BGO Scintillators Research Articles

Analyze Methodology of ToF Spectrum on Cherenkov and Scintillation Emission in BGO Scintillator

Analyze Methodology of ToF Spectrum on Cherenkov and Scintillation Emission in BGO Scintillator

Assessing the deep learning based image quality enhancements for the BGO based GE omni legend PET/CT

BackgroundThis study investigates the integration of Artificial Intelligence (AI) in compensating the lack of time-of-flight (TOF) of the GE Omni Legend PET/CT, which utilizes BGO scintillation crystals.MethodsThe current study evaluates the image quality of the GE Omni Legend PET/CT using a NEMA IQ phantom. It investigates the impact on imaging performance of various deep learning precision levels (low, medium, high) across different data acquisition durations. Quantitative analysis was performed using metrics such as contrast recovery coefficient (CRC), background variability (BV), and contrast to noise Ratio (CNR). Additionally, patient images reconstructed with various deep learning precision levels are presented to illustrate the impact on image quality.ResultsThe deep learning approach significantly reduced background variability, particularly for the smallest region of interest. We observed improvements in background variability of 11.8%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\%$$\\end{document}, 17.2%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\%$$\\end{document}, and 14.3%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\%$$\\end{document} for low, medium, and high precision deep learning, respectively. The results also indicate a significant improvement in larger spheres when considering both background variability and contrast recovery coefficient. The high precision deep learning approach proved advantageous for short scans and exhibited potential in improving detectability of small lesions. The exemplary patient study shows that the noise was suppressed for all deep learning cases, but low precision deep learning also reduced the lesion contrast (about −30%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\%$$\\end{document}), while high precision deep learning increased the contrast (about 10%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\%$$\\end{document}).ConclusionThis study conducted a thorough evaluation of deep learning algorithms in the GE Omni Legend PET/CT scanner, demonstrating that these methods enhance image quality, with notable improvements in CRC and CNR, thereby optimizing lesion detectability and offering opportunities to reduce image acquisition time.

Long-Term Afterglow Measurement of Scintillators after Gamma Irradiation

The long-term afterglow of scintillators is an important aspect, especially when the light signal from a scintillator is evaluated in the current mode. Scintillators used for radiation detection exhibit an afterglow, which usually comes from multiple components that have different decay times. A high level of afterglow usually has a negative influence on the detection parameters for the energy resolution in spectrometry measurements or X-ray and neutron imaging. The paper deals with the long-term afterglow of some types of scintillators, which is more significant for integral measurement when the current is measured in a photodetector. The range of decay times studied was in the order of tens of seconds to days. Seven types of scintillators were examined: BGO, CaF2(Eu), CdWO4, CsI(Tl), LiI(Eu), NaI(Tl), and plastic scintillator. The scintillators were excited by gamma-ray radiation. After irradiation, the detection unit, along with the scintillator, was moved to a laboratory where the anode current of the photomultiplier tube was measured using a picoammeter for at least a day. The measurements showed that CdWO4 and plastic scintillators have relatively low long-term afterglow signals in comparison to the other scintillators studied.

Concentration Dependence Orange Light Generation Through Sm3+‐Doped Soda Lime Alumino Borate Glasses for Orange Laser Medium Material

The melt‐quenching technique is used to fabricate calcium sodium aluminum borate glasses (Sm: ANCB) doped with varying concentrations of Sm3+ ions. Characteristics of ANCBSm glasses, including density, molar volume, refractive index, absorption, emission (via visible light, X‐ray, and proton excitation), decay time, and CIE color coordinates, are analyzed. The density, molar volume, and refractive index of ANCBSm glass increased with Sm2O3 concentration. Sm3+ ions enabled photon absorption in both visible and NIR regions, with a strong reddish‐orange emission at 600 nm due to the 6H5/2 → 6P3/2 transition under various excitations. X‐ray excitation is also compared with BGO scintillation crystals. The J–O theory predicted the radiative properties of Sm3+ ion emission levels. Decay curves of the 6H5/2 levels showed a single exponential nature with a millisecond‐order lifetime. CIE chromaticity of ANCBSm glasses is in the reddish‐orange region. ANCBSm glasses have potential applications in orange laser medium material.

