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The zero-dimensional copper halide perovskite Cs 3 Cu 2 I 5 displays extraordinary luminescence and scintillation characteristics, and high-quality crystals are extremely desirable for exploring the commercial applications. Currently, the most critical issue in the solution growth of Cs 3 Cu 2 I 5 crystals is the easy oxidation of halides, which significantly hinders the optimization of crystal qualities. The hypophosphorous acid (H 3 PO 2) has been applied to inhibit the oxidation, nevertheless, the related mechanism is elusive and has been largely ignored. Herein, Cs 3 Cu 2 I 5 crystals have been grown from N, N-Dimethylformamide (DMF) solvent by the antisolvent vapor-assisted crystallization (AVC) method. It is verified that H 3 PO 2 effectively prevents the oxidation of Cs 3 Cu 2 I 5 by rapidly reducing Cu2+ and I 3 −, maintaining the stability of the precursor solution and continuously suppressing oxidation during the whole growth process. Meanwhile, by increasing the acidity of the solution, H 3 PO 2 dissolve precursor colloids and efficiently enhance the solubility of halides. Thus, the addition of H 3 PO 2 favors the rapid growth of centimeter-sized Cs 3 Cu 2 I 5 crystals with well-defined crystallographic planes within several days. As excellent gamma ray scintillator, the crystal exhibits high light yield of 38000 photons/MeV, with energy resolution of 5.6 % under 662 keV radiation from a 137Cs source. This work deeply elucidates new insight into the critical effect of H 3 PO 2 in the DMF based solution crystal growth, facilitating the preparation of large-size and high-performance copper halide perovskite crystals. [ABSTRACT FROM AUTHOR]

High-performance and low-cost metal halide perovskite scintillator materials have important applications in X-ray detection and imaging. However, large-sized perovskite scintillator panel with high transmittance, low toxicity and long-term stability is still lacking. Herein, Eu2+ doped cesium alkaline earth chloride nanocrystals (Eu2+: CsCaCl 3 , Eu2+: CsSrCl 3 , and Eu2+: Cs 2 BaCl 4 NCs) embedded in glasses through conventional melt-quenching and subsequent heat-treatment were developed. These NCs doped glasses exhibited highly efficient and narrowband photoluminescence in blue region. Benefitting from the large X-ray absorption coefficient and high photoluminescence quantum yied, these Eu2+: CsCaCl 3 NCs doped glass scintillator shows light yield of ∼9300 photons/MeV, detection limit of ∼213.8 μGy/s, and spatial resolution of 30.0 lp/mm. These results demonstrated that glasses containing Eu2+ doped cesium alkaline earth chloride nanocrystals are promising for X-ray detection and imaging. [ABSTRACT FROM AUTHOR]

X-ray excited radioluminescence was demonstrated in Pr-doped lithium niobate polycrystalline samples with varying lithium-to-niobium ratios (R LN). The samples' phase structures, excitation and emission spectra, and radioluminescence were experimentally analyzed to investigate the tuning effects of R LN. Theoretical calculations based on Density Functional Theory (DFT) were conducted to elucidate the underlying mechanisms, and thermoluminescence curves were measured to verify the predictions of the theoretical analysis. We suggest that both photoluminescence and radioluminescence properties can be effectively tailored by adjusting the crystal structure, as well as the depth and density of electron traps within the LiNbO 3 :Pr matrix through R LN modulation. This research contributes to the development and practical implementation of scintillation materials derived from rare-earth-doped lithium niobate. [ABSTRACT FROM AUTHOR]

The study of scintillation-causing ionospheric irregularities is important to mitigate their effects on satellite communications. It is also important due to the spatial and temporal variability of these irregularities, given that their characteristics differ from one region to another. This study investigates the spatial and temporal characteristics of L1 amplitude scintillation-causing ionospheric irregularities over the Eastern Arabian Peninsula during the ascending phase of solar cycle 25 (years 2020–2023). The temporal occurrences of weak and strong scintillation were separated by sunset, with weak scintillation observed predominantly pre-sunset during the winter solstice and strong scintillation observed mainly post-sunset during the autumnal equinox. Strong scintillation was much more pronounced in 2023 compared to the other three years, indicating a strong influence of solar activity. Spatially, weak-scintillation-causing irregularities exhibited a wide distribution in azimuth and elevation, while strong-scintillation-causing irregularities were concentrated southwards. The combined analysis of S4 and rate of total electron content index (ROTI) suggested that small-scale ionospheric irregularities were present in both pre- and post-sunset periods, while large-scale irregularities were only seen during the post-sunset period. Furthermore, the presence of southward traveling ionospheric disturbances (TIDs) during the 2023 autumnal equinox was confirmed with the total electron content anomaly (Δ TEC), while the Ionospheric Bubble Index (IBI) provided by the Swarm mission was unable to confirm the presence of equatorial plasma bubbles during the same period. Observations from the FORMOSAT-7/COSMIC-2 mission indicated that strong-scintillation-causing irregularities were more prevalent under the F2-layer peak, while the weak-scintillation-causing irregularities were mostly observed at the E-layer, F2-layer, and above the F2-layer. This study aims to contribute insights into the behavior of scintillation-causing ionospheric irregularities in the region, with implications for future research during the peak of the 25th solar cycle. [ABSTRACT FROM AUTHOR]

Due to the rapid advancements in medical radiography, nondestructive inspection, and radiation detection, there is an increasing demand for scintillators that offer both cost-effectiveness and high-resolution X-ray imaging. In this study, we have successfully synthesized transparent glass-ceramic scintillator by embedding Tb3+-doped NaLu 2 F 7 nanocrystals in a glass matrix. This scintillator demonstrates excellent spatial resolution of 20 lp/mm in X-ray imaging due to its high transmittance (over 90% at 550 nm) and intense luminescent intensity when excited by X-ray (151% higher than that of the Bi 4 Ge 3 O 12 scintillator). More significantly, the as-synthesized scintillator exhibits exceptional stabilities at high temperature, moisture levels, and moderate radiation exposure. Notably, any decline in performance caused by long-term exposure to high-dose X-ray can be fully recovered through heat treatment at 350 °C for 30 min. These findings highlight the great potential of NaLu 2 F 7 :Tb3+ glass ceramics as suitable options for high-resolution and retrievable X-ray imaging. [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]

Upconversion nanoparticles (UCNPs), particularly those that are highly doped, possess outstanding properties and have demonstrated tremendous application potential. However, novel fine-tuning strategies are urgently required to enhance the upconversion luminescence (UCL) performance of UCNPs. In this study, a series of core–multishell UCNPs highly doped with Ho3+ and Yb3+ ions were synthesized via the oleate route. The X-ray diffraction (XRD), transmission electron microscopy (TEM), and UCL spectra and decay times, and pump power dependency of the synthesized UCNPs were used to examine their morphology, size, and the UCL properties. Ce3+ ions were introduced to enhance Ho3+-based red UCL, and their doping strategy was also optimized based on summarized UCL trends and detailed UCL mechanism analysis. NaHoF 4 :Gd3+@NaGdF 4 :Yb3+,Ce3+@NaGdF 4 :Yb3+ UCNPs that had 10 mol% Ce3+ dopants in their middle shells exhibited better UCL properties than the larger traditional NaGdF 4 :Yb3+,Ce3+,Ho3+ UCNPs, probably because of the combined influence of the energy interactions between the Ce3+ ions and surface groups, sensitizing energy enhancement by active shells, and the positive cooperation between the Ce3+ ions and highly-doped core–shell structures. In this study, the phenomenon of UCL decrease resulting from Ce3+ ion doping was explored. Using unique core–multishell structures with highly-doped activators and sensitizers placed within and outside the structures, respectively, the UCL decrease due to Ce3+ ion doping was attributed to a competition for photons. Doping the UCNPs with Ce3+ ions near the UCNP surfaces favors Ho3+-based red UCL. Our study findings can deepen the understanding of the Ho3+-based UCL mechanisms and increase the potential uses of NaHoF 4 materials in photo-induced therapy. When Ce3+ ions are doped near the nanoparticle surface, they might have energy interactions with surface groups to relieve phonon energy shortage and thus enhance the efficiency of cross-relaxation between Ho3+ and Ce3+ ions. [Display omitted] [ABSTRACT FROM AUTHOR]

