescent, and scintillation properties of ceramics were analyzed. An excess of Y and Gd in the composition led to an increase in transmittance and to the acceleration of the scintillation kinetics. Moreover, transparent ceramics made of 3D-printed green bodies were found to be superior in light yield to the samples, which were prepared from the same powders and densified by uniaxial pressing. [ABSTRACT FROM AUTHOR]

The large size (4 cm × 4 cm × 1 cm) Ce3+-doped high gadolinium oxyfluoride glass with density of 5.83 g/cm³ was prepared by the melt quench method at 1220 °C. The glass is colorless and transparent over the visible range. The prolonged decay time under 275 nm UV light demonstrates the energy transfer from Gd3+ ions to Ce3+ ions. The X-ray excited luminescence spectra (XEL) show the emission peak corresponds to the 5d→4f transitions of Ce3+ ion. The integral emission intensity of glass was compared with that of bismuth germanate oxide (BGO) crystals. The scintillation property of glass was studied under the γ -ray from 137Cs source and a clear energy peak was observed with light yield (LY) over 1100 ph/MeV. The scintillation decay time comprises fast and slow components. All results presented in this work indicate the appropriate potential to be high-energy rays detecting material for CEPC. [ABSTRACT FROM AUTHOR]

Inorganic scintillation crystals have been widely used in applications of high-energy physics, nuclear medical imaging, industrial nondestructive inspection, etc. In this work, a single crystal Ba3Y(PO4)3 (BYP) with 1.0 at% Ce3+-doping concentration was first grown by the Czochralski method, and the electronic structure was calculated using first principles based on density functional theory. In addition, a series of Ce3+-doped BYP phosphors were synthesized, and the fluorescence emission under UV excitation was measured through low-temperature spectroscopy, containing double-peaked emission from 5d–4f transition and self-trapped exciton recombination. A comparison of the UV and X-ray-excited fluorescence spectra reveals the existence of oxygen vacancies as well as F+ centers in the crystal. The air annealing of the crystal effectively reduces the thermoluminescence defects but reduces the emission intensity under UV or X-ray excitation. The BYP:Ce crystal shows a fast decay lifetime of 15.5 ns, and the fast component is as short as 8 ns. The results show that the Ce3+-doped BYP crystal has potential as a kind of scintillator with fast decay properties. [ABSTRACT FROM AUTHOR]

LuBO3 crystallizes in the calcite type (CaCO3) structure and is a widely applied inorganic host for luminescent materials and scintillators. Even though many scientific works have been published concerning the optical properties of rare-earth-doped LuBO3, so far, no study of the emission spectra as function of the excitation energy of such orthoborates has been conducted. Therefore, this work elaborates on the photoluminescence of RE-doped LuBO3 with RE = Ce3+, Eu3+, Gd3+, or Tb3+, while an emphasize is laid on the energy dependence of these four luminescent compounds. The reflection, emission, and excitation spectra were additionally recorded, and the particle size distribution was determined. Calcite type LuBO3 was successfully obtained, and the characteristic RE luminescence was observed. Furthermore, the Gd3+-doped sample showed no scintillation due to its monovalence and a sensitizer is required to transfer the respective energy to the Gd3+-activator. [ABSTRACT FROM AUTHOR]

Ce-doped gadolinium gallium aluminum oxide (Ce: GGAG) precursors were first prepared by the microwave-assisted homogeneous precipitation method (MAHP). Thermal gravity-differential thermal analysis (TG-DTA), X-ray diffraction (XRD), specific surface area analysis (BET) and field emission scanning electron microscopy (FE-SEM) were employed to investigate the crystal structure, phase evolution and morphologies of the Ce: GGAG precursors and powders. The influence of Ga ion concentration in the salt solution on the properties of Ce: GGAG powders was investigated. All the precursors were transformed into single-phase GGAG after being calcined at 950 °C in a furnace for 3 h. Monodispersed Ce: GGAG powders were obtained as the Ga ion concentration was lower than 0.06 mol/L. Single-phase and dense Ce: GGAG ceramics were obtained after sintering at 1600 °C in a flowing oxygen atmosphere for 10 h. Specifically, the Ce: GGAG ceramic reached its maximum density of ~6.68 g/cm3, which was close to its theoretical density of 6.70 g/cm3, and exhibited the highest optical transmittance of 65.2% at 800 nm after hot isostatic pressing sintering (HIP) as the Ga ion concentration was 0.02 mol/L. The decay time and light yield of the GGAG ceramic were 35 ns and 35,000 ± 1250 ph/MeV, respectively, suggesting that Ce: GGAG ceramics prepared using MAHP-synthesized nanopowders are promising for scintillation applications. [ABSTRACT FROM AUTHOR]

