7,338 results on '"SCINTILLATORS"'
Search Results
252. Time Resolution and Light Yield of Scintillation Detector Samples for the Time-of-Flight Neutron Detector of the BM@N Experiment.
- Author
-
Guber, F. F., Ivashkin, A. P., Karpushkin, N. M., Makhnev, A. I., Morozov, S. V., and Serebryakov, D. V.
- Subjects
- *
SCINTILLATION counters , *NEUTRON counters , *SCINTILLATORS , *NUCLEAR research , *FAST neutrons , *NEUTRON measurement , *NEUTRON temperature , *NEUTRINO detectors , *PHOTONS - Abstract
A new compact time-of-flight neutron detector is being planned for the identification and energy measurement of neutrons produced in nucleus-nucleus interactions at energies up to 4 AGeV at the BM@N experiment, located at the Nuclotron (Joint Institute for Nuclear Research, Dubna, Russia). This detector will be used to measure neutron yields and azimuthal flows, which should be sensitive to the equation of state of dense nuclear matter, as shown in various theoretical models It is proposed to use plastic scintillators produced at JINR and IFTP and silicon photomultipliers with a sensitive area of 6 × 6 mm2 for photon registration, one for each scintillation cell. To achieve the required neutron energy resolution (of the order of several percent) in the energy range up to 4 GeV, the time resolution of scintillation detectors should be 100−150 ps. The concept of a time-of-flight neutron detector is discussed. The results of measurements of the light yield and time resolution of several scintillation detector specimens of various sizes and two types of silicon photomultipliers are presented. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
253. Dependences of Magnetic Properties on the Grain Size and Hard/Soft Magnetic Phase Volume Ratio for Ce 2 Fe 14 B/α-Fe and Nd 2 Fe 14 B/α-Fe Nanocomposites.
- Author
-
Liu, Xiangyi, Zhou, Bang, Yuan, Bin, and Liu, Zhongwu
- Subjects
- *
MAGNETIC properties , *GRAIN size , *NANOCOMPOSITE materials , *DEMAGNETIZATION , *REMANENCE , *SCINTILLATORS , *DUAL-phase steel - Abstract
The magnetic properties of magnetic nanocomposites consisting of hard and soft magnetic phases are dependent not only on the intrinsic properties but also on the grain structure and volume ratio of the two phases. In this study, we performed a systematic micromagnetic simulation on the magnetic properties of Ce2Fe14B/α-Fe and Nd2Fe14B/α-Fe nanocomposites. The volume fractions of the hard magnetic Nd2Fe14B or Ce2Fe14B phase were varied from 80% to 40%, and the grain sizes of the hard magnetic phase and the soft magnetic α-Fe phase were changed independently from 10 nm to 40 nm. The results show that when the grain size of both hard and soft phases is 10 nm and the volume fraction of the hard phase is 70%, the highest maximum magnetic energy product can be obtained in both Ce2Fe14B/α-Fe and Nd2Fe14B/α-Fe nanocomposites. The hard magnetic properties of Ce2Fe14B/α-Fe nanocomposite decrease significantly when the volume fraction of the α-Fe phase exceeds 30%. However, for the Nd2Fe14B/α-Fe system, this situation only occurs when the α-Fe volume fraction exceeds 40%. The reason for this is not only because of the low anisotropic field and the smaller exchange coupling length between the soft and hard magnetic phases, but also because of the lower saturation magnetization of the hard phase. The grain size has greater effects on the magnetic properties compared to the volume fraction of the hard magnetic phase. The main reason is that as the grain size increases, the remanence of the nanocomposite decreases sharply, which also leads to a rapid decrease in the maximum magnetic energy product. The simulation results on the effects of phase ratio and grain size have been verified by experiments on melt-spun Ce2Fe14B/α-Fe alloys with various compositions prepared by melt-spinning followed by annealing for various lengths of time. Due to the influence of demagnetization energy, the hard magnetic phase with high saturation magnetization is preferred for the preparation of high-performance nanocomposite magnets. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
254. Solution-Grown trans-Stilbene Single Crystal and Its Scintillation Properties.
- Author
-
Lyasnikova, M. S., Kulishov, A. A., Yurasik, G. A., Postnikov, V. A., Karakash, A. I., and Voloshin, A. E.
- Subjects
- *
SINGLE crystals , *SCINTILLATORS , *X-rays , *SCINTILLATION counters , *STILBENE derivatives , *STILBENE , *RESEARCH personnel , *PHOTOLUMINESCENCE - Abstract
trans-Stilbene single crystals are of great interest for researchers as scintillators characterized by a high specific light yield. Bulk trans-stilbene single crystals have been grown from an anisole solution. The transmission and photoluminescence spectra have been recorded, and the single-crystal photoluminescence quenching kinetics has been investigated. The scintillation properties of an element (17 × 12 × 5 mm in size) prepared from a grown trans-stilbene crystal, irradiated by γ radiation and X rays, have also been investigated. It is shown that the specific light yield of the obtained crystal is no less than that of a scintillation detector based on a trans-stilbene crystal (31.5 × 10 mm) grown from melt. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
255. Optical and X-ray Spectroscopy of Color Centers in Cerium-Doped Yttrium‒Aluminum Garnet.
- Author
-
Butashin, A. V., Venevtsev, I. D., Fedorov, V. A., Muslimov, A. E., Antonov, E. V., Deryabin, A. N., Kvartalov, V. B., and Kanevsky, V. M.
- Subjects
- *
OPTICAL spectroscopy , *X-ray spectroscopy , *GARNET , *SINGLE crystals , *LUMINESCENCE quenching , *SCINTILLATORS , *ND-YAG lasers - Abstract
Yttrium‒aluminum garnet single crystals, including cerium-doped ones, have been grown from melt by Bagdasarov's method. A comparative spectroscopy study of garnet single crystals and specially prepared ceramics of the same composition has been carried out. The comparative analysis suggests that an increase in the concentration of cerium ions in the garnet crystals improves the spectral-luminescence and scintillation characteristics of the latter and facilitates effective quenching of the substrate luminescence. Ways of optimizing the synthesis conditions to improve the efficiency of scintillators based on {Y Cex}3Al5O12 garnet crystal have been proposed. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
256. Improved epitaxy of CsI(Tl) film on Si substrate buffered by graphene for X-ray detection.
- Author
-
Tian, Chunhui, Liu, Shuang, Xie, Yijun, Guo, Lina, Wu, Shenglan, Liu, Xixi, Chen, Dejun, Zhang, Shangjian, Liu, Yong, and Zhong, Zhiyong
- Subjects
- *
SCINTILLATORS , *X-ray detection , *GRAPHENE , *X-ray imaging , *EPITAXY , *TRANSFER functions - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
257. Luminescence and energy transfer mechanism in Ce[formula omitted] and Gd[formula omitted] ions in bismuth borate glass.