The phosphor-converted white light-emitting diodes (pc- w LEDs) are current research hotspot. To meet simultaneously the requirements of high chemical/thermal stability and color-rendering index (CRI), low correlated color temperature (CCT) for actual application is still not be perfectly achieved. Herein, we studied for the first time the incorporation of Ce3+ (blue-emitting) and Mn2+ (orange/red emission) into the dibarium magnesium phosphate ceramic (Ba 2 Mg(PO 4) 2 , BMP) for packaging of pc- w LEDs via remote 'capping' approach, which exhibits highly efficient color-tunable photoluminescence (PL) with splendid chemical/thermal stability, single-phase/full-color-PL, efficient energy transfer (ET). To reduce the impact of heterovalent substitution (Ba2+ ← Ce3+), the monovalent (Li+, Na+, K+) ion, respectively tridoped in BMP: Ce/Mn and played both roles as flux and charge compensator, were also studied/compared on the basis of PL efficiency, where Na+ is the most effective because of the lowest electronegativity mismatch between the Ba2+ and Na+. An alkaline-earth-metal-ion blending strategy via partial replacement of Ba2+ with Sr2+ was implemented to further regulate PL and obtain better parameters of CCT/CRI due to the variations of crystal field splitting. The site occupations of Ce/Na/Sr in Ba sites (CN = 8 and 7) and Mn in Mg site (CN = 6) were based on the comparisons of ion radius and confirmed by XRD/Rietveld analyses, where Ce/Na/Sr ions gave priority to occupy the Ba site with CN = 8 due to their much closer ion radius. Altogether, the stably composition-optimized BMP: Ce/Mn/Na/Sr has great potential application as a single-component color-tunable phosphor in n -UV pumped pc- w LEDs. The pc- w LED fabricated via remote 'capping' approach by combination of a n -UV chip with BMP: Ce/Mn/Na/Sr phosphor through Ce to Mn ET with the help of charge compensator of Na and the alkaline-earth-metal-ions blending by Ba/Sr replacement. [Display omitted] • Ce/Sr/Na occupied at Ba sites while Mn sited in Mg sites. • ET occurs efficiently from Ce to Mn. • Na + acts as charge balancer to improve PL efficiency. • Replacing partial Ba by Sr could regulate PL and improve ET efficiency. • pc- w LED via ' n -UV LED + white-emitting BMP: Ce/Mn/Na/Sr' is achieved. [ABSTRACT FROM AUTHOR]

• CeBr 3 and NaI (Tl) scintillators characterized with array of Silicon Photomultipliers. • Energy resolution improves with lower shaping time and higher SiPM over-voltage. • Temperature dependency of gain of SiPM array: ∼−0.81 %/°C for overvoltage of 2.5 Volts. • Temperature dependency of light yield for CeBr 3 : ∼−0.27 %/°C for −31 °C to +26 °C. • Temperature dependency of light yield for NaI (Tl): ∼+0.5 %/°C for −31 °C to +26 °C. Interaction of X-rays with a scintillation detector produces optical photons in the visible range. The spectral and spatial information of the X-ray can be derived by detecting these output photons using a Silicon Photomultiplier (SiPM). Two types of detector modules: CeBr 3 and NaI (Tl), coupled with an array of SiPM are presented here, which are being developed for the future space exploration programs. The development of the front end electronics (FEE) for the charge readout from SiPM for X-ray spectrometer application is presented here which is characterized for SiPM's over-voltages and shaping amplifier's time constant. In this article, both the detector modules are subjected to a wide temperature range to establish a relationship of the SiPM's gain, energy resolution and scintillators' output photon yield with ambient temperature. The test results show that energy resolution improves with higher over-voltage of SiPM and also with lower operating temperature. The gain of the SiPM array shows negative temperature dependence of ∼−0.81 %/°C for an over-voltage of 2.5 Volts. To derive the temperature dependency of scintillators' output photons, gain of the SiPM array was made constant by operating it at a fixed over-voltage for a wide temperature range. With the constant gain of SiPM, CeBr 3 scintillator shows negative temperature coefficient of ∼−0.27 %/°C and NaI (Tl) shows positive temperature coefficient of ∼+0.5 %/°C for the light output in the temperature range of −31 °C to +26 °C. [ABSTRACT FROM AUTHOR]

Quasi-zero-dimensional quantum dots (QDs) have garnered significant attention owing to their distinct structural attributes, quantum confinement behaviors, optoelectronic characteristics, etc. Regrettably, their susceptibility to stability poses a challenge. In this context, leveraging rational component regulation and crystallization process optimization strategies, we presented the successful preparation of CdS QDs silicate glass through the amalgamation of melt-quenching and controlled crystallization. The optical and morphological analysis substantiated the accomplishment of in-situ precipitation of CdS QDs within the glass matrix, with grain sizes <20 nm. Integrating CdS QDs into an inorganic glass matrix remarkably augmented its fluorescence thermal stability, enabling the preservation of 85.1 % of the room-temperature luminescent intensity even at an elevated temperature of 150 °C. Moreover, the encapsulated W-LED device by near-UV LED chip, CdS QDs glass, and BaMgAl 10 O 17 :Eu2+ phosphor exhibited a warm white-light emission characterized by suitable chromaticity coordinates (0.3741, 0.3452) and a notably high color rendering index (CRI = 93). Ultimately, the radioluminescence behavior of CdS QDs glass was unveiled by utilizing it as the scintillator wafer in an X-ray imaging system, which clearly demonstrated the structure of spring encapsulated within an opaque capsule. In a nutshell, these demonstrations unequivocally emphasize the substantial potential merits of CdS QDs glass, particularly in the domains of long-term W-LED lighting and X-ray imaging applications. [ABSTRACT FROM AUTHOR]

Er3+ doped high density germanate glasses with compositions of 50GeO 2 -10BaO–10Al 2 O 3 -15Lu 2 O 3 -(15-x) La 2 O 3 -xEr 2 O 3 (x = 0, 0.1, 0.5, 1.0, 1.5, and 2.0, in mol%) have been prepared by the melt-quenching method. The optical and physical properties of the samples were characterized by differential scanning calorimetry (DSC), density, transmittance spectra, photoluminescence (PL) spectra, and X-ray excited luminescence (XEL) spectra. The densities were in the range from 5.90 to 6.07 g/cm3. The strong green emissions around 552 nm of Er3+ were observed upon the excitations of 378 nm light and the X-ray, and the lifetimes of 552 nm emission were in the range of 20.88–96.47 μs. The results show that Er3+ doped high density germanate glasses could be used as potential scintillators for X-ray CT. [ABSTRACT FROM AUTHOR]

Commercial white light-emitting diodes (WLEDs) usually face problems such as lack of red emission, color difference caused by different degradation rates of multiphase phosphors and the poor thermal stability of the organic encapsulants. The development of new single-phase phosphors and glass can solve these problems well. Sr 3 B 14 O 24 :RE3+ (RE = Ce, Tb, Sm, Eu) phosphors and glass were synthesized by solid-phase method. The obtained Sr 3 B 14 O 24 :RE3+ (RE = Ce, Tb, Sm, Eu) samples showed multicolor emission including blue, green, orange and red, respectively. The optimal excitation wavelength of these samples was located in the blue or ultraviolet (UV) light regions, which were well matched with the blue-violet light chips to manufacture WLEDs. More interestingly, UV absorption was found in Sr 3 B 14 O 24 :Ce3+/4+ glass samples. The doping of dual-valence cerium ions could enhance the shielding performance in the light of inferences drawn from the UV-Vis absorption and transmission spectra of glass samples. By co-doping different concentrations of Cs+ ions in Sr 3 B 14 O 24 :Ce3+/4+ glass samples, the function of near infrared (NIR) shielding was also realized. As a new optical multifunctional material, rare earth doped Sr 3 B 14 O 24 have great potential for application in WLEDs, UV and NIR shielding. [ABSTRACT FROM AUTHOR]