The photoluminescence (PL) and scintillation properties of Ce-doped BaHfO3 crystals were investigated. The Ce-doped BaHfO3 crystal is transparent and colorless after annealing treatment under a reduction condition. The broad luminescence band at ~370 nm was observed under ~280 nm excitation with the decay time of ~17 ns. The X-ray-induced scintillation spectra also showed the broad luminescence band at ~380 nm with a fast decay. The origin of the broad luminescence band at ~380 nm is attributed to the 5d-4f transition of Ce3+. The pulse height distribution under 137Cs gamma ray irradiation using Ce-doped BaHfO3 exhibited a distinguishable photoabsorption peak. The light yield of Ce-doped BaHfO3 is ~1600 photons/MeV. [ABSTRACT FROM AUTHOR]

The photoluminescence (PL), scintillation, and thermally stimulated luminescence (TSL) properties of Eu-doped (0.01, 0.1, and 1%) Al2O3 single crystals grown by the floating zone method were investigated systematically. The PL of the samples showed several sharp emission peaks across 550-750 nm originating from the 4f-4f transitions of Eu3+ and the 3d-3d transitions of Cr3+ impurity ions. The scintillation spectrum of the samples showed a broad emission peak at 320 nm due to the F+ center and an emission peak at 700 nm due to the 3d-3d transitions of Cr3+ impurity ions. All the samples showed TSL glow peaks at around 200, 320, and 375 °C. The TSL intensity of the 1% Eu-doped sample was the highest among the present three samples, and the TSL response was proportional to the irradiated X-ray dose in the range from 10 to 1000 mGy. The Eu-doped Al2O3 single crystal could be a novel candidate for personal dose monitoring applications. [ABSTRACT FROM AUTHOR]

The relationship between the lifetimes and emission wavelengths of scintillation and photoluminescence, when the initial excited state was the same, was studied. When the rate equation is dominant, lifetime should be the same at different emission wavelengths. However, we have observed the dependence of lifetime on emission wavelength in common scintillators. [ABSTRACT FROM AUTHOR]

In this paper, we report the first Bi4Ge3O12-based thin-layer alpha radiation detector. The scintillator was immobilized on a fused silica substrate via pulsed laser irradiation of BGO powder consisting of submicron particles. Laser treatment conditions were shown to influence the morphology and kinetic characteristics of the scintillator. The material we prepared ensures a higher stability of detectors to moisture and air in comparison with its commercially available analogs, while offering a comparable or even higher detection efficiency, and can be used in environmental monitoring, including volumetric alpha activity measurements. [ABSTRACT FROM AUTHOR]

Plasma irregularity in the equatorial and low-latitude ionosphere, which leads to ionospheric scintillation, can threaten the operation of radio-based communication and navigation systems. A method for forecasting scintillation activity is still pending. In this study, we examined the performance of ionospheric parameters, including the critical frequency (foF2), peak height of the F2-layer (hmF2), scale height (Hm) and virtual height (h'F), around local sunset from ground-based ionosonde observations, and also the characteristics of Equatorial Ionization Anomaly (EIA) derived from Gravity Recovery and Climate Experiment (GRACE) observations in equinoctial months (March–April and September–October) during high solar activities (2012–2013) at a low-latitude station at Sanya (18.3° N, 109.6° E; dip lat.: 12.8° N), China. Furthermore, the simplified linear growth rate of Rayleigh–Taylor (R–T) instability inferred from ionosonde measurements and EIA strength derived from GRACE observations were used to estimate the day-to-day occurrence of post-sunset scintillation. The results indicate that it is not adequate to determine whether scintillation in a low-latitude region would occur or not based on one ionospheric parameter around sunset. The simplified growth rate of R–T instability can be a good indicator for the day-to-day occurrence of scintillation, especially in combination with variations in EIA strength. An index including the growth rate and EIA variations for the prediction of the post-sunset occurrence of irregularity and scintillation is proposed; the overall prediction accuracy could be about 90%. Our results may provide useful information for the development of a forecasting model of the day-to-day variability of irregularities and scintillation in equatorial and low-latitude regions. [ABSTRACT FROM AUTHOR]