Development of a phoswich detector utilizing bismuth germanate crystal scintillator and polyethylene naphthalate scintillation film

In this study, we present the development of a phoswich detector system employing a Bismuth Germanate (BGO) crystal scintillator in combination with a Polyethylene naphthalate (PEN) film plastic scintillator. Phoswich detectors can contribute to various applications, including radiation monitoring, medical imaging, and nuclear physics experiments, due to their ability to discriminate between different types of radiation. The thin PEN film is sensitive to α and β radiation, while the BGO scintillator exhibits good γ radiation detection efficiency. The incident radiation type and its energy can be determined by analyzing the difference in decay times between these two scintillators. This paper presents an analysis of the detector’s response to α, β, and γ radiation, and the particle tagging efficiencies are to be over 99.9%, 92%, and 99.8%, respectively.

Study on the PET image quality according to various scintillation detectors based on the Monte Carlo simulation

Purpose: Positron emisson tomography (PET) is a crucial medical imaging scanner for the detection of cancer lesions. In order to maintain the improved image quality, it is crucial to apply detectors of superior performance. Therefore, the purpose of this study was to compare PET image quality using Monte Carlo simulation based on the detector materials of BGO, LSO, and LuAP. Materials and Methods: The Geant4 Application for Tomographic Emission (GATE) was used to design the PET detector. Scintillations with BGO, LSO and LuAP were modelled, with a size of 3.95 × 5.3 mm2 (width × height) and 25.0 mm (thickness). The PET detector consisted of 34 blocks per ring and a total of 4 rings. A line source of 1 MBq was modelled and acquired with a radius of 1 mm and length of 20 mm for 20 seconds. The acquired image was reconstructed maximum likelihood expectation maximization with 2 iteration and 10 subsets. The count comparison was carried out. Results and Discussion: The highest true, random, and scatter counts were obtained from the BGO scintillation detector compared to LSO and LuAP. Conclusion: The BGO scintillation detector material indicated excellent performance in terms of detection of gamma rays from emitted PET phantom.

Determination of boron content in Tinkal ore samples with Geant4 using MCLLS method

A new Monte Carlo-Library Least Squares (MCLLS) method was developed for the neutron inelastic-scattering and thermal-capture analysis (NITA) techniques in real-time online analysis systems to determine boron content in Tinkal ore samples. The Geant4 toolkit was used to simulate the Prompt Gamma-ray Neutron Activation Analysis (PGNAA) system for the NITA technique. Tinkal ore samples were bombarded with 14 MeV neutron beams in order to represent neutrons released from the Deuterium-Tritium (DT) neutron generator. After the simulation of shooting Tinkal ore samples with 14 MeV neutron beams was completed, histograms were obtained from Geant4. Once the histograms are broadened according to the shape calibration of the BGO scintillation detector, the spectrum (broadened histograms) are ready to be used in the MCLLS process. A single element library was created by broadened histograms of the nine Tinkal ore samples. In addition, set #10 was selected to be an unknown sample and was used for validating MCLLS. After analysing the unknown sample spectrum, boron content was estimated by the single element library created by the MCLLS method. The estimated value of the boron content by MCLLS was consistent with the laboratory result.

Response function and photon interaction of LaBr3:Ce and BGO scintillation detectors by Monte Carlo simulation

This work aims to investigate the response function and photon interaction of the LaBr3:Ce and BGO scintillation detectors using the FLUKA Monte Carlo simulation software. To improve the realism of detectors, the DETGEB card was used to activate the gaussian energy broadening (GEB) function. The GEB parameters of both detectors were obtained by fitting a nonlinear curve to the relation between FWHM and gamma-ray energy. The energy resolution (R), peak-to-Compton ratio (PCR), peak-to-total ratio (PTR), and full-energy peak efficiency (FEPE) of both detectors were investigated by simulation and experiment at different gamma-ray energy obtained from 133Ba, 137Cs, and 60Co sources. The simulated spectra of those radioisotopes were found to agree with the actual spectra. The results found that the R, PCR, and FEPE values of the LaBr3:Ce and BGO detectors tend to decrease as energy increases. Moreover, the total atomic cross-section (σt,a), effective atomic number (Zeff) and effective electron density (Neff) of both crystals was investigated by FLUKA and compared with the XCOM theoretical program covering an energy range of 15 keV to 15 MeV. The simulated results of the σt,a, Zeff, and Neff are in excellent agreement with the theoretical ones. The GEB parameters obtained from this study will improve the simulation performance of LaBr3:Ce and BGO detectors in investigating the gamma-ray response and shielding properties of materials.