Na 3 V 2 (PO 4) 3 (NVP) has attracted much attention due to its excellent potential for sodium storage property. However, low electronic and ionic conductivities severely limit further development. Herein, a dimensional gradient structure of Ce/Mo co-doped and carbon nanotubes (CNTs) enwrapped Na 3 V 2 (PO 4) 3 /C–CeO 2 @CNTs system is constructed by a facile sol-gel method for the first time. The much larger Ce3+ can be used as the pillar ions to buffer the crystal deformation and enhance the structural stability. Moreover, the high charge and strong self-polarization ability of Ce can suppress the increase of charge transfer resistance during the charge/discharge process, which is beneficial to improve the electrochemical performance. Meanwhile, the doping of high-valent Mo6+ generates beneficial vacancies to elevate the Na + diffusion kinetics. The presence of encapsulated CNTs inhibits particle growth, optimizing particle size and shortening ion delivery paths. Significantly, a new conductive CeO 2 phase is clearly identified combining with carbon layers to construct favorable bilayer conductive networks, which effectively facilitate electronic transport. Thus, the modified Na 3 V 1.79 Ce 0.07 Mo 0.07 (PO 4) 3 /C@CNTs (CeMo0.07@CNTs) exhibits a reversible capacity of 110.3 mAh g−1 at 1C, with 91% retention after 1000 cycles. It releases a capacity of 74.9 mAh g−1 at 30C and maintains at 73.9 mAh g−1 after 12000 cycles with a high retention rate of 98.7%. Furthermore, a high retention rate of 83.2% can be obtained after cycling 15000 cycles at 80C, corresponding to a low decay rate of 0.0011% each cycle. In addition, the CHC//CeMo0.07@CNTs asymmetric full cell reveals high specific capacity of 91.59 mAh g−1, demonstrating its excellent practical prospects. [ABSTRACT FROM AUTHOR]

Scintillators are used not only as single crystals in radiation detection systems but also as arrays, columns, and fibers. In this study, a novel optical-guiding crystal scintillator (OCS) was fabricated using an Eu:SrI 2 crystal as the core and borosilicate glass as the cladding. The OCS has an elongated shape and can be flexibly processed like an optical fiber. Furthermore, because inorganic scintillator crystals are used as the core, the OCS has high sensitivity to high-energy radiation, such as γ- and X-ray radiation, unlike plastic scintillators. In this study, by observing the cross section of the fabricated OCS, identifying the crystal structure, and investigating the radioluminescence spectrum under X-ray irradiation, OCS fabrication in accordance with the OCS design specifications was confirmed, and the SrI 2 crystal structure and Eu2+ 5d–4f luminescence were maintained. The γ-ray responses, such as light yield and decay time, were also investigated. [ABSTRACT FROM AUTHOR]

The Swarm satellite mission has been used for numerous studies of the ionosphere. Here we use a global product, based on electron density measurements from Swarm that characterises ionospheric variability. The IPIR (Ionospheric Plasma IRregularities product) provides characteristics of plasma irregularities in terms of their amplitudes, gradients and spatial scales and assigns them to geomagnetic regions. Ionospheric irregularities and fluctuations are often the cause of errors in position, navigation, and timing (PNT) based on the Global Navigation Satellite Systems (GNSS), in which signals pass through the ionosphere. The IPIR dataset also provides an indication, in the form of a numerical value index (IPIR index), of the severity of irregularities affecting the integrity of trans -ionospheric radio signals and hence, the accuracy of GNSS positioning. We analysed datasets from Swarm A and ground-based scintillation receivers. Time intervals (when Swarm A passes over the field of view of the ground-based GPS receiver) are compared to ground-based scintillation data, collecting an azimuthal selection of the GNSS data relevant to the Swarm satellite overpass. We provide validations of the IPIR product against the ground-based measurements from 23 ground-based receivers, focusing on GPS TEC and scintillation data in low-latitude, auroral and polar regions, and in different longitudinal sectors. We have determined the median, mean, maximum and standard deviation of the parameter values for both datasets and each conjunction point. We found a weak correlation of the intensity of both phase and amplitude scintillation with the IPIR index. [ABSTRACT FROM AUTHOR]

Novel scintillating and visualizing materials are an essential part of the development of high-power X-ray sources like synchrotrons and free-electron lasers. One of the latest approaches is the formation of composite materials composed of X-ray luminescent nanoparticles in a robust transparent matrix with high thermal conductivity. Here, such Sr 0.85-x Ba x Eu 0.15 F 2.15 nanopowders with a particle size of ≈50 nm were synthesized by precipitation from aqueous solutions. Single-phase solid solutions are formed up to a barium concentration of 70 mol.%. The most intense luminescence band is the band of trivalent europium with a maximum at 590.4 nm, corresponding to the 5D 0 → 7F 1 transition. The concentration dependence of the X-ray luminescence intensity on the barium content was revealed, and the most optimal composition Sr 0.35 Ba 0.50 Eu 0.15 F 2.15 with the brightest luminescence response was determined. The obtained type of nanoparticles has potential applications for the fabrication of new scintillating and visualizing composites. [ABSTRACT FROM AUTHOR]

The luminescence and scintillation properties of Ce3+ doped alkali phosphate glasses 56P 2 O 5 :8Gd 2 O 3 :5Al 2 O 3 :1CeBr 3 :30XCl (PGAC:X, X = Li/Na/K/Rb/Cs) were studied for their potential applications in gamma and alpha detection. In the Fourier Transform Infrared Spectroscopy (FTIR), X-ray Luminescence (XRL), Photoluminescence (PL), and transmittance spectra, the red shift was found and explained by the concept of optical basicity. Broad Ce3+ emission and energy transfer from Gd3+ to Ce3+ were observed in XRL and PL measurements. Scintillation performance was studied by irradiating the samples under 137Cs gamma and 241Am alpha sources. The fast, intermediate, and slow decay components under gamma and alpha excitation were found around 30, 200 and 3000 ns, respectively. The decay time increased slightly from PGAC:Li to PGAC:Cs, indicating the less effective transition from Gd3+ to Ce3+. The alpha decay time was longer than the gamma decay time, revealing the Pulse Shape Discrimination (PSD) capability of the glasses for particle identification. The XRL intensity reduced significantly from PGAC:Li to PGAC:Cs samples did not reflect the scintillation tendency. By successfully detecting gamma and alpha scintillation signals, the scintillation performance of all samples was found to be similar. In general, all samples can be used for gamma and alpha detection. Using Rb+ or Cs+ ions is favorable in terms of high density and light yield, while Li+ ions enhance the transmittance and homogeneity. Furthermore, a correlation between P–O–H groups within the glass matrix and scintillation performance was also observed. [ABSTRACT FROM AUTHOR]

This study investigated both the disturbance electric fields processes including the Interplanetary Electric Field (IEFy) to low-latitude, known as prompt penetration electric field (PPEF) and the disturbance dynamo electric field (DDEF), and their effects on ionospheric TEC and scintillations over south China during four storms of 17 March 2015, 15 July 2012, 7 October 2015 and 20 December 2015. GPS ionospheric and magnetometer data were derived from receiver stations at Guangzhou and Shenzhen, and at Guangdong Zhaoqin (GZH) and equatorial station Dalat, respectively. Results presented that cases of the eastward PPEF on dayside with durations of 3 and 8 h were identified during storm main phases of 17 March 2015 and of 20 December 2015 respectively. DDEFs were found to dominate on nightside during the three main storm phases other than storm of 15 July 2012, and on dayside during the recovery storm phase of 21 December 2015. The responses of positive TEC deviation to the eastward PPEF on dayside were identified during the storm main phase of 20 December 2015 rather than during the storm of 17 March 2015, which showed longitudinal, latitudinal and seasonal dependences as compared to the previous studies. During the storm of 15 July 2012, positive TEC deviations with no response to the eastward PPEF on dayside were identified. Negative TEC deviation responses to the DDEF on dayside were seen during all four storm recovery phases. GPS ionospheric scintillations (S 4 ≥ 0.4) dominated in the equinox months before the occurrences of four storms, but were inhibited during the storm of 17 March 2015 over south China, which was attributed to the inhibitions of irregularities caused scintillations. [ABSTRACT FROM AUTHOR]

The growth of the CsI(Tl) scintillators deposited on glass substrates with proper wavelength matching the mainstream semiconductor circuits is crucial for X-ray imaging industry. But the coupling loss between the scintillators and silicon based photo sensors has limited the performance. So fabricating CsI(Tl) films on monocrystalline silicon is greatly important for next-generation high performance X-ray image devices. However, the lattice and thermal mismatch between CsI(Tl) and Si always deteriorates the morphology and structure, and thus degrades the property of the CsI(Tl) scintillation converters. Here, by utilizing crystalline graphene(Gr) as a buffer layer, the van der Waals epitaxial growth of CsI(Tl) film on Si(111) substrate is reported and its advanced applications are demonstrated. The introduced graphene buffer layer extremely frees the stress between CsI(Tl) and Si substrate. Therefore, the CsI(Tl) films show perfect micro-columnar and crystalline structures, and then, exhibit much higher light output and signal to noise ratio, and better modulation transfer functions and a bar pattern X-ray image compared to that on bare Si(111) substrate. This facile method not only lays the foundation for the epitaxy of the alkali halide crystals, including CsI(Tl), onto Si-based detectors and its applications in radiation detection, but also may broaden a new perspective of deposition of CsI(Tl) scintillators into flexible substrates. [ABSTRACT FROM AUTHOR]