Thin luminescent films of the organometallic complex of lithium 8-hydroxyquinolate Liq on glass substrates were fabricated by capillary deposition and lithography. The spectral-luminescent properties of the obtained film structures were investigated. The film surface was analyzed. The light yield and the kinetics of scintillation emission of the obtained film structures are estimated. [ABSTRACT FROM AUTHOR]

GYAGG:Tb (Ce) scintillators have been confirmed to be promising sources of light emission when excited by an intense 150 keV electron beam. The saturation of the scintillation yield under such excitation conditions has been studied. To explain the results obtained, a model that considers the Auger quenching mechanism was used. The Ce-doped material did not show saturation, whereas a moderate 30% drop of the yield was measured in the Tb-doped sample at the highest excitation beam intensity ~1 A/cm2. This put forward a way to exploit the Tb-doped scintillator for indirect β-voltaic batteries. [ABSTRACT FROM AUTHOR]

Ce-doped 20CsBr-20BaBr2-60ZnBr2 glasses were synthesized by the conventional melt quenching method, and their photoluminescence (PL) and scintillation properties were investigated. In the PL and scintillation spectra, all the Ce-doped glasses showed broad emissions due to the 5d-4f transitions of Ce3+ ions. Under 241Am α-rays, the light yield of 0.05% Ce-doped glass was 40 photons/5.5 MeV-α. [ABSTRACT FROM AUTHOR]

Ce:(MgxCa1-x)HfO3 (x = 0.5, 2.5, 5, and 10%) single crystals were successfully grown by the floating zone method, and their photoluminescence (PL) and scintillation properties were investigated. A broad luminescence band with a maximum at 430 nm was observed in both the PL and scintillation spectra. The PL quantum yield (QY) improved with the substitution of Mg, and the PL QY of Ce:(MgxCa1-x)HfO3 reached 50%. Fast decay due to the 5d-4f transition of Ce3+ was observed for both the PL and scintillation. Ce:(MgxCa1-x)HfO3 (x = 5%) showed the highest light yield of ~9500 photons/MeV among the synthesized samples, and this value is higher than that of common X- and gamma-ray detection scintillators such as Bi4Ge3O12 and Ce:Gd2SiO5 single crystals. [ABSTRACT FROM AUTHOR]

This research revealed the response of Ga and Al sublattices to the incorporation of mismatching substituents in Gd3Al2Ga3O12:Ce single crystals. Incompatible in size and charge, Li+ and Mg2+ substituents violated configurational entropy. This led to lattice distortion and triggered structural rearrangements. The radial fluctuation of the Ga and Al elements was proven by multi-elemental energy-dispersive X-ray spectroscopy mapping and elemental composition analysis. Further evidence was observed by the shift of the exciton creation energy toward higher energy in the vacuum ultraviolet excitation spectra recorded with synchrotron radiation. In the Li+ and Mg2+ co-doped samples, the crystal core was depleted with Ga atoms and enriched with Al elements. The crystal rim showed the opposite behavior. The change in thermoluminescence peak positions revealed a different mechanism for the formation of localized traps. As a result, Li+ co-doping slightly improved the light yield value, but at the same time decelerated the scintillation decay time. On the contrary, Mg2+ co-doping markedly diminished scintillation parameters. [ABSTRACT FROM AUTHOR]

