Glass Scintillator Research Articles

Tb-doped borosilicate glass scintillators with high thermal stability for high-resolution X-ray imaging

Scintillators with high thermal stability and excellent spatial resolution are desirable for X-ray imaging applications in harsh environments. Here, Tb3+-doped borosilicate glass scintillators were prepared using conventional melt-quenching method. The optimized Tb3+-doped borosilicate glass (G-15Tb) scintillator exhibited a significantly higher X-ray excited luminescence intensity (147 % of Bi4Ge3O12). Furthermore, it possessed a remarkable imaging spatial resolution of 20 lp/mm, surpassing the standard requirement for X-ray imaging and medical computed tomography scans (2 lp/mm). Moreover, the X-ray excited luminescence intensity of G-15Tb glass sample remained unchanged even after being submerged in water for 30 days, indicating exceptional water resistance. Additionally, the integral intensity of photoluminescence at 573 K is 96.7 % of its initial value. Most importantly, the G-15Tb glass scintillator remains high-quality X-ray images even at elevated operating temperatures. Therefore, the Tb3+-doped borosilicate glass scintillator holds immense potential for high-resolution X-ray imaging in harsh environments.

Demonstration of shape analysis of neutron resonance transmission spectrum measured with a laser-driven neutron source

Laser-driven neutron sources (LDNSs) can generate strong short-pulse neutron beams, which are valuable for scientific studies and engineering applications. Neutron resonance transmission analysis (NRTA) is a nondestructive technique used for determining the areal density of each nuclide in a material sample using pulsed thermal and epithermal neutrons. Herein, we report the first successful NRTA performed using an LDNS driven by the Laser for Fast Ignition Experiment at the Institute of Laser Engineering, Osaka University. The key challenge was achieving a well-resolved resonance transmission spectrum for material analysis using an LDNS with a limited number of laser shots in the presence of strong background noise. We addressed this by employing a time-gated 6Li\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{6}{\ extrm{Li}}$$\\end{document}-glass scintillation neutron detector to measure the transmission spectra, reducing the impact of electromagnetic noise and neutron and gamma-ray flashes. Output waveforms were recorded for each laser shot and analyzed offline using a counting method. This approach yielded a spectrum with distinct resonances, which were attributed to 115In\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{115}\\,{\ extrm{In}}$$\\end{document} and 109Ag\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{109}{\ extrm{Ag}}$$\\end{document}, as confirmed through neutron transmission simulation. The spectrum was analyzed using the least-square nuclear-resonance fitting program, REFIT, demonstrating the possibility of using an LDNS for nondestructive areal-density material characterization.

High transparency Ce3+-doped oxyfluoride glass scintillator for X-ray imaging and γ-ray detection

High transparency Ce3+-doped dense gadolinium aluminum borosilicate (GSx) glass scintillator was synthesized in reducing atmosphere by melt-quenching process. The transmittance of the glasses exceeds 80%, and the light attenuation length is between 5-20 cm within the range of 400–600 nm. GSx glass shows an photoluminescence (PL) in range of 350–550 nm, with the strongest emission peak around 420 nm. The PL decay time of GSx glasses is around 37 ns, with a maximum PL quantum yield of 44.05%. The integrated X-ray excited luminescence (XEL) intensity of GSS glass is 52.5% compared with BGO crystal. For X-ray imaging, GSL glass based imaging system shows a high spatial resolution of 9 lp/mm, which is comparable to CsI:Tl X-ray detectors. Under γ-ray, the highest light yield of GSS glass is 1235 ph/MeV with an energy resolution of 24.0% at 662 keV, close to that of BSO crystal. The scintillation decay time of GSx glasses is consisted of fast (∼100 ns) and slow (∼560 ns) components. In thermally stimulated luminescence (TSL), GSS glass exhibits a strong TSL peak at approximately 440 K, with low intensity shoulders at about 520 K, implying different types of defects and traps. Therefore, GSx glass has promising prospects for X-ray imaging and high-energy physics applications.

Optimizing the spatial resolution and gamma discrimination of SiPM-based Anger cameras

SiPM Anger cameras have been designed for use as 2-dimensional thermal neutron detectors for scientific applications such as at single crystal diffraction instruments. These cameras utilize a neutron sensitive scintillator and an array of SiPM photosensors, separated by a light spreading glass. While this optics package is very effective at detecting and positioning neutrons, it is also sensitive to gamma rays, which are a source of unwanted noise. In this work, we underwent a search of scintillator and spreader glass thicknesses to determine the optimal combination for maximizing spatial resolution. Both experimental results and GEANT4 simulations are presented. To address the issue of gamma ray detection, we have also designed and presented a multi-layer scintillator that reduces the amount of scintillation light produced via gamma-ray energy deposition, allowing for easier pulse-height discrimination. A sample of this geometry has been produced that results in a factor of 2 improvement over an equivalent thickness monolithic scintillator.