In recent years, researchers have been attracted to the tuning of the solar spectrum through a coverglass as a means to enhance the efficiency of a photovoltaic cell by improving the energy transfer mechanism. In this study, energy transfer mechanism was investigated between Gd 3 + and Ce 3 + ions in a bismuth borate glass. Cerium ions (0.1–2.5 mol%) were doped into a bismuth borate glass using a versatile melt-quenching technique in an ambient atmosphere under various experimental conditions. The luminescence and optical properties were examined in relation to the concentration of cerium. The structural changes in the glass matrix that occurred as a result of variation in the concentration were investigated using Fourier transform infrared spectroscopy. To ensure the incident light passage through the glass is not compromised due to self-absorption, optical absorption measurements were carried out to investigate the presence of resonant plasmonic absorption of nanoclusters. The energy bandgap of Ce 3 + -doped glass decreased from 2.772 to 2.671 eV due to dopant concentration-induced structural change in the glass matrix. The photoluminescence properties of the present samples confirmed their suitability for luminescent down converter applications. At UV excitation wavelength of 325 nm, the Ce 3 + -doped samples down-shifted the solar spectrum and gave the most prominent emission band at 448 nm due to the 5d-4f transition of Ce 3 +. The optimum concentration was observed as 0.3 mol%, further increase in the dopant concentration led to a decrease in the emission intensity may be due to the conversion of Ce 4 + into Ce 3 + ions [47,48]. In the energy transfer, Gd 3 + transfers energy non-radiatively to Ce 3 + due to the equivalent energy level 6 P 7 / 2 of Gd 3 + and 5d energy level of Ce 3 +. • Investigated energy transfer between Gd 3 + and Ce 3 + ions in bismuth borate glass • Cerium ions (0.1-2.5 mol%) doped using versatile melt-quenching technique • Ce 3 + -dopant concentration reduced energy bandgap to 2.671 eV • Ce 3 + -doped samples down-shifted solar spectrum, emitted at 448 nm • Optimum dopant concentration observed at 0.3 mol%, higher led to quenching [ABSTRACT FROM AUTHOR]

The objective of this paper is to review the use of the thermoluminescence (TL) and optically stimulated luminescence (OSL) techniques as research tools in luminescence, particularly to detect the presence of trapping centers that can degrade the efficiency of scintillators, and shape the properties of persistent phosphors, storage phosphors and dosimeters. A brief review of the main analysis techniques is provided, followed by a discussion of their limitations. Examples of applications in which the TL or OSL analyses have provided useful information on the trapping and recombination of charges created by ionizing radiation is given. [ABSTRACT FROM AUTHOR]

Scintillator glasses have the potential for X-ray imaging owing to their low production cost, controllable shape and size, and uniform ion-doping concentration. In this study, Tb3+-doped and Ce3+/Tb3+-co-doped oxyfluoride scintillator (C4T9) glass samples were fabricated by high-temperature melting and quenching. In addition, the luminescence properties of the glass samples and the discrepancy in the energy transfer mechanism between Ce3+ and Tb3+ under ultraviolet (UV) light and X-ray excitation were investigated. The C4T9 glass sample showed excellent integral scintillation efficiency of 84.1% for commercial Bi 4 Ge 3 O 12 (BGO) crystals. The spatial resolution of the C4T9 glass sample was higher than that of the commercial BGO crystal with 42.29 mGy s−1 X-ray irradiation, reaching 16 lp·mm−1. C4T9 glass is expected to become a key material in medical imaging, safety inspection, industrial inspection, and other fields. [ABSTRACT FROM AUTHOR]

Micron/sub-micron hard X-ray imaging is an important development direction of X-ray detection technology. Scintillation screens with excellent X-ray stopping power and high light output are desired to obtain good imaging quality. Europium-doped lutetium oxide (Lu 2 O 3 :Eu) film with micro-columnar structure is an ideal candidate for this application. In this study, micro-columnar structured Lu 2 O 3 :Eu films were prepared on quartz glass substrates by laser chemical vapor deposition (LCVD) method. The influences of preparation conditions on structure and morphology properties of films were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Photoluminescence and scintillation properties of the films, including photoluminescence excitation (PLE), photoluminescence (PL), PL decay, X-ray excitation luminescence (XEL), and afterglow curves, were recorded. The relationships between structure, morphology, luminescence properties of films, and preparation conditions were investigated and discussed as well. The preparation conditions include laser power, oxygen flow rate, and precursor evaporation temperature. In addition, dual-layer Lu 2 O 3 :Eu film was prepared for the first time by just turning off the laser. [ABSTRACT FROM AUTHOR]

The study deals with the use of different amounts of MgO or tetraethyl orthosilicate (C 8 H 20 O 4 Si, TEOS), from 0.04 wt %, 0.06 wt %, 0.08 wt %, 0.4 wt %, 0.6 wt % to 0.8 wt %, respectively, as additional sintering aids during the vacuum sintering of transparent Ce3+ doped Y 3 Al 5 O 12 (Ce:YAG) ceramics to investigate their effect on microstructure and luminescence properties. A comparative study was carried out by using X - ray diffraction, scanning electron microscopy/energy dispersive X - ray spectroscopy, optical and photo-luminesce spectra, as well as electroluminescent spectra. The dominant garnet phase was obtained even when adding 0.8 wt % of MgO or TEOS, while adding MgO led to finer average grain size (∼ 5 - 10 μm) and more homogenous distribution compared to TEOS (∼ 20 - 25 μm) in Ce:YAG ceramics. Adding a large amount of MgO was found to result in the segregation of MgO in Ce:YAG ceramics, while an excess of TEOS led to the segregation of Al 2 O 3. A strong absorption peak at 308 nm was observed in Ce:YAG ceramics with MgO sintering aids, which was ascribed to the existence of Ce4+ induced by a charge compensation effect of Mg2+. The optimum transmittance reached 80% @ 800 nm in Ce:YAG ceramics when adding 0.6 wt % TEOS, which also exhibited a maximum luminous efficacy of 106 lm/W. Si4+ was experimentally proved to have a better optimization effect on luminous efficacy compared to Mg2+. • MgO or TEOS (C 8 H 20 O 4 Si) was added as additional sintering aids in a wide amount range. • MgO proves to have distinct inhibit effect on the grain growth. • Better luminous efficacy were observed in ceramics with TEOS additives. [ABSTRACT FROM AUTHOR]

Compared with single-crystal scintillator, the glass scintillators have the benefits of low cost, big size, straightforward manufacturing method, and adjustable component. In this work, a succession of diaphanous gallogermanate glass scintillators doped with Tb3+ or Eu3+ were manufactured using melt-quenching technique. The thermal, structural, photoluminescent, and scintillating properties were studied. For photoluminescent properties, 12 mol% Tb3+-doped glass sample has high internal quantum efficiency (87.8%) and no obvious concentration quenching phenomenon can be observed. For scintillating properties, the optimal doping concentration of Tb3+ and Eu3+ are 4 mol% and 8 mol%, respectively. The integral intensity of X-ray excited luminescence of Tb3+-doped sample is 73.1% of that of Bi 4 Ge 3 O 12 scintillator, while the ratio of Eu3+-doped sample is 26.5%. The radiation damage of 4 mol% Tb3+-doped sample resulted by high power X-ray could be repaired through heat-treatment, while 8 mol% Eu3+-doped sample exhibits fine stability that the transmittance keeps constant after exposed to high power X-ray. Our research indicates Tb3+ or Eu3+ doped gallogermanate glass might be candidate for X-ray detection of slow events. [ABSTRACT FROM AUTHOR]

Pr3+ doped high density germanate glasses were prepared by the melt-quenching method. The physical and luminescent properties were investigated. The glass containing BaF 2 represented maximum phonon energy of 810 cm−1, and the glass density was greater than 6 g/cm3. The glass exhibited good radiation resistance under 2 h of X-ray irradiation. Intense blue, green emissions and weak red emissions were observed when the glass was excited by X-ray, and the blue fluorescence lifetimes were in the range of 9.15–12.59 μs The results show that Pr3+ doped germanate glass could be a potential scintillating material in the field of X-ray detection for fast events. [ABSTRACT FROM AUTHOR]