We have devoted efforts to the development and performance evaluation of new low-cost ionospheric instruments for studies that require distributed observations and for educational and citizen science initiatives. Here, we report results of some of these efforts. More specifically, we describe the design of new ionospheric sensors based on Global Navigation Satellite System (GNSS) receivers and single-board computers. The first sensor (ScintPi 2.0) is a multi-constellation, single-frequency ionospheric scintillation monitor. The second sensor (ScintPi 3.0) is a multi-constellation, dual-frequency ionospheric scintillation and total electron content (TEC) monitor. Both sensors were created using Raspberry Pi computers and off-the-shelf GNSS receivers. While they are not intended to fully replace commercial ionospheric monitors, they cost a fraction of their price and can be used in various scientific applications. In addition to describing these new sensors, we present examples of observations made by ScintPi 3.0 deployed in Presidente Prudente, Brazil (22.12 S, 51.41 W, − 17.67° dip latitude). These examples show the ability of our system to detect scintillation events and TEC depletions such as those associated with equatorial plasma bubbles. Additionally, our observations were made in parallel with a commercial receiver (Septentrio PolaRx5S), which allowed an evaluation of the scintillation and TEC measurements provided by our system. The comparison shows that ScintPi 3.0 can provide estimates of the amplitude scintillation index (S4) and TEC that are in excellent agreement with those provided by PolaRx5S. We also show an example of the application of ScintPi 3.0 in distributed observations of ionospheric irregularities and scintillation over South America. [ABSTRACT FROM AUTHOR]

Calorimetric space experiments were employed for the direct measurements of cosmic-ray spectra above the TeV region. According to several theoretical models and recent measurements, relevant features in both electron and nucleus fluxes are expected. Unfortunately, sizable disagreements among the current results of different space calorimeters exist. In order to improve the accuracy of future experiments, it is fundamental to understand the reasons of these discrepancies, especially since they are not compatible with the quoted experimental errors. A few articles of different collaborations suggest that a systematic error of a few percentage points related to the energy-scale calibration could explain these differences. In this work, we analyze the impact of the nonproportionality of the light yield of scintillating crystals on the energy scale of typical calorimeters. Space calorimeters are usually calibrated by employing minimal ionizing particles (MIPs), e.g., nonshowering proton or helium nuclei, which feature different ionization density distributions with respect to particles included in showers. By using the experimental data obtained by the CaloCube collaboration and a minimalist model of the light yield as a function of the ionization density, several scintillating crystals (BGO, CsI(Tl), LYSO, YAP, YAG and BaF2) are characterized. Then, the response of a few crystals is implemented inside the Monte Carlo simulation of a space calorimeter to check the energy deposited by electromagnetic and hadronic showers. The results of this work show that the energy scale obtained by MIP calibration could be affected by sizable systematic errors if the nonproportionality of scintillation light is not properly taken into account. [ABSTRACT FROM AUTHOR]

The crystals of (Lu,Gd)3(Ga,Al)5O12 multicomponent garnets with high density ρ and effective atomic number Zeff are characterized by high scintillation efficiency and a light yield value up to 50,000 ph/MeV. During recent years, single-crystalline films and composite film/crystal scintillators were developed on the basis of these multicomponent garnets. These film/crystal composites are potentially applicable for particle identification by pulse shape discrimination due to the fact that α-particles excite only the film response, γ-radiation excites only the substrate response, and β-particles excite both to some extent. Here, we present new results regarding scintillating properties of selected (Lu,Gd)3(Ga,Al)5O12:Ce single-crystalline films under excitation by alpha and beta particles and gamma ray photons. We conclude that some of studied compositions are indeed suitable for testing in the proposed application, most notably Lu1.5Gd1.5Al3Ga2O12:Ce film on the GAGG:Ce substrate, exhibiting an α-particle-excited light yield of 1790–2720 ph/MeV and significantly different decay curves excited by α- and γ-radiation. [ABSTRACT FROM AUTHOR]