- Author
-
Fayaz, Muhammad, Ali, Shahid, Bibi, Salma, Iqbal, Yaseen, Ali, Muhammad, Zaman, Falak, Rooh, Gul, and Kaewkhao, J.
- Subjects
- *
BORATE glass , *CERIUM oxides , *ENERGY transfer , *EFFICIENCY of photovoltaic cells , *FOURIER transform infrared spectroscopy , *BISMUTH , *SILVER clusters , *SCINTILLATORS - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
258. Mn2+‐Based Luminescent Metal Halides: Syntheses, Properties, and Applications.
- Author
-
Liang, Dehai, Xiao, Hongbin, Cai, Wensi, Lu, Shirong, Zhao, Shuangyi, Zang, Zhigang, and Xie, Lei
- Subjects
- *
METAL halides , *QUANTUM efficiency , *LIGHT emitting diodes , *SCINTILLATORS , *PHOTOCATHODES - Abstract
Lead‐free metal halides are considered a new generation of optoelectronic materials due to their low toxicity, superior optoelectronic properties, ease of synthesis, structural diversity, and low cost. In particular, Mn2+‐based metal halides have earned intensive attention owing to their high emission quantum efficiency, rich physical properties (e.g., triboluminescence and stimuli‐responsivity), low cost, and toxicity. Due to the different coordination environments of Mn ions, Mn2+‐based metal halides can exhibit green, red, and near‐infrared emissions. This review summarizes the recent progress of Mn2+‐based metal halides in synthesis methods, emission mechanisms, photophysical properties, and representative applications in X‐ray scintillations, white light‐emitting diodes, optical anti‐counterfeiting technologies, and fluorescent sensors. Finally, the challenges and potential research directions toward developing Mn2+‐based metal halides are also predicted. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
259. Light Inorganic Scintillation Materials for Neutron and Charge Particle Detection.
- Author
-
Korzhik, Mikhail, Komendo, Ilia, Fedorov, Andrei, Bondaray, Alexey, Kuznetsova, Daria, Mechinsky, Vitaly, and Vasil'ev, Andrei
- Subjects
- *
SCINTILLATORS , *NEUTRON counters , *NEUTRON temperature , *RARE earth oxides , *NEUTRONS , *CARRIER density - Abstract
The technological aspects of the light inorganic crystalline compounds suitable to create scintillation materials to detect charged particles and neutrons in a wide energy range have been examined. Among them, Li2CaSiO4:Eu was found to be a prospective candidate to control the valent state of the Rare Earth (RE) and to provide a high intensity of luminescence. It was demonstrated that the material has room for future improvement; however, this requires precise engineering of its composition—an experimental search of compositions or additives that will provide the maximum Eu2+/Eu3+ ratio to achieve a high scintillation light yield. The benefits of light inorganic materials are disclosed through the modeling of the linear density of nonequilibrium carriers along secondary particle tracks created in scintillators utilized for neutron detection. It is shown that oxide matrices have a larger linear density in comparison with halide crystalline compounds under alpha-particles and tritons, whereas light oxides can provide smaller numbers under protons. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
260. A tailor-made double-tapered fibre array enables the state-of-the-art scintillators.
- Author
-
Xu, Xiuwen, Cao, Jie, Peng, Dengfeng, and Chen, Bing
- Subjects
- *
FIBERS , *SCINTILLATORS - Published
- 2023
- Full Text
- View/download PDF
261. The Influence of Halide Ion Substitution on Energy Structure and Luminescence Efficiency in CeBr 2 I and CeBrI 2 Crystals.
- Author
-
Przystupa, Krzysztof, Chornodolskyy, Yaroslav M., Selech, Jarosław, Karnaushenko, Vladyslav O., Demkiv, Taras M., Kochan, Orest, Syrotyuk, Stepan V., and Voloshinovskii, Anatolii S.
- Subjects
- *
ION energy , *CONDUCTION bands , *ENERGY bands , *LUMINESCENCE , *CRYSTALS , *VALENCE bands , *SCINTILLATORS , *BAND gaps - Abstract
This study aims to determine the optimum composition of the CeBr1−xIx compound to achieve the maximum light output. It is based on calculations of the band energy structure of crystals, specifically taking into account the characteristics of the mutual location of local and band 5d states of the Ce3+ ions. The band energy structures for CeBr2I and CeBrI2 crystals were calculated using the projector augmented wave method. The valence band was found to be formed by the hybridized states of 4p Br and 5p I. The 4f states of Ce3+ are located in the energy forbidden band gap. The conduction band is formed by the localized 5d1 states, which are created by the interaction between the 5d states of Ce3+ and the 4f0 hole of the cerium ion. The higher-lying delocalized 5d2 states of Ce3+ correspond to the energy levels of the 5d states of Ce3+ in the field of the halide Cl0 (Br0) hole. The relative location of 5d1 and 5d2 bands determines the intensity of 5d–4f luminescence. The bottom of the conduction band is formed by localized 5d1 states in the CeBr2I crystal. The local character of the bottom of the conduction band in the CeBr2I crystal favors the formation of self-trapped Frenkel excitons. Transitions between the 5d1 and 4f states are responsible for 5d–4f exciton luminescence. In the CeBrI2 crystal, the conduction band is formed by mixing the localized 5d1 and delocalized 5d2 states, which leads to quenching the 5d–4f luminescence and a decrease in the light output despite the decrease in the forbidden band gap. CsBr2I is the optimum composition of the system to achieve the maximum light output. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