Accounting for effective specularity in the DETECT2000 program when determining light collection coefficients using NaI(Tl) and BGO scintillators as an example

Accounting for effective specularity in the DETECT2000 program when determining light collection coefficients using NaI(Tl) and BGO scintillators as an example

A CNN-based four-layer DOI encoding detector using LYSO and BGO scintillators for small animal PET imaging

Objective. We propose a novel four-layer depth-of-interaction (DOI) encoding phoswich detector using lutetium–yttrium oxyothosilicate (LYSO) and bismuth germanate (BGO) scintillator crystal arrays for high sensitivity and high spatial resolution small animal PET imaging. Approach. The detector was comprised of a stack of four alternating LYSO and BGO scintillator crystal arrays coupled to an 8 × 8 multi-pixel photon counter (MPPC) array and read out by a PETsys TOFPET2 application specific integrated circuit. The four layers from the top (gamma ray entrance) to the bottom (facing the MPPC) consisted of a 24 × 24 array of 0.99 × 0.99 × 6 mm3 LYSO crystals, a 24 × 24 array of 0.99 × 0.99 × 6 mm3 BGO crystals, a 16 × 16 array of 1.53 × 1.53 × 6 mm3 LYSO crystals and a 16 × 16 array of 1.53 × 1.53 × 6 mm3 BGO crystals. Main results. Events that occurred in the LYSO and BGO layers were first separated by measuring the pulse energy (integrated charge) and duration (time over threshold (ToT)) from the scintillation pulses. Convolutional neural networks (CNNs) were then used to distinguish between the top and lower LYSO layers and between the upper and bottom BGO layers. Measurements with the prototype detector showed that our proposed method successfully identified events from all four layers. The CNN models achieved a classification accuracy of 91% for distinguishing the two LYSO layers and 81% for distinguishing the two BGO layers. The measured average energy resolution was 13.1% ± 1.7% for the top LYSO layer, 34.0% ± 6.3% for the upper BGO layer, 12.3% ± 1.3% for the lower LYSO layer, and 33.9% ± 6.9% for the bottom BGO layer. The timing resolution between each individual layer (from the top to the bottom) and a single crystal reference detector was 350 ps, 2.8 ns, 328 ps, and 2.1 ns respectively. Significance. In conclusion, the proposed four-layer DOI encoding detector achieved high performance and is an attractive choice for next-generation high sensitivity and high spatial resolution small animal positron emission tomography systems.

An efficient digital pulse processing approach for identification of BGO and LSO scintillator crystals

Identification and discrimination between BGO and LSO scintillators is a fundamental target for handling parallax error within positron emission tomography (PET) applications by depth of interaction. An approach is built for discrimination and identification of BGO and LSO scintillator crystals. This approach is tested using a simulated BGO and LSO pulses. A Matlab Simulink model is implemented for simulation and creation of BGO and LSO scintillation pulses. The simulated pulses depend on 22Na radiation source. The suggested approach has two different algorithms. The first algorithm uses both 1D-Walsh ordered fast Walsh-Hadamard transform (1WFWHT) and fast Chebyshev transform (FCHT) for extracting the features of crystal pulses. The optimum features are selected from 1WFWHT and FCHT using one of three optimization techniques that are binary dragonfly optimization (BDA), binary atom search optimization (BASO) and binary Harris Hawk optimization (BHHO). These optimized features are trained and tested using one of three based classifiers. These classifiers are Naive Bayes classifier (NBC), hierarchical prototype-based (HP) classifier and adaptive neuro-fuzzy inference system (ANFIS) classification. The ANFIS classifier achieves the best accuracy with all optimum (BASO, BDF and BHH) FCHT features. However, the NB classifier introduces the highest accuracy with all optimum (BASO, BDF and BHH) FWHT 1D features. The second algorithm uses the conventional neural network (CNN) for extracting the pulse features. Then, the deep neural network (DNN) is applied for training and testing of the captured pulses. The suggested algorithms are verified and compared in respect of statistical measures. The compared results confirm that the best accuracy and identification rate is accomplished using DNN algorithm. Besides, the DNN has better results compared to conventional classification techniques with optimum feature selection techniques in respect of time consumption. The proposed approach aids in the realisation of overcoming parallax inaccuracy in PET.