Nd-doped CaWO4 single crystals with dopant concentrations of 0.1, 0.5, and 1% were synthesized by the floating zone method. The transmission, photoluminescence, and scintillation properties were evaluated from ultraviolet to near-infrared (NIR) ranges. An emission peak due to transitions of the host was observed at 400 nm, and several sharp peaks originating from Nd3+ 4f–4f transitions were confirmed at 900, 1060, and 1300 nm. The quantum yields of 0.1, 0.5, and 1% Nd-doped samples were 70.7, 79.5, and 61.2%, respectively, when monitored, and excited wavelengths were 750–1500 nm and 590 nm. Decay times consistent with typical Nd3+ transitions were obtained when NIR ranges were monitored. Additionally, the energy transfer between the host and Nd3+ occurred according to the decay measurement. The relationship between X-ray irradiated dose rate and intensity in the range of NIR was investigated by combining the crystals with an InGaAs-photodiode. The lowest detectable dose rate retaining the linearity of the present crystals was 0.3–0.06 Gy/h. [ABSTRACT FROM AUTHOR]

Sm-doped SrCl2 crystals were prepared, and the scintillation properties such as emission spectra, decay profiles, and pulse height were investigated. Under X-ray irradiation, a broad band can be observed at 680 nm, which indicates that the major origin is due to 5d-4f transitions of Sm2+. The decay curve is approximated by one exponential function with a decay time of 10 μs, and the decay time constant is typical for Sm2+. From the pulse height of 137Cs γ-rays, 0.1% Sm:SrCl2 shows a light yield of 33,000 photons/MeV. [ABSTRACT FROM AUTHOR]

The photoluminescence (PL) and scintillation properties of (C6H5C2H4NH3)2Pb1-xCuxBr4 (x = 0.05, 0.1, 0.25, and 0.5) single crystals prepared by the poor-solvent diffusion method were evaluated. In the PL profiles, free- and bound-exciton luminescence peaks at 410 and 440 nm were observed, respectively. The PL quantum yields (QYs) of the x = 0.05, 0.1, 0.25, and 0.5 samples were 20.0, 19.3, 18.4, and 16.7% with 2% errors, respectively. In the scintillation profiles, a bound-exciton luminescence peak was observed at 440 nm. Under γ-ray exposure with 137Cs, a photoabsorption peak was observed in all the samples, and the scintillation light yields of the x = 0.05, 0.1, 0.25, and 0.5 samples were estimated to be ~12000, ~11000, ~10000, and ~9700 ph/MeV with 10% errors, respectively. [ABSTRACT FROM AUTHOR]

In recent years, several coordination polymers of different dimensions and metal–organic frameworks were tested and expected to be good candidates for closing the gap between organic and plastic scintillators on the one hand side and inorganic scintillators on the other hand side. In the present work, we report the synthesis and characterization of a novel one-dimensional scintillating coordination polymer based on cadmium(II), N,N'-(1,4-phenylenedicarbonyl)di-glycinate, and 2,2'-bipyridine. Crystals could be obtained from water–methanol solutions and the structure was determined by single-crystal diffraction. The coordination polymer exhibits scintillation under X-ray excitation and laser as well as UV-light induced photoluminescence with fast decay times. Photoluminescence and X-ray excited optical luminescence (XEOL) properties and decay times were performed using a two-dimensional photon counting streak camera system with a time resolution up to 20 ps. The non-covalent interactions and supramolecular assemblies as a potential multiplier of the scintillating effect were investigated with the aid of a Hirshfeld surface analysis. The quality and phase purity of the used crystals and pellets was clarified by powder diffraction and Rietveld refinement. [ABSTRACT FROM AUTHOR]

X-ray luminescence and scintillation characteristics of CsPbBr3 crystal from the perovskites family were investigated over the temperature range of 7-200 K. At low temperatures CsPbBr3 was found to be a very bright scintillator with the fast response demonstrating a very short decay time constant 1 ns at 7 K. The light output was measured to be 109 000 ±22 000 ph/MeV at excitation with α-particles of 241Am. The obtained results testify that CsPbBr3 is a very potent scintillation material, which would compete with the commercial analogues in the case of the cryogenic applications. Besides, the study has clarified the origin of the intense slow component observed below 70 K that would be considered an obvious disadvantage for the scintillator applications, since it causes an afterglow. It has been shown that the corresponding radiation is due to the impurities and capture centers. This implies possibility for elimination of the slow component by optimization of the material using an improved growth process. [ABSTRACT FROM AUTHOR]