Non-invasive phototherapy has been emerging as an ambitious tactic for suppression of amyloid-β (Aβ) self-assembly against Alzheimer's disease (AD). However, it remains a daunting challenge to develop efficient photosensitizers for Aβ oxygenation that are activatable in a deep brain tissue through the scalp and skull, while reducing side effects on normal tissues. Here, we report an Aβ targeted, low-dose X-ray-excitable long-afterglow scintillator (ScNPs@RB/Ab) for efficient deep-brain phototherapy. We demonstrate that the as-synthesized ScNPs@RB/Ab is capable of converting X-rays into visible light to activate the photosensitizers of rose bengal (RB) for Aβ oxygenation through the scalp and skull. We show that the ScNPs@RB/Ab persistently emitting visible luminescence can substantially minimize the risk of excessive X-ray exposure dosage. Importantly, peptide KLVFFAED-functionalized ScNPs@RB/Ab shows a blood–brain barrier permeability. In vivo experimental results validated that ScNPs@RB/Ab alleviated Aβ burden and slowed cognitive decline in triple-transgenic AD model mice at extremely low X-ray doses without side effects. Our study paves a new pathway to develop high-efficiency transcranial AD phototherapy. Non-invasive phototherapy has been emerging as an ambitious tactic for suppression of amyloid-β (Aβ) self-assembly against Alzheimer's disease (AD). However, it remains a daunting challenge to develop efficient photosensitizers for Aβ oxygenation that are activatable in a deep brain tissue through the scalp and skull, while reducing side effects on normal tissues. Herein, we report an Aβ targeted, low-dose X-ray-excitable long-afterglow scintillators (ScNPs@RB/Ab) for efficient deep-brain phototherapy. In vivo experimental results validated that ScNPs@RB/Ab alleviated Aβ burden and slowed cognitive decline in triple-transgenic AD model mice at extremely low X-ray doses without side effects. [Display omitted] [ABSTRACT FROM AUTHOR]

In recent years, copper-based halide scintillators have attracted tremendous attention due to their excellent luminescent properties and low manufacturing costs. Herein, a high-performance and low-cost Cs 5 Cu 3 Cl 6 I 2 scintillator is prepared by simple mechanical grinding. The mixed-halide Cs 5 Cu 3 Cl 6 I 2 phosphor exhibits a blue emission centered at 475 nm with a large stokes shift, originating from the self-trapped exciton emission of Cu sites. The photoluminescence quantum yield (PLQY) of Cs 5 Cu 3 Cl 6 I 2 can be increased to 88.4% from 20.4% by the efficient suppression of the anion vacancy defects. In addition, the Cs 5 Cu 3 Cl 6 I 2 scintillator shows a high steady-state X-ray to light conversion efficiency of about 57000 photons/MeV, good X-ray linear response, and low detection limit of 71.9 nGy air /s. The X-ray imaging results based on the Cs 5 Cu 3 Cl 6 I 2 scintillator screen display a high spatial resolution of 9.0 line-pairs per millimeter (lp/mm). Furthermore, Cs 5 Cu 3 Cl 6 I 2 exhibits good radiation stability under a total dose of 113.58 Gy air. Overall, the Cs 5 Cu 3 Cl 6 I 2 scintillator prepared by mechanical grinding method has the advantages of low cost, high efficiency, and good radiation resistance, suggesting its huge potential in X-ray detection and imaging. [ABSTRACT FROM AUTHOR]

[Display omitted] • B-site co-doped perovskite nanocrystals were synthesized. • Co-doped NCs has excellent photoluminescence efficiency and lifetime. • The mechanism of enhanced luminescence of co-doped NCs was elucidated. • The stable scintillator film was prepared by PVDF-HFP encapsulation of co-doped NCs. • The film has excellent performance as scintillator under X-ray. Perovskite scintillators with low cost, easy preparation, environmental stability, and high-resolution have become candidates for X-ray imaging applications. Here, based on the calculation results of surface formation energy (E f) and vacancy defect energy (E vac), a series of co-doped perovskite nanocrystals (NCs) with photoluminescence high quantum yield (PLQY) and fast luminescence decay time had been prepared by doping several bivalent metal ions into the B-site of methylammonium lead tribromide (MAPbBr 3). In addition, the scintillator with flexibility was prepared using poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) as the carrier, showing excellent stability and scintillation performance, with a light yield of 21,200 photons/MeV, imaging resolution reached 11.7 lp/mm, and low detection limits of 462 nGy air s−1. Finally, we demonstrated the scintillator characteristic with high-quality imaging results and excellent tolerance under high dose rate X-ray (25 mGy s−1). Therefore, the combination of co-doped nanocrystals with excellent optical properties and PVDF-HFP further paves the way for the development of a scintillator. [ABSTRACT FROM AUTHOR]

[Display omitted] • Organic cuprous clusters were synthesized by antisolvent vapor-assisted crystallization. • Photoluminescence was tunable by adjusting ratio of raw materials due to vacancy defects changing. • Two charge transfer paths exist in the IPPCuI 2. • Superior X-ray scintillation performances exhibit in DR and CT. • Single-component WLED based on IPPCuI 2 has high CRI and stability. Low-dimensional cuprous clusters demonstrate fascinating luminescent properties due to their uniquely diversified charge transfer excited states, which imply it could be ideal candidate for multifunctional applications, such as X-ray scintillators and white light emitting diodes (WLED). However, it is still challenge for low-dimensional cuprous clusters that how to regulate the emission performance to meet the requirements of the specific applications. In this work, we prepared a series of luminescent organic cuprous iodide clusters, (IPP)CuI 2 and (IPP) 2 CuI 3 , which show tunable emission property by simply component regulation. The (IPP)CuI 2 with IPP: CuI = 1: 0.75 show the best scintillator property with super-low detection limit of 62.29 nGy/s and high light yields of 75793.83 photons/MeV which is far beyond most organic copper halide scintillators. A series of clear digital radiography (DR) with high spatial resolution of 10.2 lp/mm and a reconstructed 3D model based on computed tomography (CT) were successfully obtained by the prepared scintillation screen. Moreover, the single-component WLED based on accurately component regulation (IPP)CuI 2 with IPP: CuI = 1: 0.99 exhibits pure white emission with a high CRI (color rendering index) of 82. The luminescence mechanism of charge transfer excited states in tunable emission (IPP)CuI 2 was also investigated. Our works not only provide a kind of ideal materials applied for high-performance single-component WLED and scintillator but also reveal the large potential of low-dimensional organic cuprous halides as luminescent material for multifunctional applications. [ABSTRACT FROM AUTHOR]

Particle dark matter could belong to a multiplet that includes an electrically charged state. WIMP dark matter (χ 0) accompanied by a negatively charged excited state (χ −) with a small mass difference (e.g. < 20 MeV) can form a bound-state with a nucleus such as xenon. This bound-state formation is rare and the released energy is O (1 − 10) MeV depending on the nucleus, making large liquid scintillator detectors suitable for detection. We searched for bound-state formation events with xenon in two experimental phases of the KamLAND-Zen experiment, a xenon-doped liquid scintillator detector. No statistically significant events were observed. For a benchmark parameter set of WIMP mass m χ 0 = 1 TeV and mass difference Δ m = 17 MeV, we set the most stringent upper limits on the recombination cross section times velocity 〈 σ v 〉 and the decay-width of χ − to 9.2 × 10 − 30 c m 3 / s and 8.7 × 10 − 14 GeV, respectively at 90% confidence level. [ABSTRACT FROM AUTHOR]

CYGNO is an international collaboration with the aim of operating a ▪ optical time projection chamber (TPC) for directional Dark Matter (DM) searches and solar neutrino spectroscopy, to be deployed at the Laboratori Nazionali del Gran Sasso (LNGS). A ▪/▪ (60/40) mixture is used, along with a triple Gas Electron Multiplier (GEM) cascade to amplify the ionisation signal. The scintillation produced in the electron avalanches is read out using a scientific complementary metal–oxide–semiconductor (sCMOS) camera. This solution has proven to provide very high sensitivity to interactions in the few ▪ energy range. The inclusion of a hydrogen-based gas will offer an even lighter target, resulting in a more efficient energy transfer in a DM particle collision, and consequently, a lower detection threshold. Additionally, longer track lengths of light nuclear recoils are easier to detect with a clearer direction. However, the addition of such gas will contribute to quenching the scintillation, jeopardizing the TPC performance. In this work, we demonstrate the feasibility of adding 1% to 5% isobutane to the ▪/▪ (60/40) mixture by measuring the respective absolute scintillation yield output. The overall scintillation produced in the charge avalanches is not drastically suppressed by quenching due to the isobutane addition. The presence of Penning transfer from excited He atoms to isobutane molecules increases the number of electrons in the avalanches, partially compensating for the loss of scintillation due to quenching. For the highest applied GEM voltage, the total number of photons produced in the avalanche per ▪ deposited in the absorption region presents a decrease of only a factor of about three, from 2.30 (20) × 10 4 to 8.2 (4) × 10 3 ▪, as the isobutane content increases from 0 to 5%. The quantification of the visible component of the scintillation shows that isobutane quenches both visible and ultraviolet (UV) photons emitted by ▪/▪. [ABSTRACT FROM AUTHOR]