262. A Novel Method for Developing Thin Resin Scintillator Screens and Application in an X-ray CMOS Imaging Sensor.
- Author
-
Linardatos, Dionysios, Fountos, George, Valais, Ioannis, and Michail, Christos
- Subjects
- *
SCINTILLATORS , *COMPLEMENTARY metal oxide semiconductors , *CMOS image sensors , *X-ray imaging , *ELECTROSTATIC discharges - Abstract
Scintillating screens for X-ray imaging applications are prepared with various methods. Among them, the classic sedimentation method presents certain weak points. In this context, a novel fabrication process was developed that offers simplicity, economy of resources and time, while the screens exhibit adequate durability and image quality performance. The proposed technique involves a resin mixture that contains the phosphor in powder form (Gd2O2S:Tb in the present work) and graphite. The novel method was optimized and validated by coupling the screens to a complementary metal oxide semiconductor (CMOS) X-ray sensor. Indicatively, screens of two surface densities were examined; 34 mg/cm2 and 70 mg/cm2. Various established image quality metrics were calculated following the IEC 62220-1 international standard, including the detective quantum efficiency (DQE). Comparisons were carried out under the same conditions, with a sedimentation screen reported previously and a screen of wide commercial circulation (Carestream Min-R 2190). The novel screens exhibit has comparable or even better performance in image-quality metrics. The 34 mg/cm2 screen achieves a DQE 15–20% greater than its comparison counterpart, and its limiting resolution was 5.3 cycles/mm. The detector coupled to the 70 mg/cm2 screen achieved a DQE 10–24% greater than its own counterpart, and its limiting resolution was found to be 5.4 cycles/mm. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
263. TL and OSL as research tools in luminescence: Possibilities and limitations.
- Author
-
Gardenali Yukihara, Eduardo
- Subjects
- *
OPTICALLY stimulated luminescence , *THERMOLUMINESCENCE , *LUMINESCENCE , *SCINTILLATORS , *IONIZING radiation , *PHOSPHORS , *DOSIMETERS - Abstract
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]
- Published
- 2023
- Full Text
- View/download PDF
264. Zn2+ Doping in Organic Manganese(II) Bromide Hybrid Scintillators toward Enhanced Light Yield for X‐Ray Imaging.
- Author
-
Jin, Jiance, Han, Kai, Hu, Yakun, and Xia, Zhiguo
- Subjects
- *
X-ray imaging , *SCINTILLATORS , *MANGANESE , *METAL halides , *BROMIDES , *DETECTION limit - Abstract
Metal halide scintillators have drawn great interest for X‐ray imaging; however, it remains challenging to simultaneously achieve a high light yield (LY) and highly sensitive detection. Herein, Zn2+ is successfully introduced into [TPPen]2MnBr4 (TPPMB, TPPen = pentyltriphenylphosphonium) and the synthesis of [TPPen]2Mn0.9Zn0.1Br4 (TPPMZB) is designed. The LY increases from 43 000 for TPPMB to 68 000 photons MeV−1 for TPPMZB in virtue of the Zn atom doping. Additionally, the detection limit of TPPMZB is 204.1 nGy s−1, showing great improvement to that of TPPMB with the value of 696.9 nGy s−1. X‐ray imaging is realized by utilizing the large‐scale scintillator film fabricated by mixing polydimethylsiloxane with TPPMZB or TPPMB, and the spatial resolution is enlarged from 4.6 to 11.2 lp mm−1 after Zn2+‐doping. This study provides a design principle by doping engineering for enhancing the LY property of metal halide X‐ray scintillators. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
265. A homogeneity study on (Ce,Gd)3Ga2Al3O12 crystal scintillators grown by an optical floating zone method and a traveling solvent floating zone method.
- Author
-
Wu, Tong, Wang, Ling, Shi, Yun, Zhang, Qian, Xiong, Yifei, Yuan, Qiang, Li, Tongtong, Ma, Kaicheng, Wang, Hui, Fang, Jinghong, Ni, Jinqi, He, Huan, Zhou, Zhenzhen, Liu, Qian, Yu, Jianding, and Zou, Jun
- Subjects
- *
INDUCTIVELY coupled plasma atomic emission spectrometry , *SCINTILLATORS - Abstract
1 at% Ce3+-doped Gd3Ga2Al3O12 (GGAG) single crystals were grown by an optical floating zone (OFZ) method and a traveling solvent floating zone (TSFZ) method. To reveal their structure and chemical composition homogeneity, X-ray diffraction (XRD) and high-resolution inductively coupled plasma atomic emission spectrometry (ICP-AES) were conducted on the as-grown Ce:GGAG crystals at 4 different positions along the growth direction. Compared with the Ce:GGAG crystals grown by the OFZ method (Ce:GGAG-OFZ), the Ce:GGAG crystals grown by the TSFZ method (Ce:GGAG-TSFZ) presented better Ce3+ distribution homogeneity which varied from 0.21 to 0.29 at%. However, the segregation coefficient of Ce3+ in Ce:GGAG-OFZ was found to be higher than that in Ce:GGAG-TSFZ, revealing a different solidification rate between them. The comparison study shows that the photoluminescence (PL) intensity of Ce:GGAG-TSFZ is about twice higher than that of Ce:GGAG-OFZ and the maximum light yield (LY) of 35 340 photons per MeV also occurs in the former. Trap depths were measured to be 0.70 eV and 0.98 eV by TL glow curves. The LY value of Ce:GGAG-TSFZ along the growth direction fluctuated to a lesser extent with respect to that of Ce:GGAG-OFZ; the latter decreases gradually along the growth direction. It is concluded that the TSFZ method helps to improve the homogeneity of crystal composition when growing crystals with multiple compositions or incongruent compounds. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
266. Reproducible evaluation of transposable element detectors with McClintock 2 guides accurate inference of Ty insertion patterns in yeast.
- Author
-
Chen, Jingxuan, Basting, Preston J., Han, Shunhua, Garfinkel, David J., and Bergman, Casey M.