The main directions in the development of the spectral systems for scintillation atomic emission analysis of powdered geological samples are aimed at increasing the sensitivity, spectral resolution, and speed of the spectrum analysis to reduce the detection limits. The goal of this study is development of high-speed multichannel emission spectrum analyzers with hybrid assemblies of arrays consisting of 14 photodetectors of two types, high-sensitivity BLPP-2000 array and high spatial resolution BLPP-4000 array, and theoretical estimation of the signal-to-noise ratio for scintillation and integral spectra recorded with the aforementioned photodetectors. The design of the high-speed MAES analyzers with BLPP-2000 and BLPP-4000 photodetector arrays provides parallel readout of arrays in hybrid assemblies. The Grand spectrometer equipped with such arrays consisting of 14 BLPP-2000 or BLPP-4000 photodetectors can record spectra in the 190–350 nm wavelength range. The minimum exposure time is 0.9 and 1.7 ms, respectively. It is shown that, when intensities of spectral lines are measured using the BLPP-2000 arrays, the signal-to-noise ratio is 3 times higher in integral analysis and 5 times higher in scintillation analysis as compared to measurements using the BLPP-4000 arrays. [ABSTRACT FROM AUTHOR]

Indirect flat panel detectors (I‐FPDs) enable digital radiography at high X‐ray energies. However, the performance of these devices is limited due to the large number of X rays that pass through them undetected. The authors hypothesize that a glass‐based scintillator may serve as a substrate for the thin film transistors and photodiodes in an I‐FPD, leading to improvements in X‐ray detection for improved performance. The authors synthesized a series of five glass‐ceramic scintillators based on an oxyhalide glass matrix. Each glass ceramic contains barium chloride crystals which serve as scattering centers to prevent "light trapping" in the material; barium chloride is also a well‐known scintillation crystal. Four of the samples contain trivalent terbium, which serves as a second luminescent center. The light output of each sample was compared against a well‐known X‐ray scintillator, gadolinium oxysulfide (GOS) under RQA9 exposure conditions, in the back‐irradiation configuration. The addition of terbium oxide to the glass composition increases the detected light output, which varies by concentration. The thickness of the glass‐ceramic scintillator has a profound effect on performance, with the results influenced by such factors as self‐attenuation of emission in the thicker samples and decreased X‐ray capture in the thinner samples. The brightest sample tested achieved a light output 13% that of the GOS intensifier screen. The results indicate that the use of scintillating glass‐ceramic substrates should lead to increased performance in indirect digital radiography. [ABSTRACT FROM AUTHOR]

Photoluminescence and X-ray-induced scintillation properties of xCe:20BaO-15Gd2O3-65SiO2 (x = 0, 0.01, 0.05, 0.1, 0.5) glasses were investigated. The glass samples emitted light via energy transfer from Gd3+ in the host to Ce3+. The 6P7/2-8S7/2 relaxation of Gd3+ was confirmed notably in the undoped glass sample, but the emission due to Gd3+ disappeared upon the addition of Ce. Furthermore, the decay time constant of Gd3+ decreased with increasing Ce concentration. [ABSTRACT FROM AUTHOR]

We successfully developed Eu-doped SrBr2 transparent ceramics with different Eu concentrations by spark plasma sintering and evaluated their optical and scintillation properties. As optical properties, the diffuse transmittance of the 0.01% Eu-doped sample was ~60% in the visible range. All the samples showed two absorption bands at around 250 and 350 nm, the origin of which was the 4f-5d (eg, t2g) transitions of Eu2+. Regarding scintillation spectra, the spectral shapes of all the Eu-doped SrBr2 transparent ceramics were similar to that of single crystals. In pulse height spectra, the photoabsorption peak of the 0.01 and 0.1% Eu-doped samples was confirmed, and the estimated light yields were 6600 and 13300 photons/MeV, respectively. Regarding afterglow properties, the afterglow levels of the 0.01 and 0.1% Eu-doped samples were comparable to that of a conventional Tl-doped CsI scintillator. [ABSTRACT FROM AUTHOR]