BINGO: Background reduction techniques for 0ν2β bolometric experiments

BINGO is a project dedicated to explore new methods for background reduction in experiments searching for 0ν2β decay. It is based on bolometers, one of the most promising techniques to search for 0ν2β. CUORE and CUPID-Mo/0 are the main bolometric experiments that have illustrated the most relevant limiting factors on sensitivity the bolometers are facing. Surface αs are the main source of background in CUORE, and this contribution has been mitigated in CUPID-Mo/0 using dual heat-light channels, i.e., a main absorber embedding the 2β decay isotope facing a light detector. In this case, surface α rejection is achieved thanks to the lower α light output compared to β/γ. However, there are still other background components that limit the sensitivity of the experiments, such as pile-ups due to random coincidences of physical events, external γ background and β surface radioactivity. BINGO’s proposed technology aims at reducing the background index down to 10−5 counts/(keV kg yr) in the region of interest, thus boosting the sensitivity on the effective Majorana neutrino mass. This can be achieved by: (i) having a revolutionary detector assembly with a reduction in the passive materials facing the detector; (ii) increasing the light detector sensitivity thanks to Neganov-Luke amplification; (iii) using an active shield, based on BGO scintillators with bolometric light detector readout to surround the experimental volume. The main text describes the listed approaches in detail, as well as the recent results of prototype tests.

Effect of Gd2O3 concentration on photo and X-rays excited luminescence characteristics of Dy3+-Activated Li2O3–SrO–B2O3 glass

Gd3+ and Dy3+-doped borate glasses are considered attractive candidates for white light emission. In this work, the samples, developed by the melt-quenching route, contain a mixture of Gd3+ and Dy3+ with known molar compositions. The determined physical parameters indicate structural changes. Information regarding the Judd-Ofelt (JO) intensity parameters and spectral radiative features, calculated from absorption spectra and emission properties, respectively, are obtained. Excitation and photoluminescence characteristics of the developed samples are found. The energy transfer (ET) efficiency from Gd3+ → Dy3+ is determined by considering their emission intensities and lifetime. The quantum efficiency (QE) of glasses is evaluated. Inokuti –Hirayama (IH) model shows that the Dy3+ → luminescence center ET is dominated by dipole-dipole coulomb interaction. Due to the excitation of more secondary electrons, the X-ray luminescence shows an intense emission pattern. Furthermore, we find the integral scintillation efficiency to be 8.4% of the commercial BGO scintillator crystal for the 10 mol% Gd2O3-doped glass. Commission International deI’Eclairage (CIE) color coordinates and color correlated temperature (CCT) show the suitability of tested samples for white-light applications.