A simple method of in-situ growth using anodized aluminum oxide templates is used to prepare a high-resolution pixelated scintillator array Cs 5 Cu 3 Cl 6 I 2 with enhanced light direction limitation for X-ray imaging, The Cs 5 Cu 3 Cl 6 I 2 @AAO film performs excellent stability under long-term X-ray irradiation, making it a reliable option for cost-effective pixelated indirect X-ray imaging. [Display omitted] • A perovskite array scintillation film Cs 5 Cu 3 Cl 6 I 2 @AAO via an in-situ growth strategy was fabricated. • A spatial resolution of approximately 20 lp mm−1 and a detection limit of 0.152 μGy·s−1 were achieved. • Excellent stability under long-term X-ray irradiation of Cs 5 Cu 3 Cl 6 I 2 @AAO was studied. Lead-free halide perovskites have shown promising application for indirect X-ray detection as fascinating scintillator. The fabrication of pixelated scintillator films leveraging directional confinement allows high-resolution imaging, yet process complexity and the potential crystal structure damage pose challenges that compromises the corresponding scintillator performance. In this work, a facile in-situ strategy for growing scintillation perovskite of Cs 5 Cu 3 Cl 6 I 2 within anodic aluminum oxide (AAO) membrane is developed as scintillator Cs 5 Cu 3 Cl 6 I 2 @AAO film. The as-fabricated pixelated scintillator array with an enhanced light directional confinement for high-resolution X-ray imaging is demonstrated. The corresponding film achieves a spatial resolution of approximately 20 lp mm−1 and a detection limit of 0.152 Gy·s−1. Moreover, the Cs 5 Cu 3 Cl 6 I 2 @AAO film performs excellent stability under long-term X-ray irradiation, making it a reliable option for cost-effective pixelated indirect X-ray imaging. [ABSTRACT FROM AUTHOR]

[Display omitted] • MAPbBr 3 NCs are in-situ space-confined encapsulated in metal–organic frameworks. • bMOF⊃MAPbBr 3 realizes room-temperature scintillation and exceptional X-ray imaging. • bMOF⊃MAPbBr 3 shows enhanced stability against various stimuli and X-rays. • The role of the MOF and the mechanism of improved performance are elucidated. The development of perovskite nanocrystals (NCs) based composites with enhanced stability and exceptional photoelectric properties is of great significance for their application in scintillators for X-ray imaging, but it remains challenging. Herein, we demonstrate a novel and stable scintillator, achieved through a host–guest strategy involving the confinement of perovskite NCs, e.g., MAPbBr 3 NCs, in metal–organic frameworks (MOFs). The host MOF, bio-MOF-100 (denoted as bMOF), facilitates the in-situ space-confined formation of MAPbBr 3 NCs while providing quantum confinement, surface passivation, and protection to these guests. This host–guest strategy results in high exciton binding energy, bright and efficient luminescence, and significantly enhancing their stability against various factors such as air, heat, UV, solvents and X-ray irradiation. Consequently, this advancement prompts the transition of their application scenarios from the colloidal state to the solid state. The bMOF⊃MAPbBr 3 scintillator exhibits a linear response to X-ray with a detection limit determined to be 170 nGy air s−1. Moreover, the bMOF⊃MAPbBr 3 –PMMA scintillator screen demonstrates high-quality X-ray imaging with an impressive spatial resolution of 14.7 lp mm−1. This work provides a new avenue for the development of perovskite NCs-based host–guest composites and paves the way for the broader implementation in solid-state optoelectronic applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new 3D organic supramolecule constructed by unique halogen bonding and π–π interactions is obtained. • Dual phosphorescent emission mechanism of the supramolecule is explained. • This supramolecule shows highly stable UOP property that can be applied directly in extreme environments. Ultralong organic phosphorescence (UOP) materials have offered new exciting possibilities in the fields of photoelectric device, scintillators, anti-counterfeiting and bioprobe. However, pure organic phosphorescent materials inevitably suffer from rapid nonradiative transitions under oxygen, humidity, and high temperature, rending their phosphorescence is significantly quenched. Herein, a three-dimensional (3D) organic supramolecule (named SFIz) featuring UOP property was constructed successfully. Impressively, benefiting from the unique halogen bonding and π–π interactions, dual phosphorescent emission route of high energy state T 1 (Br···O interaction predominates) and low energy state T 1 * (π–π interaction predominates) was simultaneously realized. Furthermore, owing to the robust supramolecular structural characteristic, SFIz shows highly stable UOP property with remarkably thermal, force stimulus and water-resistant stabilities that can be applied directly in extreme environments such as high temperatures 453 K (180 °C), high pressure and humidity. This work not only provides a much needed solution for achieving highly stable UOP materials and promoting their applications in extreme environments, but also gives in-depth understanding of both UOP and dual phosphorescent emission mechanisms in a non-metallic organic molecule. [ABSTRACT FROM AUTHOR]

This paper presents a study on the salinity determination and flow rate estimation in a two-phase air-water system. For this purpose, an automated air-water test loop capable of generating different flow patterns in a horizontal pathway was utilized to do numerous experiments at varying flow rates. A nuclear measuring setup, comprising Cs-137 and Am-241 as radiation sources, one NaI (Tl) scintillation detector to register transmission counts of Cs and three scintillator detectors for registering transmission and scattering counts from Am, was prepared. A pressure drop pipe was also employed for flow rate measurement, with MLPs were selected as the processing element. Notable innovations of this paper can be considered from two perspectives. Firstly, a novel paradigm in nuclear measurement geometry. This novelty uses the benefits of three scintillator detectors to extract features with the maximum potential for classifying and determining salinity. Secondly, there is a new method in data processing and utilizing optimum features to achieve the best performance in predicting flow rates. Results in flow rate prediction independent of salinity and flow regime indicate that the proposed paradigm and method are reliable for using in industrial fields related to multi-phase metering. • This paper proposes a novel paradigm in nuclear measurement geometry. • This paper employs seven ANNs to develop the optimal prediction model. • The combination of wavelet transform and statistical features shows the best performance to determine the flow rates. • The results indicated that the proposed prediction model achieved an MAE of less than 4/237 L/min and an MRE% of 4/842 % for predicting flow rates. [ABSTRACT FROM AUTHOR]

A new scintillator based fast-ion loss detector (FILD) system has been designed for the Wendelstein 7-X (W7-X) stellarator. The mechanical design of the system is presented here along with engineering analyses of the system. This includes an assessment of the structural loads which also considers electromagnetic forces calculated for possible disruption scenarios as well as a mode frequency analysis of the system. Furthermore, an analysis of the thermal characteristics of the actively cooled probe head under prescribed steady state and transient heat loads is presented. Finally, the optical relay system is described and its properties used to forward model synthetic camera signals using the FILDSIM code and based on theoretical fast-ion losses incident on the probe head calculated using the ASCOT5 code. [ABSTRACT FROM AUTHOR]

• The neutron energy response of Cs 2 7LiYCl 6 :Ce (CLYC-7) scintillation detector was investigated, and the figures-of-merit (FOM), response function, and neutron energy resolution at different neutron energies were obtained. • The Monte Carlo method was used to simulate the particle transport within the CLYC-7 scintillator and investigate the energy response curves of different particles. • The response function was applied to the CLYC-7 scintillation detector, and it was used to measure the D-D fusion neutron spectrum on EAST. During plasma experiments on EAST (Experimental Advanced Superconducting Tokamak), the discharges heated with neutral beam injection (NBI) for plasma results in the production of 2.45 MeV deuterium-deuterium (D-D) fusion neutrons. In order to measure the energy spectrum of D-D fusion neutrons, a new Cs 2 7LiYCl6:Ce (CLYC-7) crystal with 7Li-enrichment has been developed and fabricated into a CLYC-7 scintillation detector. Before utilizing this detector for studying neutron energy spectra, it is crucial to explore the response function of the detector within a relevant neutron energy range. Therefore, the detector has been experimented using the 4.5 MeV electrostatic accelerator at Peking University to investigate its response to fast neutrons, energy resolution, and pulse discrimination capability in the neutron energy range 2.07 MeV–5.51 MeV. The neutron reactions occurring within the CLYC-7 scintillator were simulated using MCNPX, focusing on the reactions 35Cl(n,p) and 35Cl(n,α), as well as the energy response curve and the contributions of different particles (protons, alphas) to the neutron spectrum. The experimental results were successfully validated on EAST, where the 2.45 MeV fusion neutron energy spectrum was measured. That demonstrates the ability of the CLYC-7 scintillation detector to diagnose the fusion neutron energy spectrum for deuterium plasma discharge. [ABSTRACT FROM AUTHOR]