Flexible and Transparent Phosphonium-Based Metal Halide Glass Scintillators for High-Resolution X-ray Imaging

Flexible and Transparent Phosphonium-Based Metal Halide Glass Scintillators for High-Resolution X-ray Imaging

Neutron spectroscopy of plutonium using a handheld detection system

The ability to distinguish multiple forms of plutonium from one another, such as oxide and metal, is paramount in areas of nuclear nonproliferation and international safeguards. In its metal form, plutonium can be readily used in a nuclear weapon, while oxide forms are associated with nuclear reactor fuel. Oxide-based plutonium forms emit neutrons with an energy spectrum that is significantly different from the fission neutrons that are emitted from plutonium metal. Organic scintillation detectors output pulses that are proportional to the neutron energy deposited, and therefore present a means of distinguishing these plutonium forms based on their energy spectra. In this work, metal and oxide forms of plutonium were measured using a handheld detection system based on an organic glass scintillator. Monte Carlo modeling of these experiments was performed to provide insight into the origin of the features in the observed light output spectra. Through analysis of multiple regions of these spectra, in a matter of minutes we were able to unambiguously discriminate oxide and metal plutonium forms from one another and from a plutonium-beryllium neutron source, which was considered for comparison because these sources are commonly used in industrial applications. The ability to discriminate weapons-usable material from nuclear reactor fuel has applications in nuclear treaty verification and safeguards.

Tb3+ doped silicoborate glass scintillator for high resolution synchrotron X-rays imaging application

This research aims to develop a combination of SiO2 and B2O3 glass former (called, silicoborate glass) to be used as a scintillation material for digital radiography application. The silicoborate glass doped with different concentration of Tb2O3, xTb2O3–7.5Gd2O3–40Na2O–5SiO2– (47.5-x)B2O3, where x = 0, 1, 2, and 3 mol% (xTb:7.5Gd) were prepared by melting and then rapid quenching in graphite mold. The density of the prepared glasses was high with Tb2O3 concentration, indicating that the glass became denser and could strongly interact with X-rays. The molar volume increased with Tb2O3 concentration, suggesting the increase of Non-Bridging Oxygen (NBOs) in glass matrix. The xTb:7.5Gd glasses absorbed photons in visible and near-infrared regions and was observed that the absorption bands increased with Tb2O3 concentration, which was the result of the 4f6-4f6 transitions behavior of Tb3+ ions. The photoluminescence and radioluminescence results revealed the distinct emission occurring at 544 nm (5D4→7F5). The photoluminescence quantum yield (PLQY) of glass had the maximum efficiency at 30.85%. The luminescence peak area under X-rays excitation glass was maximum at 109% of BGO crystal. CIE 1931 chromaticity of the xTb:7.5Gd glasses showed the color coordinates in yellowish-green area. The decay time of the xTb:7.5Gd glasses were in the millisecond range for different excitations. The probability of energy transfer was investigated between Gd3+ and Tb3+ ions in glass and may occur mainly between the 6P7/2 level of Gd3+ and 5H7 level of Tb3+. The X-rays imaging using the developed glass as a scintillator was performed by Synchrotron X-rays and the spatial resolution 6 lp/mm was achieved. These results demonstrate that the 3 mol% of Tb2O3 doped silicoborate glass can be used as a scintillator and can be applied for a high-resolution Synchrotron X-rays imaging system.