Enhanced photoluminescence and radioluminescence of Dy3+-doped Ba–Na–B glasses

This research aims to study the photoluminescence and radioluminescence enhancement for Dy3+-doped Ba–Na–B glasses by (1) adding fluoride contain to the host glass and (2) adding Gd3+ to the glass compositions. The absorption spectra show 7 absorption bands in UV-Vis-NIR regions, assigned by 6H15/2 → 6P7/2 (347 nm), 4I15/2 (452 nm), 6F5/2 (796 nm), 6F7/2 (898 nm), 6F9/2 (1089 nm), 6H9/2 (1265 nm) and 6H11/2 (1674 nm). The excitation spectra show the most intense excitation wavelength at 350 nm. The emission spectra, excited with 350 nm, show the two major emission bands at 482 nm (4F9/2 → 6H15/2) and 575 nm (4F9/2 → 6H13/2). The emitted light is located in the white region, according to CIE 1931 chromaticity diagram. For fluoride adding study, 10BaO:25Na2O:64B2O3:1Dy2O3 (DyO) and 10BaO:25NaF:64B2O3:1Dy2O3 (DyF) were fabricated. The emission intensity of the DyF glass is higher than the DyO glass. For Gd3+ adding study, the 10BaO:25Na2O:(64-x)B2O3:1Dy2O3:xGd2O3 (x = 0, 2.5, 5, 7.5 and 10 mol%) were fabricated. For the photoluminescence, the glass sample with 5 mol% of Gd3+ ions provided the highest emission light yield. For the radioluminescence, the glass sample with 2.5 mol% of Gd3+ ions provided the highest scintillation potential at 14.15% compared with the BGO scintillation crystal.

Estimating the influence of various factors on the uncertainty of light collection simulation in scintillators

The paper is dedicated to the evaluation of statistical uncertainty of simulating the process of light transfer in NaI (Tl) and BGO scintillators by Monte Carlo method. The DETECT2000 program with a unified surface model was used. The process of light transfer (“fate”) by light photons was traced from the moment of appearance in the scintillator to the moment of passing through its exit window. The light collection coefficient was determined as the ratio of the number of photons that passed through the exit window to a given number of emitted photons. Different values of the number of emitted photons, optical transparency coefficients and fractions of the surface diffuse reflection were set. Multiple repetitions of the simulation process for a different set of properties made it possible to evaluate the precision and type A uncertainty of simulating the light collection coefficient for all possible options. It is shown that the uncertainty decreases when the statistics of the emitted photons is increased, and increases when the transparency and diffuse reflection fraction are decreased.

LONG-TERM AFTERGLOW OF SOLID SCINTILLATORS.

Most of scintillators used for radiation detection exhibit afterglow, which is emission of light with longer decay times than that of main light pulse. High signal from afterglow has usually negative influence on detection parameters, e.g. for energy resolution in spectrometry measurements. The paper deals with long-term afterglow of some types of scintillators, which is more significant in the case of integral measurement when current in the photodetector is measured. The range of studied decay times was in the order of tens of seconds to days. Seven types of scintillators were measured: BGO, CaF2(Eu), CdWO4, CsI(Tl), LiI(Eu), NaI(Tl) and plastic scintillator. Excitation of scintillators was made using a UV lamp. After UV irradiation, a scintillator was inserted to scintillation detection unit and the anode current of photomultiplier tube was measured with a picoammeter. As results, CaF2(Eu) and plastic scintillator have relatively low long-term afterglow signal compared with other measured scintillators.

Optical, luminescence, and energy transfer studies of Gd3+/Dy3+ doped potassium gadolinium borophosphate glasses

The K2O–Gd2O3–B2O3–P2O5 glass doped with Dy2O3 (Dy:KGPB) were synthesized by the melt-quenching technique. These glasses were subjected to characterize the physical, structure, optical and luminescence properties. It was observed that the density, molar volume and refractive index of glass increased with increasing Dy2O3 concentration. The FTIR result confirmed the main glass network of BOB and POP linkages those were degraded by adding Dy2O3 modifier. Glasses absorbed photons in ultraviolet, visible light and near-infrared region. The photoluminescence under direct Dy3+ excitation performed the strong emissions at 574 and 482 nm corresponding to 4F9/2 → 6H13/2 and 4F9/2 → 6H15/2 transition, respectively. The Gd3+ excitation also caused strong emission of Dy3+ by the Gd3+-Dy3+energy transfer. Glass doped with 1.00 mol% of Dy2O3 owned the highest emission intensity due to the concentration quenching. The lifetime of 4F9/2 level was found to decrease with addition of Dy2O3 content via dipole-diploe interaction between Dy3+ ion. Judd-Ofelt (J-O) intensity parameters were initially calculated and applied to evaluate the radiative parameters such as branching ratios, radiative transition probabilities, and stimulated emission cross-sections. The radioluminescence of glass was also investigated and found the scintillation efficiency around 15.6%, compared to BGO scintillator. The Dy:KGPB glass has an interesting potential for solid-state laser, LED and X-ray detection applications.