- Subjects
- *
TRANSPOSONS , *WHOLE genome sequencing , *DETECTORS , *YEAST , *SCINTILLATORS , *EUKARYOTES , *SACCHAROMYCES cerevisiae - Abstract
Background: Many computational methods have been developed to detect non-reference transposable element (TE) insertions using short-read whole genome sequencing data. The diversity and complexity of such methods often present challenges to new users seeking to reproducibly install, execute, or evaluate multiple TE insertion detectors. Results: We previously developed the McClintock meta-pipeline to facilitate the installation, execution, and evaluation of six first-generation short-read TE detectors. Here, we report a completely re-implemented version of McClintock written in Python using Snakemake and Conda that improves its installation, error handling, speed, stability, and extensibility. McClintock 2 now includes 12 short-read TE detectors, auxiliary pre-processing and analysis modules, interactive HTML reports, and a simulation framework to reproducibly evaluate the accuracy of component TE detectors. When applied to the model microbial eukaryote Saccharomyces cerevisiae, we find substantial variation in the ability of McClintock 2 components to identify the precise locations of non-reference TE insertions, with RelocaTE2 showing the highest recall and precision in simulated data. We find that RelocaTE2, TEMP, TEMP2 and TEBreak provide consistent estimates of ∼ 50 non-reference TE insertions per strain and that Ty2 has the highest number of non-reference TE insertions in a species-wide panel of ∼ 1000 yeast genomes. Finally, we show that best-in-class predictors for yeast applied to resequencing data have sufficient resolution to reveal a dyad pattern of integration in nucleosome-bound regions upstream of yeast tRNA genes for Ty1, Ty2, and Ty4, allowing us to extend knowledge about fine-scale target preferences revealed previously for experimentally-induced Ty1 insertions to spontaneous insertions for other copia-superfamily retrotransposons in yeast. Conclusion: McClintock (https://github.com/bergmanlab/mcclintock/) provides a user-friendly pipeline for the identification of TEs in short-read WGS data using multiple TE detectors, which should benefit researchers studying TE insertion variation in a wide range of different organisms. Application of the improved McClintock system to simulated and empirical yeast genome data reveals best-in-class methods and novel biological insights for one of the most widely-studied model eukaryotes and provides a paradigm for evaluating and selecting non-reference TE detectors in other species. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
267. A time-based double-sided readout concept of 100 mm LYSO:Ce,Ca fibres for future axial TOF-PET.
- Author
-
Weindel, Konstantin, Nadig, Vanessa, Herweg, Katrin, Schulz, Volkmar, and Gundacker, Stefan
- Subjects
- *
PHOTOMULTIPLIERS , *SCINTILLATORS , *POSITRON emission tomography , *FIBERS , *MAGNETIC resonance imaging , *IMAGING systems , *SPATIAL resolution - Abstract
Background: Positron emission tomography (PET) requires a high signal-to-noise ratio (SNR) to improve image quality, with time-of-flight (TOF) being an effective way to boost the SNR. However, the scanner sensitivity and resolution must be maintained. The use of axially aligned 100-mm LYSO:Ce,Ca scintillation crystals with double-sided readout has the potential of ground-breaking TOF and sensitivity, while reducing parallax errors through depth-of-interaction (DOI) estimation, and also allowing a reduction in the number of readout channels required, resulting in cost benefits. Due to orientation, these fibres may also facilitate the integration of TOF-PET with magnetic resonance imaging (MRI) in hybrid imaging systems. The challenge of achieving a good spatial resolution with such long axial fibres is directly related to the achievable TOF resolution. In this study, the timing performance and DOI resolution of emerging high-performance materials were investigated to assess the merits of this approach in organ-dedicated or total-body/large-scale PET imaging systems. Methods: LYSO:Ce,Ca scintillation fibres of 20 mm and 100 mm length were tested in various operating and readout configurations to determine the best achievable coincidence time resolution (CTR) and DOI resolution. The tests were performed using state-of-the-art high-frequency (HF) readout and commercially available silicon photomultipliers (SiPMs) from Broadcom Inc. Results: For the 100-mm fibre, an average CTR performance of 137 ± 1 ps FWHM and an average depth-of-interaction resolution within the fibre of 12.3 ± 0.5 mm FWHM could be obtained. The 20-mm fibre showed a sub-100 ps CTR of 98 ± 1 ps FWHM and a fibre resolution of 8.5 ± 0.2 mm FWHM in the double-sided readout configuration. Conclusion: With modern SiPMs and crystals, a double-sided readout of long fibres can achieve excellent timing resolution and field-advancing TOF resolution, outperforming commercial PET systems. With 100-mm fibres, an electronic channel reduction of about a factor 2.5 is inherent, with larger reduction factors conceivable, which can lead to lower production costs. The spatial resolution was shown to be limited in the axial direction with 12 mm, but is defined to 3 mm in all other directions. Recent SiPM and scintillator developments are expected to improve on the time and spatial resolution to be investigated in future prototypes. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
268. Upgrade of the scintillator detector for particle tracking in experiments with antiprotons.
- Author
-
Costantini, Giovanni, Gosta, Giulia, Leali, Marco, Mascagna, Valerio, Migliorati, Stefano, Venturelli, Luca, Prest, Michela, Ronchetti, Federico, Solazzi, Luigi, and Vallazza, Erik
- Subjects
- *
NUCLEAR track detectors , *ANTIPROTONS , *COSMIC rays , *PHOTOMULTIPLIERS , *COLLISION spectroscopy , *ATOMIC spectroscopy , *SCINTILLATORS - Abstract
Experiments with antiprotons often require the tracking of charged particles emerging from the annihilation process. The Atomic Spectroscopy And Collisions Using Slow Antiprotons (ASACUSA) collaboration at the CERN Antiproton Decelerator (AD) used several panels of scintillating bars placed around the interaction region to detect the passage of charged pions and determine the annihilation vertex position and time. The panels were composed by extruded scintillating bars and the light was collected using WaveLength Shifting (WLS) fibers and multi-anode PhotoMultiplier Tubes (PMTs). After operating for several years, the fiber-PMT coupling quality had degraded and a major upgrade of the light readout system was planned. The PMTs will be replaced by Silicon PhotoMultipliers (SiPMs) and the front-end electronics changed accordingly. An improvement is expected in the efficiency and the uniformity of the detector response. In this contribution the commissioning of the upgrade will be described, including the results of preliminary tests with cosmic rays. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
269. Singlet Fission‐Based High‐Resolution X‐Ray Imaging Scintillation Screens.
- Author
-
Wang, Jian‐Xin, Yin, Jun, Gutiérrez‐Arzaluz, Luis, Thomas, Simil, Shao, Wenyi, Alshareef, Husam N., Eddaoudi, Mohamed, Bakr, Osman M., and Mohammed, Omar F.