Energy transfer study on dense and transparent Eu3+/Tb3+-coactivated TeO2-Gd2O3-WO3-ZnO glass scintillators☆

Tb3+-, Eu3+-activated and Eu3+/Tb3+-coactivated TeO2-Gd2O3-WO3-ZnO (TGWZ) glasses with the density of about 6.60 g/cm3 were successfully synthesized by a melt-quenching method. These glass scintillators show a line transmittance coefficient in excess of 80% in the strongest green-emitting regions of Tb3+ ions. The optimal concentration of incorporated Tb3+ and Eu3+ ions and the corresponding interaction mechanism are determined in both Tb3+ and Eu3+-activated TGWZ glasses. Compared with that of Tb3+-activated TGWZ glasses, the luminous intensity of the Eu3+/Tb3+-coactivated TGWZ glasses is enhanced by 7.6 times, which can be attributed to the effective energy transfer (ET) from Tb3+ to Eu3+ ions. By investigating the concentration-dependent optical properties of these glasses including transmittance, photoluminescence (excitation and emission spectra), photoluminescence decay, the mechanism of ET in Eu3+/Tb3+-coactivated TGWZ glass scintillators is obtained. Also, the potential scintillation properties of the TGWZ glass scintillators are discussed by X-excited luminescence (XEL) spectra and the corresponding X-ray dose response tailored by various current intensity within 0–240 μA (which corresponding to 0–40000 mGy).

Preliminary optimization study on the PFA-based GSHCAL for the CEPC

Precision measurements of properties of the Higgs, W and Z bosons are the key scientific goals at future e + e - Higgs factories. A main challenge for these goals is to fulfill an unprecedented jet energy resolution, and the design of the hadronic calorimeter (HCAL) is found to be one of the most important factors. The conceptual design of high-granularity glass scintillator hadronic calorimeter (GSHCAL) has been proposed recently, which can achieve a Boson Mass Resolution (BMR) of around 3.38% with an initial parameter configuration and show great potential to significantly increase the sensitivities to the most physics measurements at future e^+e^- colliders. Nevertheless, more studies on the design optimization of the GSHCAL are necessary to balance the key physics performance (i.e. the BMR) and the cost, as well as the engineering complexity. In this paper, the optimizations for several key parameters of the GSHCAL are discussed and different GSHCAL configurations are compared, which provide an important reference for the GSHCAL design. Besides, the R&D progress of high-performance and large-area glass scintillators is also introduced.

Luminescence properties of Tb3+ -doped sodium phosphate glasses for green laser and X-ray imaging application

Tb3+ doped sodium-gadolinium-aluminum-phosphate glass samples (PGNA) with chemical compositions 30Na2CO3:8Gd2O3:5Al2O3:(57- x)P2O5: x Tb4O7 (where x=0, 0.25, 0.5, 1.0, 2.0, 3.0, 4.0, and 5 mol. %) were manufactured by using adopting the conventional melt quenching technique. The PXRD study of the prepared samples was used to confirm the amorphous structure. FE-SEM, EDS, and FTIR studies were carried out to analyze the elemental and structural characteristics of synthesized glasses. The X-ray induced luminescence spectra were obtained at room temperature and the emission peak at 311 nm corresponding to Gd3+ transition was observed decreasing with the increase of Tb4O7 concentrations, while emission peak intensities corresponding to Tb3+ electronic transitions increased with the concentrations of Tb4O7. The results from the photoluminescence (PL) studies in the UV–Vis–NIR region showed the glasses emitting intense green light with the highest peak at 544 nm under excitations at 220, 272, and 311 nm. The PL emission intensities were found reasonably high under characteristic excitations of both Gd3+ and Tb3+, peaking at 380, 414, 437, 489, 544, 584, and 623 nm, which corresponding to 5D3→7F6,5D3→7F5, 5D3→7F4, 5D4→7F6, 5D4→7F5, 5D4→7F5, 5D4→7F4, 5D4→7F3 transitions, respectively. The decay time of Tb3+ ions has been observed to decrease when the concentration of Tb4O7 increases. The energy transfer from Gd3+ to Tb3+ was found increased with increasing of Tb3+ concentrations. The CIE 1931 chromaticity coordinates of Tb doped PGNA glasses were found to be in the green range, indicating a strong potential for green laser application. The results from X-ray imaging showed that Tb-doped glass scintillators promise of efficient and low-cost solution for X-ray imaging applications.

Novel Tb3+ doped borophosphate glass scintillator for X-ray imaging

In this study, we introduce an efficient green-emitting material made from Tb3+ doped borophosphate scintillating glass for X-ray imaging. An influence of Tb2O3 concentration on the physical, optical, luminescent, and scintillation properties of glasses were investigated. The glass density and refractive index increase, while the molar volume and Tb3+ inter-ionic distance decreases with Tb2O3 addition. These glasses absorb the photons in range of UV, Vis, and NIR. The excitations by UV and X-ray on glasses causes the strong green emission centered around 545 nm by the 5D4 → 7F5 transition of Tb3+. The energy transfer from Gd3+ to Tb3+ was occurred in this emission. The glass doped with 4 mol% of Tb2O3 demonstrates the highest emission intensity at 545 nm due to the concentration quenching. The decay time of glasses are in few milliseconds. The integral X-ray scintillation efficiency of 4 mol% doped glass is 52% compared to that of BGO crystal. Additionally, this glass was proceeded in the X-ray imaging and yielded the image with satisfied resolution, characteristics and MTF values, compared to that obtained from YAG:Ce crystal. The developed glass has a potential for X-ray imaging applications, especially in the medical imaging, flaw detection, and security inspection.