Scintillators emitting near-infrared (NIR) photons have unique characteristics and have been attracting attention recently. For example, scintillators emitting NIR photons are expected to be effective tools for radiation dose monitoring in high-dose environments. In this study, YAlO3 samples doped with various rare-earth ions (Er3+, Ho3+, Pr3+, and Tm3+) were synthesized by the floating zone method and their scintillation properties from the UV to NIR range were evaluated. Regarding their scintillation detection property, the Er3+-doped sample indicated an approximately linear proportional relationship from 1 mGy to 10 Gy. [ABSTRACT FROM AUTHOR]

We synthesized ZrO2 and yittria-stabilized ZrO2 crystals by the floating zone (FZ) method to evaluate their scintillation properties. Under excitation at around 250 nm, the photoluminescence (PL) emission peak appeared at around 450 nm. In the X-ray-induced scintillation spectra, an intense emission peak was also observed at around 450 nm in all the samples. The scintillation decay time profiles were approximated by a sum of two exponential decay functions, and the obtained value varied from 30-90 and 300-2230 ns depending on the composition. [ABSTRACT FROM AUTHOR]

Ce-doped SrHfO3 crystals were synthesized by the floating zone (FZ) method, and their photoluminescence (PL) and scintillation properties were investigated. X-ray diffraction (XRD) measurement indicates that the samples are mainly composed of SrHfO3, but a small peak due to HfO2 is observed. In both PL and scintillation analyses, the Ce-doped samples show the emission peaking around 410 nm, whose decay time is short due to the 5d-4f transitions of Ce3+. In the undoped sample, the emission appears around 480 nm. In the afterglow curves after 2 ms X-ray irradiation, no significant concentration dependence is observed. [ABSTRACT FROM AUTHOR]

CsCl transparent ceramics were prepared by the spark plasma sintering (SPS) method, and their optical, scintillation, and dosimetric properties were investigated. To evaluate the potential of the transparent ceramics, a CsCl single crystal was prepared by the vertical Bridgman-Stockbarger method. Regarding the luminescence properties, the vacuum UV (VUV)-excited photoluminescence (PL) and scintillation spectral features of the transparent ceramics were similar to those of the single crystal. Concerning the thermally stimulated luminescence (TSL) properties, the minimum detection limit of the transparent ceramics was 0.01 mGy. [ABSTRACT FROM AUTHOR]

Ce:CsCl transparent ceramics doped with different concentrations of Ce (0.01, 0.1, and 1 mol.%) were synthesized by spark plasma sintering, and their optical, scintillation and dosimetric properties were investigated. Regarding the scintillation properties, X-ray-induced scintillation spectra of the samples consisted of three emission peaks at around 280, 380, and 400 nm, which were due to the Auger-free luminescence and 5d→4f (²F5/2 and ²F7/2) transitions of Ce3+, respectively. In addition, the samples showed thermally stimulated luminescence (TSL) and optically stimulated luminescence (OSL) with emission peaks centering at around 400 and 480 nm, in which the origins were attributed to the 5d--4f transitions of Ce3+ and the host, respectively. In particular, the TSL was sensitive to X-rays, and the TSL signals as low as 0.1 mGy were measurable, while a linear response was confirmed up to 100 mGy. [ABSTRACT FROM AUTHOR]

The scintillation properties of Pr:CaF2 were studied in comparison with those of Eu:CaF2 under α-ray excitation using a sealed source of 241Am. The relative light yields of the Pr:CaF2 crystals were approximately 0.6-13% of the Eu:CaF2 crystal that is known as a conventional scintillator for charged-particle detection. The scintillation decay times of the Pr:CaF2 crystals were significantly faster than that of the Eu:CaF2 crystal. Therefore, the Pr:CaF2 crystals can be used for charged-particle measurements with high count rates. [ABSTRACT FROM AUTHOR]

(Lu,Y)AlO3 crystals doped with different concentrations of Nd were synthesized by the floating-zone (FZ) method to evaluate their scintillation properties, particularly in the near-infrared (NIR) range. Under X-ray irradiation, scintillation due to the 4F3/2→4 I11/2 transition of Nd3+ was observed at 1064 nm. The scintillation decay time profile was approximated by an exponential decay function, and the obtained value varied from 2-3 to 150 μs depending on the concentration of Nd3+. [ABSTRACT FROM AUTHOR]