- Subjects
- *
SCINTILLATORS , *X-ray imaging , *DELAYED fluorescence , *MEDICAL radiography , *HIGH resolution imaging , *MEDICAL screening - Abstract
X‐ray imaging technology is critical to numerous different walks of daily life, ranging from medical radiography and security screening all the way to high‐energy physics. Although several organic chromophores are fabricated and tested as X‐ray imaging scintillators, they generally show poor scintillation performance due to their weak X‐ray absorption cross‐section and inefficient exciton utilization efficiency. Here, a singlet fission‐based high‐performance organic X‐ray imaging scintillator with near unity exciton utilization efficiency is presented. Interestingly, it is found that the X‐ray sensitivity and imaging resolution of the singlet fission‐based scintillator are dramatically improved by an efficient energy transfer from a thermally activated delayed fluorescence (TADF) sensitizer, in which both singlet and triplet excitons can be efficiently harnessed. The fabricated singlet fission‐based scintillator exhibits a high X‐ray imaging resolution of 27.5 line pairs per millimeter (lp mm−1), which exceeds that of most commercial scintillators, demonstrating its high potential use in medical radiography and security inspection. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
270. Preliminary results from a study of luminescent materials—For application in the beam imaging system at the ESS.
- Author
-
Frost, R.J.W., Thomas, C.A., Elfman, M., Johansson, R., Hartl, M., Kocevar, H., Michel, K., Joshi, S., and Björklund, S.
- Subjects
- *
IMAGING systems , *SCINTILLATORS , *PROTON beams , *FLAME spraying , *STAINLESS steel , *ALUMINUM oxide - Abstract
As part of the development of the beam imaging system at the European Spallation Source, luminescent screens have been fabricated by the flame spraying of scintillating materials onto stainless steel backings. A total of seven screens were produced, three of chromia alumina (Al 2 O 3 :Cr), two of YAG (Y 3 Al 5 O 12 :Ce) and two of a 50/50 mix of these. The properties of these screens under proton irradiation were evaluated using a 2.55 MeV proton beam at currents of up to 10 μ A. Irradiation times were up to 25 h per sample, during which luminescence-, spectrographic-, thermal- and current-data was sampled at a rate of 1 Hz. Preliminary results of these measurements are reported here; with a quantitative analysis presented for one of the chromia alumina screens and a qualitative comparison of all three material types. The luminescent yield for chromia alumina was determined to be around 2000 photons/MeV for a virgin screen, and was found to drop to 1.5% after 167 mC of proton irradiation. A recovery of the luminescence of chromia alumina to >60% was observed after beam current was reduced for an 8 h period. Observations indicate that the YAG and mixed composition screens retain higher luminescence than the chromia alumina even at temperatures of over 200 °C. It is indicated that the luminescence from YAG feeds the R-lines of chromia alumina in the mixed composition screens. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
271. Impact of supporting substrate on the measured neutron yields from natLi (p, n) system: A case study with natC and natTa stopping targets.
- Author
-
Paul, Sabyasachi, Sahoo, G. S., Tripathy, S. P., and Kulkarni, M. S.
- Subjects
- *
PROTON beams , *NEUTRONS , *NEUTRON temperature , *NEUTRON emission , *NEUTRON spectrometers , *NEUTRON irradiation , *RADIATION protection , *SCINTILLATORS - Abstract
The high energy neutron generation facilities worldwide uses the Li(p,n) system for production of the quasi mono-energetic neutrons from epithermal to few hundreds of MeV. Among the facilities either self-standing thick Li target or Li foil supported on a target assembly is used. In case of a supported Li target, either low or high mass supporting substrates like Al, C, Au, Ta etc. can be used. However, the neutron emission from the supporting substrate can interfere with the Li(p,n) reaction neutrons. In the present study neutron yields from a thin natural Li target supported on the thick natural Ta (high Z) and C (low Z) targets were measured at incident proton energies between 8-20 MeV. The proton irradiation of targets were performed at the Pelletron accelerator Facility, Mumbai and the emitted neutrons were measures at both forward (0°) and lateral (90°) directions with respect to the incident beam. The neutron yield was estimated using the CR-39 detectors and dual scintillator based active neutron spectrometer. A neutron dose equivalent (NDE) meter was also used to measure the neutron ambient dose equivalent at the measurement point. Experimentally measured neutron yields and ambient neutron dose equivalent estimates indicated higher Li(p,n) neutron yield with carbon as the supporting substrate. This is due to fewer self-emissions from natC compared to natTa target. Carbon supporting substrate also ensures improved spectral features of the Li(p,n) emission neutrons and lesser neutron fluence around the source location. This ensures efficient implementation of radiation protection practices with carbon target due to lower neutron fluence around the source compared to tantalum target. Carbon is a favorable supporting substrate compared to high Z-metal targets like Ta for emission neutron studies on Li target at proton energies between 8-20 MeV. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
272. Performance of the MALTA telescope.
- Author
-
van Rijnbach, Milou, Gustavino, Giuliano, Allport, Phil, Tortajada, Ignacio Asensi, Berlea, Dumitru Vlad, Bortoletto, Daniela, Buttar, Craig, Charbon, Edoardo, Dachs, Florian, Dao, Valerio, Dobrijevic, Dominik, de Acedo, Leyre Flores Sanz, Gabrielli, Andrea, Gazi, Martin, Gonella, Laura, Gonzalez, Vicente, Guidon, Stefan, LeBlanc, Matt, Pernegger, Heinz, and Piro, Francesco
- Subjects
- *
SURFACE plates , *VERY large array telescopes , *SCINTILLATORS , *COMBINATORICS , *MULTIPLICITY (Mathematics) - Abstract
MALTA is part of the Depleted Monolithic Active Pixel sensors designed in Tower 180 nm CMOS imaging technology. A custom telescope with six MALTA planes has been developed for test beam campaigns at SPS, CERN, with the ability to host several devices under test. The telescope system has a dedicated custom readout, online monitoring integrated into DAQ with realtime hit map, time distribution and event hit multiplicity. It hosts a dedicated fully configurable trigger system enabling to trigger on coincidence between telescope planes and timing reference from a scintillator. The excellent time resolution performance allows for fast track reconstruction, due to the possibility to retain a low hit multiplicity per event which reduces the combinatorics. This paper reviews the architecture of the system and its performance during the 2021 and 2022 test beam campaign at the SPS North Area. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