Measurement of the response of a [formula omitted]Li-glass detector to gamma rays by a coincidence method

The response of a gamma-ray spectrometer is generally determined by analyzing full-energy peaks. However, full-energy peaks cannot be measured easily in the case of scintillation detectors that consist of light elements, such as glass scintillators. Only a strong Compton plateau appears in the spectrum of such detectors. Therefore, Compton edgers were used to evaluate the response of these detectors. The response of a low-resolution 6Li-glass detector to gamma rays was measured for the first time by a coincidence method with a high-resolution LaBr3:Ce detector using cascade gamma rays (2.75 and 1.37 MeV) from a 24Na source. Coincidence gates were applied at the peaks of the spectrum of the LaBr3:Ce detector at the 0.51 MeV annihilation peak, and the sum peaks of a gamma ray and a backscattered gamma ray. By analyzing the gated spectra of the 6Li-glass detector, the energy-dependent detector response (i.e., the output strength and its dispersion) was determined.

Muon beamtest results of high-density glass scintillator tiles

To achieve the physics goal of precisely measure the Higgs, Z, W bosons and the top quark, future electron-positron colliders require that their detector system has excellent jet energy resolution. One feasible technical option is the high granular calorimetery based on the particle flow algorithm (PFA). A new high-granularity hadronic calorimeter with glass scintillator tiles (GSHCAL) has been proposed, which focus on the significant improvement of hadronic energy resolution with a notable increase of the energy sampling fraction by using high-density glass scintillator tiles. The minimum ionizing particle (MIP) response of a glass scintillator tile is crucial to the hadronic calorimeter, so a dedicated beamtest setup was developed for testing the first batch of large-size glass scintillators. The maximum MIP response of the first batch of glass scintillator tiles can reach up to 107 p.e./MIP, which essentially meets the design requirements of the CEPC GSHCAL. An optical simulation model of a single glass scintillator tile has been established, and the simulation results are consistent with the beamtest results.

Eu2+ doped cesium alkaline earth chloride nanocrystals in glass for X-ray imaging

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+: CsCaCl3, Eu2+: CsSrCl3, and Eu2+: Cs2BaCl4 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+: CsCaCl3 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.

Performance optimization for a scintillating glass electromagnetic calorimeter at the EIC

The successful realization of the EIC scientific program requires the design and construction of high-performance particle detectors. Recent developments in the field of scientific computing and increased availability of high performance computing resources have made it possible to perform optimization of multi-parameter designs, even when the latter require longer computational times (for example simulations of particle interactions with matter). Procedures involving machine-assisted techniques used to inform the design decision have seen a considerable growth in popularity among the EIC detector community. Having already been realized for tracking and RICH PID detectors, it has a potential application in calorimetry designs. A SciGlass barrel calorimeter originally designed for EIC Detector-1 has a semi-projective geometry that allows for non-trivial performance gains, but also poses special challenges in the way of effective exploration of the design space while satisfying the available space and the cell dimension constraints together with the full detector acceptance requirement. This talk will cover specific approaches taken to perform this detector design optimization.

Transparent Glass Composite Scintillator with High Crystallinity for Efficient Thermal Neutron Detection

AbstractThe sensitive and rapid detection of thermal neutrons holds significant importance in various fields such as energy utilization, medical treatment, and national defense. However, the available thermal neutron scintillator is difficult to reach this target, mainly limited by the optical and scintillating performance. Herein, the in situ crystallization strategy of glass to construct scintillation glass composites for efficient thermal neutron detection is proposed. The congruent crystallization of the hybridized alkali earth silicate glass system may not only achieve high crystallinity, but also will keep the refractive indexing matching between the precipitated crystal and precursor glass phases. The prepared glass composites feature high luminescence efficiency, optical transmission and excellent neutron response properties. These factors collectively contribute to the robust neutron scintillation performance with a light output of ≈36 000 photons/neutron, which represents the highest value among glass‐based scintillators. Moreover, the composite configuration brings about the additional function of thermal neutron and γ‐ray discrimination. By using this composite scintillator, the neutron detector is constructed and demonstrates its application for detecting thermal neutron and distinguishing it from γ‐ray in an online way. The studies prove that glass composites with high crystallinity are expected to be promising candidates for a new generation of multifunctional neutron detectors.