Lead-free Cs 3 Cu 2 Cl 5 metal halide exhibits high photoluminescence quantum yield (PLQY), large Stokes shifts and small self-absorption due to self-trapped excitons (STE) emission, which undoubtedly is a potential scintillator material. However, Cs 3 Cu 2 Cl 5 nanocrystals (NCs) are susceptible to degradation by moisture at high humidity environment, which severely affects its long-term application in X-ray imaging. Herein, we prepared Cs 3 Cu 2 Cl 5 scintillator films with a PLQY of 72.4% and a high spatial resolution of 20 lp mm−1. Moreover, we firstly propose a self-healing strategy with facile microwave treatment to recover the crystal structure of Cs 3 Cu 2 Cl 5 film which damaged by moisture, while the photoluminescence (PL) and radioluminescence (RL) intensities of the damaged Cs 3 Cu 2 Cl 5 film are repaired to more than 95% and the spatial resolution can be restored to 20 lp mm−1. Furtherly, the imaging quality of the self-healing scintillator film can be maintained stably by cyclic microwave treatment. It found that microwave treatment provides a simultaneous and molecular level heating environment for the Cs 3 Cu 2 Cl 5 film, which drives the hydrolysates to re-crystallize along with the surface of the destroyed crystals. Therefore, microwave treatment opens a new avenue to recover Cs 3 Cu 2 Cl 5 films degraded by moisture, and provides a solution for long-term application of scintillator films at low cost. [ABSTRACT FROM AUTHOR]

Among the aluminate garnet materials, cerium-doped gadolinium gallium aluminum garnet ceramics (GGAG:Ce) show fast scintillation properties, which suggests that they have promising applications in medical imaging, high-energy ray detection and high-power LED lighting. In this study, Gd 3 Ga 3 Al 2 O 12 :Ce scintillation ceramics co-doped with Me2+ (Me = Mg, Ca) are fabricated using a two-steps route: a solid-state reaction followed by annealing in air. The optical and scintillation properties, including the absorption, radio luminescence (RL), light yield, and decay time, of these co-doped ceramics are studied in detail. Doping with Mg2+ and Ca2+ leads to the oxidation of Ce3+ to Ce4+, which accelerates the scintillation process and decreases the light yield. Co-doping with Ca2+ and Mg2+ shows a synergistic effect on this phenomenon. Compared with 0.2 at% Ca2+ or 0.2 at% Mg2+ single-doped GGAG:Ce, the GGAG:Ce co-doped with 0.1 at% Ca2+ and 0.1 at% Mg2+ has the fastest decay time (∼31 ns) and maintains a relatively high light yield (∼27400 ± 1600 ph/MeV, 77% of undoped GGAG:Ce). These findings shed new light on designing Ce-activated garnet scintillator materials with ultra-fast decay time for applications in time-of-flight (TOF) PET technology. [ABSTRACT FROM AUTHOR]

Recently, novel transparent and fluorescent materials are in demand for various optical applications such as lasers, scintillators, and solid-state lighting. α-SiAlON, which has excellent thermal and mechanical properties, also exhibits photoluminescence depending on the stabilized doped rare-earth ions. Its transparency and fluorescence depend on the rare-earth oxide added as a raw material, particularly in conventional powder processing. In this study, we fabricated α-SiAlON ceramics by adding various rare-earth oxides to elucidate their effects on the transparency and fluorescence of these ceramics. High-transparency α-SiAlON ceramics were fabricated by adding rare-earth oxides whose rare-earth ions have small ionic radii: Y 2 O 3 , Ho 2 O 3 , Er 2 O 3 , Tm 2 O 3 , Yb 2 O 3 , and Lu 2 O 3. Because the fraction of α-SiAlON was high, the relative density was high, and the microstructure was composed of fine grains. In particular, α-SiAlON ceramics prepared by adding Ho 2 O 3 showed lower light scattering than the other fabricated α-SiAlON ceramics because of the smaller α-SiAlON grains, resulting in higher in-line transmittance (48% at 600 nm). Furthermore, these transparent α-SiAlON ceramics exhibited fluorescence corresponding to the activated rare-earth ions: Ho3+, Er3+, Tm3+, and Yb3+ or Yb2+. [ABSTRACT FROM AUTHOR]

The ability of a scintillator to absorb and convert the high-energy X-ray photons to low-energy visible photons is crucial for the application of X-ray in medical tests, security checks and scientific research. However, traditional scintillation crystals are synthesized by complex preparation process with high cost, hindering the wide development in practical applications. Here, Tb3+ doped sodium silicate glass, which exhibits remarkable scintillation property and recoverability to X-ray irradiation, was successfully prepared by an exercisable melt-quenching method. The obtained scintillator shows intense radioluminescence, which is about 1.5 times higher than that of the reference of Bi 4 Ge 3 O 12. The damaged glass to X-ray irradiation can be returned to the original state after heat treatment again, indicating excellent recovery. Moreover, the scintillator displays wonderful thermal stability with the fluorescence intensity at 573 K still remaining 96% at room temperature. These results demonstrate that the obtained scintillating glass has potential application towards the real world. [ABSTRACT FROM AUTHOR]

lthough single crystal scintillators have excellent performance, they have some drawbacks such as high cost, complicated elaboration method and difficulty of growth on large-scale. Glass scintillators are widely investigated to replace single crystal scintillators because of their simple fabrication method and low cost. In this paper, a series of transparent borosilicate aluminate glass scintillators doped with Tb3+ were successfully prepared by traditional melt-quenching method. The structural, luminescent, and X-ray excited scintillating properties were investigated. These glass samples show high stability and high transparency, and present good luminescent and scintillating properties. Sample with Tb3+ doping concentration of 10% has the best scintillating performance. The integrated intensity of X-ray excited luminescence is 66.6% of that of commercial Bi 4 Ge 3 O 12 single crystal scintillator, and the quantum efficiency (under 378 nm excitation) is 70.3%. Our findings suggest that Tb3+-doped borosilicate aluminate glasses with high light yield might be used as potential scintillators. [ABSTRACT FROM AUTHOR]

Recent surge in additive manufacturing efforts demonstrate stereolithography as a promising technique for fabricating glass materials due to the high speed and scalability of the process. However, little efforts have been devoted to manufacture borosilicate glass by the stereolithographic process. One of the challenges is that its relatively low softening temperatures could interfere with the thermal post-printing process and introduce poor fidelity and structure instability. Here, we report on the first demonstration of stereolithographic manufacturing of cerium-doped (Ce-doped) (<10%) and undoped borosilicate glass which was enabled by a multi-step post thermal processing. The optical properties of the printed glass depend on thermal processing parameters (temperature, time, and environment) and can be readily tuned and optimized for a wide range of applications. The printed amorphous glass shows good structural stability with band gap of 3 eV, Urbach energy of 0.75 eV and refractive index of 2.14 for 8% Ce-doped glass, respectively. These results indicate Ce-doped glass fabricated by stereolithography is suitable for scintillator applications and that additive manufacturing could be promising for borosilicate glass fabrication. [ABSTRACT FROM AUTHOR]

Optical, scintillation, and thermally and optically stimulated luminescence (TSL and OSL) properties of the undoped and Mn-doped MgGa 2 O 4 single crystals were investigated. All the crystals showed a luminescence peak at 500 nm caused by the 3d–3d transitions of Mn2+. The 0.03 %-Mn-doped crystal exhibited the highest OSL intensity, whereas the 0.3 %-Mn-doped crystal exhibited the highest photoluminescence quantum yield and scintillation intensity. There was an inverse relationship between the scintillation and OSL intensity in the 0.03–0.3 % Mn-doped crystals. The results indicated that the 0.03 % Mn-doped crystal exhibits the highest efficiency during carrier trapping. In the OSL dose response functions, the lower detection limit of the 0.03 % Mn-doped crystal was 0.01 mGy, which was comparable with that of a commercial product. • Optical, scintillation, and dosimetric properties of Mn-doped MgGa 2 O 4 single crystals were investigated. • The crystals showed the luminescence due to 3d-3d transitions of Mn2+. • The 0.03 % Mn-doped MgGa 2 O 4 single crystal showed the highest OSL intensity, and the detection limit was better than that of a commercial dosimeter. [ABSTRACT FROM AUTHOR]