Physical structures found in the vicinity of GNSS receivers can introduce multipath interference effects when a signal arrives at the receiver by different routes. Multipath effects are well recognized as one of the most significant sources of error that degrade the accuracy of GNSS signals for navigation and positioning applications. These effects also reduce the quality of GNSS data used for ionospheric studies. The principal cause of multipath effects is proximity of the antenna to reflecting structures and it is more pronounced when the signal comes from a satellite with low elevation. Typically, conservative fixed-elevation thresholds of 20–40° are used to filter out signals from low elevation angles, but this leads to the exclusion of a significant quantity of useable data. In this paper we present a series of azimuth-dependent elevation thresholds that were developed by characterizing the multipath environment of the GPS Ionospheric Scintillation and TEC (Total Electron Content) Monitor (GISTM) receivers installed by SANSA (South African National Space Agency) at Mauritius (20.14°S and 57°E), Marion Island ( 46.87 ° S and 37.86 ° E) and SANAE IV in Antarctica ( 71.73 ° S and 2.2 ° W). The threshold masks were developed from azimuth-elevation maps of the S 4 index, σ ϕ index, the Code-Carrier Divergence Standard Deviation (CC-STDDEV) and the L1 Carrier-to-Noise Density (L1 CNo) from 1-min scintillation data taken over a period of 10–12 months at each location to identify signals that are distorted by multipath effects. Using the azimuth-dependent elevation threshold (ADET) mask typically gives 22–28% more useful data than using a fixed-elevation threshold at the sites studied in this paper. [ABSTRACT FROM AUTHOR]

Transparent and yellowish Ce-doped SrHfO 3 (Ce:SHO) single crystals were grown by the xenon lamp equipped floating zone method. The synthesized crystals were in the single phase of SHO crystal structure, and no impurity phases such as HfO 2 were evident by the X-ray diffraction analysis. The Ce:SHO shows blue luminescence peaking at 410 nm in both the PL and scintillation spectra, and the decay time constant was approximately 14 ns. The PL QY increases with the Ce concentration, which was confirmed up to 5%. The afterglow level is the lowest when the Ce concentration is 3%. The full energy peak can be demonstrated with all the Ce:SHO single crystals prepared in this study under 241Am alpha-ray irradiation, and the estimated light yield is 396 photons/MeV for the 3% Ce:SHO, which is the highest among the samples studied. • Transparent and yellowish Ce-doped SrHfO 3 (Ce:SHO) single crystals were synthesized by the xenon lamp equipped floating zone method. • Ce:SHO showed blue luminescence with the maximum peak at 410 nm in both the photoluminescence and X-ray-induced scintillation spectra. • The full energy peak was observed in all the Ce:SHO single crystals under 241Am alpha-ray irradiation. [ABSTRACT FROM AUTHOR]

A common technique for the determination of the activity of tritiated water (HTO) is liquid scintillation counting (LSC). This implies sample taking, sample preparation and radioactive waste processing afterwards. When handling highly tritiated water special care has to be taken because of possible harmfulness of the sample. Furthermore, LSC devices are mostly large, heavy and expensive. The TRAMPEL experiment aims at measuring the activity of tritiated water in-line without sample taking. The device is intended to be easy to use and operate, quite inexpensive and compact. The measurement principle is based on electrons from β-decay which induce light in commercially available scintillation fibres. The light is detected by a small photomultiplier tube (PMT). A proof-of-principle was set up for static measurements using standard stainless steel parts. The complete device has a volume of less than 0.5 l. [ABSTRACT FROM AUTHOR]

Highlights: [•] Ce3+-doped dense scintillating glasses containing Gd2O3 and Lu2O3 were prepared. [•] Increasing the concentration of Gd2O3 and Lu2O3 can increase the light yields. [•] The highest light emission intensity excited by X-ray is 87% of BGO. [•] The decay time constants are in the range of 30–40ns. [•] The energy transfer from Gd3+ to Ce3+ plays an important role in the glasses. [ABSTRACT FROM AUTHOR]