High-Density Glass Scintillators for Proton Radiography-Relative Luminosity, Proton Response, and Spatial Resolution.

Proton radiography is a promising development in proton therapy, and researchers are currently exploring optimal detector materials to construct proton radiography detector arrays. High-density glass scintillators may improve integrating-mode proton radiography detectors by increasing spatial resolution and decreasing detector thickness. We evaluated several new scintillators, activated with europium or terbium, with proton response measurements and Monte Carlo simulations, characterizing relative luminosity, ionization quenching, and proton radiograph spatial resolution. We applied a correction based on Birks's analytical model for ionization quenching. The data demonstrate increased relative luminosity with increased activation element concentration, and higher relative luminosity for samples activated with europium. An increased glass density enables more compact detector geometries and higher spatial resolution. These findings suggest that a tungsten and gadolinium oxide-based glass activated with 4% europium is an ideal scintillator for testing in a full-size proton radiography detector.

Gamma-ray imaging of Np-237 metal using an organic glass imager

Neutron and gamma-ray imaging systems are deployed within the field of nuclear safeguards for the detection and localization of special nuclear materials and other materials of interest. 237Np is one of these materials of interest due its presence in spent nuclear fuel and potential for use in nuclear weapons when purified. Here, for the first time, a 6 kg neptunium sphere (98.8 wt% 237Np) was measured using a dual-particle imager, from the University of Michigan, consisting of organic glass and inorganic scintillators. The novel composition of organic glass scintillator was recently developed at Sandia National Labs and has been used in particle imaging systems due to its time resolution and particle discrimination capabilities. Gamma-ray energy spectra from single and coincident events were extracted and the sequencing of Compton scatter and photoelectric absorption gamma-ray events was used to generate images using simple backprojection. The emissions of interest in this work are the 312 keV and 416 keV gamma rays from 233Pa, a daughter isotope from the neptunium decay series. The results of this work show that there is close agreement between the true source location in angular space and the converged location from the gamma ray images created using the system. The gamma spectroscopy from single and coincident events also identified the characteristic emission from the daughter isotope and could be used to assist with the identification of 237Np. Furthermore, successful localization of the source with 5 s of data demonstrates the practical application of the imaging system for imaging and detection of material in weapons-useable quantities.

An evaluation method for nuclear radiation detection performance of glass scintillator

An evaluation method for nuclear radiation detection performance of glass scintillator

Field tests for performance evaluation of a new spent-fuel verification system in heavy water reactor

The optical fiber-based measurement system has been utilized for inspecting CANDU-type spent fuel at the Wolsung site in South Korea under the nuclear safeguards of the International Atomic Energy Agency (IAEA). In our previous studies, we developed a new spent-fuel verification system to address issues of the existing instrument. While our prior work primarily focused on equipment development, we had not yet conducted comprehensive field tests to assess its performance. Recently, we conducted field tests at the Wolsung Unit 4 to thoroughly evaluate the newly developed spent-fuel verification system's performance. This paper discusses the results of these field tests, with a focus on signal sensitivity, the system's capability to distinguish neighboring spent-fuel bundles, and the optical fiber background signals. Additionally, we conducted experiments to assess how different scintillation materials impact the system's performance, including p-terphenyl organic scintillator, PVT plastic scintillator, and lithium glass scintillator. The experimental results demonstrated that the new instrument equipped with the p-terphenyl organic scintillator outperformed the existing system. The p-terphenyl scintillator emerged as the superior choice among the three radiation scintillators. Signals that were previously undetectable using the Li glass scintillator were observed in the signals obtained with the p-terphenyl and PVT plastic scintillators. The remarkable performance of the new verification instrument is attributed mainly to the p-terphenyl's high light output and low decay time. The newly developed verification system is expected to streamline IAEA safeguards inspection efforts, reducing both time and the burden on nuclear operators. This report represents the first successful application of the p-terphenyl scintillator as a radiation detector in a wet spent fuel pool. The experimental findings presented in this paper are anticipated to be valuable for researchers working on radiation detectors suitable for high radiation environments in water.