273. Photoluminescent and Scintillating Performance of Eu 3+ -Doped Boroaluminosilicate Glass Scintillators.
- Author
-
Gong, Yujia, Li, Lianjie, Chen, Junyu, and Guo, Hai
- Subjects
- *
PHOTODETECTORS , *SCINTILLATORS , *X-ray imaging , *GLASS , *SINGLE crystals , *ION emission - Abstract
In comparison with single crystal scintillators, glass scintillators are more promising materials for their benefits of easy preparation, low cost, controllable size, and large-scale manufacture. The emission of Eu3+ ion at 612 nm matches well with the photoelectric detector, making it suitable for the activator in glass scintillators. Therefore, the research on Eu3+ doped glass scintillators attract our attention. The photoluminescent and scintillating properties of Eu3+-activated boroaluminosilicate glass scintillators prepared by the conventional melt-quenching method were investigated in this work. The glass samples present good internal quantum yield. Under X-ray radiation, the optimal sample reveals high X-ray excited luminesce (XEL), and its integrated intensity of XEL is 22.7% of that of commercial crystal scintillator Bi4Ge3O12. Furthermore, the optimal specimen possesses a spatial resolution of 14 lp/mm in X-ray imaging. These results suggest that Eu3+-doped boroaluminosilicate glass is expected to be applied in X-ray imaging. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
274. Scintillation Properties of Ba 3 RE(PO 4) 3 Single Crystals (RE = Y, La, Lu).
- Author
-
Takebuchi, Yuma, Koshimizu, Masanori, Ichiba, Kensei, Kato, Takumi, Nakauchi, Daisuke, Kawaguchi, Noriaki, and Yanagida, Takayuki
- Subjects
- *
SINGLE crystals , *SCINTILLATORS , *X-ray powder diffraction , *DECAY constants , *X-ray diffraction measurement , *LUTETIUM compounds - Abstract
Eulytite-type Ba3RE(PO4)3 (RE = Y, La, and Lu) single crystals were synthesized by the floating zone method, and their scintillation properties were investigated. The powder X-ray diffraction measurement revealed that the single phase of Ba3RE(PO4)3 samples were successfully synthesized. The samples exhibited a luminescence peak due to self-trapped exciton at around 400 nm under vacuum ultraviolet and X-ray irradiation. The X-ray-induced scintillation decay time constants of the samples were several microseconds at room temperature. In the 241Am α-ray irradiated pulse height spectra, all the samples showed a clear full energy peak, and the absolute light yields of the Ba3Y(PO4)3, Ba3La(PO4)3, and Ba3Lu(PO4)3 single crystals were estimated to be 960, 1160, and 1220 ph/5.5 MeV-α, with a typical error of ±10%, respectively. The scintillation light yields of the Ba3RE(PO4)3 have been quantitatively clarified for the first time. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
275. Technical note: Angular dependence in fiber optic dosimetry using YVO4:Eu3+.
- Author
-
Martínez, Nahuel, Fernández, Yohanna, Machello, Soledad, Molina, Pablo, Massa, José, and Santiago, Martín
- Subjects
- *
PHOTON beams , *LINEAR accelerators , *CHERENKOV radiation , *SCINTILLATORS , *LIGHT filters , *MONTE Carlo method , *OPTICAL fibers , *PHOTOMULTIPLIERS - Abstract
Background: Fiber optic dosimetry (FOD) has emerged as a useful technique that can be used in those cases when intracavitary, real time, high spatial resolution dose assessment is required. Among the several factors characterizing a dosimeter, angular response of FOD probes has to be assessed in order to consider possible clinical application. Purpose: The objective of this study was to characterize the angular response of a FOD probe based on a cylindrical shaped YVO4:Eu3+ scintillator under irradiation with a 6 MV photon beam generated by a linear accelerator (LINAC). Methods: A FOD probe was irradiated inside a plastic phantom using a 6 MV LINAC photon beam at different azimuthal angles (0° to 360°, 15° steps). Scintillation output was measured with a photomultiplier tube. Similar measurements were performed with a second FOD probe having an optical filter interposed between the scintillator and the fiber. Monte Carlo simulations using PENELOPE were carried out in order to interpret the observed results. Results: The FOD output was symmetrical with respect to the scintillator axis. For the unfiltered probe, the signal was maximum at rear incidence (0°) and steadily decreased down to its minimum value at frontal incidence (180°) having a signal ratio of 37%. The output of the filtered probe showed a plateau from 15° up to 115°. The signal was maximum at 60° and minimum at 180° having a signal ratio of 16%. Monte Carlo simulations predicted symmetry of the deposited dose about 0° and 90°, which contrasts with experimental findings. Conclusions: Photoluminescence (PL) of the scintillator induced by the Cherenkov light increases the angular dependence. Radiation attenuation inside the scintillator and partial light collection of the scintillation yield by the optical fiber (OF) are responsible for asymmetrical response. Results from this study should be considered in order to minimize angular dependence in FOD. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
276. LOW-BACKGROUND EXPERIMENT TO SEARCH FOR DOUBLE BETA DECAY OF 106Cd USING 106CdWO4 SCINTILLATOR.
- Author
-
Belli, P., Bernabei, R., Cappella, F., Caracciolo, V., Cerulli, R., Danevich, F. A., Inchicchitti, A., Kasperovych, D. V., Klavdiienko, V. R., Kobychev, V. V., Leoncini, A., Merlo, V., Polischuk, O. G., and Tretyak, V. I.