CALET Search for Electromagnetic Counterparts of Gravitational Waves during the LIGO/Virgo O3 Run

The CALorimetric Electron Telescope (CALET) on the International Space Station consists of a high-energy cosmic-ray CALorimeter (CAL) and a lower-energy CALET Gamma-ray Burst Monitor (CGBM). CAL is sensitive to electrons up to 20 TeV, cosmic-ray nuclei from Z = 1 through Z ∼ 40, and gamma rays over the range 1 GeV–10 TeV. CGBM observes gamma rays from 7 keV to 20 MeV. The combined CAL-CGBM instrument has conducted a search for gamma-ray bursts (GRBs) since 2015 October. We report here on the results of a search for X-ray/gamma-ray counterparts to gravitational-wave events reported during the LIGO/Virgo observing run O3. No events have been detected that pass all acceptance criteria. We describe the components, performance, and triggering algorithms of the CGBM—the two Hard X-ray Monitors consisting of LaBr3(Ce) scintillators sensitive to 7 keV–1 MeV gamma rays and a Soft Gamma-ray Monitor BGO scintillator sensitive to 40 keV–20 MeV—and the high-energy CAL consisting of a charge detection module, imaging calorimeter, and the fully active total absorption calorimeter. The analysis procedure is described and upper limits to the time-averaged fluxes are presented.

Advances in heterostructured scintillators: toward a new generation of detectors for TOF-PET

Objective. Time-of-flight-positron emission tomography would highly benefit from a coincidence time resolution (CTR) below 100 ps: improvement in image quality and patient workflow, and reduction of delivered dose are among them. This achievement proved to be quite challenging, and many approaches have been proposed and are being investigated for this scope. One of the most recent consists in combining different materials with complementary properties (e.g. high stopping power for 511 keV -ray and fast timing) in a so-called heterostructure, metascintillator or metapixel. By exploiting a mechanism of energy sharing between the two materials, it is possible to obtain a fraction of fast events which significantly improves the overall time resolution of the system. Approach. In this work, we present the progress on this innovative technology. After a simulation study using the Geant4 toolkit, aimed at understanding the optimal configuration in terms of energy sharing, we assembled four heterostructures with alternating plates of BGO and EJ232 plastic scintillator. We fabricated heterostructures of two different sizes (3 × 3 × 3 mm3 and 3 × 3 × 15 mm3), each made up of plates with two different thicknesses of plastic plates. We compared the timing of these pixels with a standard bulk BGO crystal and a structure made of only BGO plates (layered BGO). Main results. CTR values of 239 ± 12 ps and 197 ± 10 ps FWHM were obtained for the 15 mm long heterostructures with 100 µm and 200 µm thick EJ232 plates (both with 100 µm thick BGO plates), compared to 271 ± 14 ps and 303 ± 15 ps CTR for bulk and layered BGO, respectively. Significance. Significant improvements in timing compared to standard bulk BGO were obtained for all the configurations tested. Moreover, for the long pixels, depth of interaction (DOI) collimated measurements were also performed, allowing to validate a simple model describing light transport inside the heterostructure.

Scintillator surface modification by glancing angle deposition of thin ZrO2 films

In this research, we evaluated the properties of ZrO2 films produced with the glancing angle deposition technique and evaluated its effect on the detector properties. With using ZrO2, we created films with a refraction index in the range of 1.3 to 2.0, and produced a four layer graded-index (GRIN) antireflection coating. A BGO scintillator sample with an applied GRIN coating demonstrated up to ∼ 53% light output enhancement in comparison with the reference ones. For LYSO scintillators, the observed magnitude of the effect was less, ∼ 11%. Thus, this method is a technologically applicable way to improve the characteristics of existing and projected detector systems.