Inch-sized Mn-based halide single crystal films, (C 25 H 22 P) 2 MnCl 4 and (C 25 H 22 P) 2 MnBr 4 , with tunable thickness from 0.12 mm to 0.72 mm were designed and used directly in the X-ray imaging. The high light yield of 56,457 and 78,937 photons/MeV and high spatial resolution exceeding 20 lp/mm demonstrates the great potential of large size single crystal scintillator screen for commercial high-resolution X-ray imaging applications. [Display omitted] • Inch-sized Mn-based halide single-crystalline films with tunable thickness from 0.12 mm to 0.72 mm were designed and grown. • The inch-size single crystals of (C 25 H 22 P) 2 MnCl 4 and (C 25 H 22 P) 2 MnBr 4 exhibit high light yield of 56457 and 78937 photons/MeV under X-rays. • The (C 25 H 22 P) 2 MnCl 4 and (C 25 H 22 P) 2 MnBr 4 single crystal screens exhibit outstanding spatial resolution of 21.02 and 25.61 lp/mm. Hybrid metal halides are emerging candidates for X-ray imaging. Due to the poor uniformity, low transmittance and high light scattering of polycrystalline film scintillator screen, resulting in low resolution of X-ray imaging, it is essential a challenging to explore new large-area and single crystal scintillator with high light yield and high resolution. Herein, inch-sized Mn-based halide single crystals, (C 25 H 22 P) 2 MnCl 4 and (C 25 H 22 P) 2 MnBr 4 , with tunable thickness films from 0.12 mm to 0.72 mm were designed and grown. The crystals of (C 25 H 22 P) 2 MnCl 4 and (C 25 H 22 P) 2 MnBr 4 with high photoluminescence quantum yield (PLQY) of 62.42 % and 99.10 % exhibit high light yield of 56,457 and 78,937 photons/MeV under X-ray, which is 1.7 and 2.37 times higher than that of the commercial LYSO scintillator. Both the crystals show high X-ray radiation resistance even exposed to X-ray for 60 mins with a high dose rate of 504 mGy s−1. The high photochemical stability under the continuous UV and X-ray irradiation contributes them towards X‑ray imaging. With such significant merits, the high spatial resolutions about 21.02 and 25.61 lp/mm are achieved on the (C 25 H 22 P) 2 MnCl 4 and (C 25 H 22 P) 2 MnBr 4 single crystal films, which demonstrates the great potential of large size single crystal screen for commercial high-resolution X-ray imaging applications. [ABSTRACT FROM AUTHOR]

This study provided the first in-depth investigation of the effects of large dopant incompatibility (Pr3+ and La3+ ions) on the small host lattice element (Lu3+) in Lu 3 Al 5 O 12 (LuAG) single crystal. The growth of such complex crystals from the melt presented many challenges. By engineering the ionic radius ratio of RE- and M-site cations, a single-crystal phase stabilized by configurational entropy was achieved. This investigation elucidated the crystallization behavior of configurationally disordered rare-earth aluminum garnet oxide (Lu 1−x−y Pr x La y) 3 Al 5 O 12 from the melt and characterized its functional properties, including microstructural, optical, photoluminescence, and scintillation properties, between 5 and 300 K. Relaxation of the imposed strain energy led to local perturbations and destabilization of the garnet structure. Multielemental EDS mapping, micro-Raman spectroscopy, and thermoluminescence revealed the mechanism by which atomic size mismatch drove a smooth transition from the garnet to the perovskite phase in high entropy garnets. The optical, photoluminescence, and scintillation measurements provided fundamental insights into property changes driven by incompatibility doping. Standard and modified Judd-Ofelt theory analysis of absorption spectra determined the phenomenological Judd-Ofelt parameters Ω λ and radiative lifetimes. Atomic size mismatch engineering offers a promising approach to overcoming the limitations of conventional eutectic synthesis methods. • Perovskite inclusions, driven by atomic size mismatch, extend from rim to core. • Controlled incompatible La3+,Pr3+ codoping in LuAG modify functional properties. • Scintillation light yield improved up to 30% in La3+ codoped LuAG:Pr crystals. • (La,Pr)AlO 3 perovskite forms due to size mismatch of La3+ and Pr3+ with Lu3+. • Lattice disorder affects the intensity ratio of Pr³⁺ 5d→4 f and 4 f→4 f emissions. [ABSTRACT FROM AUTHOR]

Compared to introducing Nd 70 Cu 30 (at%) alloys, the addition of Gd 70 Cu 30 exhibited a better enhancement effect, and both the best coercivity of 9.38 kOe and magnetic energy product of 29.72 MGOe were simultaneously obtained when the Gd 70 Cu 30 addition amount reached 4 wt% in the Nd-Ce-Fe-B magnet with Ce accounting for more than 14.16 wt% of the entire magnet. The further microstructural analyses showed that the higher coercivity when adding Gd 70 Cu 30 alloy was mainly attributed to the continuous thin-walled grain boundary phases and the typical core-shell structure with a Ce-rich core and Gd/Nd-rich shell. Meanwhile, the unfavorable REFe 2 -type phases had been greatly suppressed and the ratio of Ce3+ ions to Ce4+ ions had been promoted, which was generally beneficial for the improvement of magnetic properties. This work provides further insights into preparing sintered magnets with high Ce-content and high-performance. • High Ce-content magnets were prepared by intergranular addition of Gd-Cu alloys. • The microstructure was obviously optimized by introducing appropriate Gd-Cu alloys. • The mixed valence state of Ce shifted to a trivalent that favors magnetic properties. [ABSTRACT FROM AUTHOR]

This article presents a physics-informed deep learning method for the quantitative estimation of the spatial coordinates of gamma interactions within a monolithic scintillator, with a focus on Positron Emission Tomography (PET) imaging. A Density Neural Network approach is designed to estimate the 2-dimensional gamma photon interaction coordinates in a fast lead tungstate (PbWO 4) monolithic scintillator detector. We introduce a custom loss function to estimate the inherent uncertainties associated with the reconstruction process and to incorporate the physical constraints of the detector. This unique combination allows for more robust and reliable position estimations and the obtained results demonstrate the effectiveness of the proposed approach and highlights the significant benefits of the uncertainties estimation. We discuss its potential impact on improving PET imaging quality and show how the results can be used to improve the exploitation of the model, to bring benefits to the application and how to evaluate the validity of the given prediction and the associated uncertainties. Importantly, our proposed methodology extends beyond this specific use case, as it can be generalized to other applications beyond PET imaging. [ABSTRACT FROM AUTHOR]

• A new high-speed digital pulse signal acquisition and processing (SAQP) system based on micro telecommunications computing architecture (MTCA) is developed, and realizes the first application of MTCA on EAST. • The new SAQP system is capable to process and transfer data in real time. • Analyzed the characteristics of two trigger detection methods and applied them to baseline restoration, pulse processing and pile-up detection. • The real-time algorithm possesses the capability for real-time baseline restoration, n- γ discrimination, pulse amplitude analysis, pile-up event detection and dynamic pulse recording window for recording entire pulse waveform. Neutron emission spectroscopy (NES) diagnosis is an important technique in high-power thermonuclear fusion experiments for studying fast ions. In the fusion NES measurement on the Experimental Advanced Superconducting Tokamak (EAST), the liquid scintillator detector was employed. This selection was based on the detector's high sensitivity, fast time-response and superior n- γ discrimination properties. In order to meet the demands of high-parameter experiments and fully leverage the diagnostic capabilities, a new signal acquisition and processing (SAQP) system based on Micro-telecommunications computing architecture (MTCA) was developed equipped with real-time processing capabilities. The new SAQP system aims to perform real-time acquisition, processing and storage of neutron and gamma flux data from the NES system, allowing the possibility of maximum count rates of 2 Mcps during the EAST experiment. This paper presents the real-time algorithm implemented on field programmable gate array (FPGA). It possesses the capability for real-time baseline restoration, n- γ discrimination, pulse amplitude analysis, pile-up event detection and dynamic pulse recording window for recording entire pulse waveforms. The new SAQP system, including the integrated real-time algorithm, underwent detailed testing with both a signal generator and a neutron generator. The experimental results indicate that the real-time algorithm successfully achieve all expected functions, enhancing performance in n- γ discrimination and dynamically recording entire pulse waveforms at high count rates without data loss. [ABSTRACT FROM AUTHOR]