- Subjects
- *
DOUBLE beta decay , *NEUTRINOLESS double beta decay , *SCINTILLATORS , *SCINTILLATION counters , *MONTE Carlo method , *RADIOACTIVE contamination - Abstract
An experiment to search for 2ε-, εβ+ - and 2β+ -decays of 106Cd, using a 215 g cadmium tungstate scintillation crystal enriched at 66 % by 106Cd (106CdWO4) is carried out at the Gran Sasso underground laboratory (Italy). Events in the 106CdWO4 detector are recorded in (anti)coincidences with two large-volume CdWO4 scintillation counters. The design of the detector system, calibration and background measurements, methods, and results of data analysis to determine key detector characteristics are described. The experimental data are compared with Monte Carlo simulation results, and a background model is constructed. The radioactive contamination of the setup components is studied. The sensitivity of the experiment approaches the level of theoretical predictions for the 2Vεβ + -decay channel, while for other possible 2β-decay channels it is already on the level of lim T1/2 ~ 1021 - 1022 years. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
277. HIGH-SPEED X-RAY RADIOGRAPHY FOR EXPERIMENTS IN IMPACT DYNAMICS USING HIGH-POWER X-RAY TUBE, CESIUM IODINE SCINTILLATOR AND LABORATORY OPTICAL CAMERA.
- Author
-
ŠLEICHRT, JAN, FALTA, JAN, and FÍLA, TOMÁŠ
- Subjects
- *
RADIOGRAPHY , *SCINTILLATORS , *MACHINE learning , *MECHANICAL behavior of materials , *ARTIFICIAL neural networks - Abstract
X-ray radiography and computed tomography have become well-established methods for investigation of internal structure of objects and for defectoscopy. Recently, the methods have even been used for in-situ analysis of materials under mechanical loading. Although the techniques would be very suitable for analysis during dynamic events, their application is constrained by typical achievable frame rates. Therefore, fast imaging is usually limited to facilities providing sufficient flux like particle accelerators. In this paper, we test imaging performance of a laboratory-based setup with a high-power X-ray tube, a scintillation panel, and an optical camera. Fast-rotating object and typical specimens for impact testing are irradiated with different power settings and quality of captured images is evaluated and analyzed. It is found out that the system can be successfully used for imaging at several hundred frames per second allowing for inspection of slow impact dynamics experiments. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
278. Functional Characterization of Lysophospholipids by Proteomic and Lipidomic Analysis of Fibroblast-like Synoviocytes.
- Author
-
Timm, Thomas, Hild, Christiane, Liebisch, Gerhard, Rickert, Markus, Lochnit, Guenter, and Steinmeyer, Juergen
- Subjects
- *
LIQUID scintillation counting , *PROTEOMICS , *KNEE joint , *LYSOPHOSPHOLIPIDS , *JOINTS (Anatomy) , *PHOSPHOLIPIDS , *SCINTILLATORS - Abstract
Synovial fluid (SF) from human knee joints with osteoarthritis (OA) has elevated levels of lysophosphatidylcholine (LPC) species, but their functional role is not well understood. This in vitro study was designed to test the hypothesis that various LPCs found elevated in OA SF and their metabolites, lysophosphatidic acids (LPAs), modulate the abundance of proteins and phospholipids (PLs) in human fibroblast-like synoviocytes (FLSs), with even minute chemical variations in lysophospholipids determining the extent of regulation. Cultured FLSs (n = 5–7) were treated with one of the LPC species, LPA species, IL-1β, or a vehicle. Tandem mass tag peptide labeling coupled with LC-MS/MS/MS was performed to quantify proteins. The expression of mRNA from regulated proteins was analyzed using RT-PCR. PL synthesis was determined via ESI-MS/MS, and the release of radiolabeled PLs was determined by means of liquid scintillation counting. In total, 3960 proteins were quantified using multiplexed MS, of which 119, 8, and 3 were significantly and reproducibly regulated by IL-1β, LPC 16:0, and LPC 18:0, respectively. LPC 16:0 significantly inhibited the release of PLs and the synthesis of phosphatidylcholine, LPC, and sphingomyelin. Neither LPC metabolite—LPA 16:0 nor LPA 18:0—had any reproducible effect on the levels of each protein. In conclusion, small chemical variations in LPC species can result in the significantly altered expression and secretion of proteins and PLs from FLSs. IL-1β influenced all proteins that were reproducibly regulated by LPC 16:0. LPC species are likely to modulate FLS protein expression only in more advanced OA stages with low IL-1β levels. None of the eight proteins being significantly regulated by LPC 16:0 have been previously reported in OA. However, our in vitro findings show that the CD81 antigen, calumenin, and B4E2C1 are promising candidates for further study, focusing in particular on their potential ability to modulate inflammatory and catabolic mechanisms. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
279. Organic Cation Design of Manganese Halide Hybrids Glass toward Low‐Temperature Integrated Efficient, Scaling, and Reproducible X‐Ray Detector.
- Author
-
Xu, Youkui, Li, ZhenHua, Peng, Guoqiang, Qiu, Fu, Li, Zhizai, Lei, Yutian, Deng, Yujie, Wang, Haoxu, Liu, Zitong, and Jin, Zhiwen
- Subjects
- *
MANGANESE , *X-rays , *DETECTORS , *X-ray detection , *METAL halides , *SCINTILLATORS , *IRRADIATION , *GAMMA rays - Abstract
Zero‐dimensional (0D) structure‐based manganese metal halides (MHs) are believed to be the most promising candidates for the next‐generation X‐ray scintillators due to their intense radioluminescence and environmental friendliness. However, low‐temperature (<180 °C), large‐area integration with more efficient X‐ray detection remains a tremendous challenge. Herein, from the perspective of cation (ionic liquids) structure design, the basic physical parameters of 0D MHs are regulated. And the calculations and experimental results demonstrate larger‐size cations that induce lower melting temperatures, larger exciton‐binding energies, larger ion migration energy, and tunable hardness, which are most desirable for MHscintillators. As a result, the champion materialHTP2MnBr4is achieved as glassy transparency wafer by low‐temperature (165 °C) melt‐quenching. Its application to X‐ray imaging features high spatial resolution (17.28 lp mm−1), scalability (>30 × 30 cm2), and integration with strong coupling force. Furthermore, HTP2MnBr4 glass with reproducible properties demonstrates a high light yield (38 000 photon MeV−1), excellent irradiation stability, and low detection limit (0.13 µGy s−1). The authors believe this work will provide guidance for MHscintillators to further commercial applications. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
280. Improvement of Luminescence Properties of Eulytite Single-Phase White Emitting Ca 3 Bi (PO 4) 3 : Ce 3+ /Dy 3+ Phosphor.
- Author
-
Xu, Mengjiao, Liang, Jiamin, Wang, Luxiang, Guo, Nannan, and Ai, Lili
- Subjects
- *
LUMINESCENCE , *PHOSPHORS , *ENERGY transfer , *LIGHT emitting diodes , *THERMAL stability , *TERBIUM , *SCINTILLATORS , *PHOSPHORESCENCE - Abstract
To reduce the issue of tri-primary color reabsorption, a new approach for single-phase phosphors as light-emitting diodes (LEDs) has been recommended. The structures, morphology, photoluminescence, thermal stability, and luminescence mechanism of a variety of Ca3Bi (PO4)3 (CBPO): Ce3+/Dy3+ phosphors were investigated. XRD characterization showed that all CBPO samples were eulytite structures. Furthermore, the energy transfer process from Ce3+ to Dy3+ in CBPO is systematically investigated in this work, and the color of light can be adjusted by changing the ratio of doped ions. Under UV light, energy is transferred from Ce3+-Dy3+ mainly through quadrupole-quadrupole interactions in the CBPO host, and doping with different Dy3+ concentrations tunes the emission color from blue to white. The thermal stability of the CBPO: 0.04Ce3+, 0.08Dy3+ samples is outstanding, and the CIE coordinates of the samples after emission have little effect with temperature, while their emission intensity at 423 K is as strong as that at room temperature, reaching 90%. The above results indicate that this CBPO material has great potential as a white light phosphor under near-UV excitation at the optimized concentration of Ce3+ and Dy3+. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
281. Proton Bragg curve and energy reconstruction using an online scintillator stack detector.
- Author
-
Istokskaia, Valeriia, Lefebvre, Benoit, Petringa, Giada, Cirrone, Pablo, Guarrera, Mariacristina, Giuffrida, Lorenzo, Versaci, Roberto, Olšovcová, Veronika, and Margarone, Daniele
- Subjects
- *
PROTON beams , *MONTE Carlo method , *SCINTILLATORS , *DETECTORS , *PROTONS , *ENERGY consumption - Abstract
Real-time measurement and characterization of laser-driven proton beams have become crucial with the advent of high-repetition-rate laser acceleration. Common passive diagnostics such as radiochromic film (RCF) are not suitable for real-time operation due to time-consuming post-processing; therefore, a novel approach is needed. Various scintillator-based detectors have recently gained interest as real-time substitutes to RCF—thanks to their fast response for a wide range of dose deposition rates. This work introduces a compact, scalable, and cost-effective scintillator-based device for proton beam measurements in real-time suitable for the laser–plasma environment. An advanced signal processing technique was implemented based on detailed Monte Carlo simulations, enabling an accurate unfolding of the proton energy and the depth–dose deposition curve. The quenching effect was accounted for based on Birks' law with the help of the Monte Carlo simulations. The detector was tested in a proof-of-principle experiment at a conventional cyclotron accelerating protons up to 35 MeV of energy. The signal comparison with a standard RCF stack was also performed during the test of the device, showing an excellent agreement between the two diagnostics. Such devices would be suitable for both conventional and laser-driven proton beam characterization. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
282. Crystal growth and scintillation characterizations of mixed halide scintillators K2LaBr5-xIx: Ce (x = 0, 1, 2).
- Author
-
Zhang, Xiaoqiang, Xiong, Jianhui, Wang, Haoyu, Chen, Hongbing, Pan, Shangke, and Pan, Jianguo
- Subjects
- *
SCINTILLATORS , *CRYSTAL growth , *HALIDES , *LUMINESCENCE , *PHOTOLUMINESCENCE , *X-rays - Abstract
The purpose of this research is to investigate the luminescence and scintillation properties of mixed halide scintillators K2LaBr5-xIx. The crystals of K2LaBr5-xIx:2% Ce (x = 0, 1, 2) have been synthesized by high-temperature solid-phase method and grown by vertical Bridgman method. The crystals are measured by X-ray induced luminescence spectra, optical transmittance photoluminescence spectrum, photoluminescence decay time, and pulse height spectrum. Under the UV and X-ray excitation, all of the crystal samples have typical Ce3+ double peaks corresponding to the energy level shifts of 5d1→2F5/2 and 5d1→2F7/2, with emission centers ranging from 350 to 400 nm. The photoluminescence decay time of the three crystals of K2LaBr5-xIx: Ce is about 20 ns. Under 662 keV γ-rays excitation from a 137Cs source, the energy resolution is 8.2%, 15% and 10% (FWHM), respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
283. All‐Inorganic Glass Scintillators: Scintillation Mechanism, Materials, and Applications.
- Author
-
Liu, Jiaqi, Zhao, Xudong, Xu, Yinsheng, Wu, Haodi, Xu, Xuhui, Lu, Ping, Zhang, Xianghua, Zhao, Xiujian, Xia, Mengling, Tang, Jiang, and Niu, Guangda
- Subjects
- *
SCINTILLATORS , *GLASS , *NEUTRON counters , *BIOMEDICAL materials , *DIAGNOSTIC imaging , *X-ray imaging - Abstract
Glass scintillators have several benefits compared to the currently used single or polycrystalline scintillators, including non‐hygroscopicity, mechanical ruggedness, ease of producing customizable shapes, and low‐cost synthesis. The combination of the inert glass matrix and the embedded highly scintillating center render them significant materials for medical imaging and therapy, non‐destructive probing, nuclear monitoring, and high‐energy physics. Recently, great progress has been made in exploring new kinds of glass scintillator materials, improving imaging resolution for radiation detection, and developing an enormous range of commercial products. However, the majority of efforts have been devoted to the variation of materials, while rationally designing this new family of scintillators toward expected properties and applications is still lacking. In this review, the focus is specifically on advances in glass scintillators, including the scintillation fundamentals, material designing rule, and current application status, as well as future challenges and future directions. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
284. Stable Organic Antimony Halides with Near‐Unity Photoluminescence Quantum Yield for X‐Ray Imaging.
- Author
-
Meng, Haixing, Chen, Bing, Zhu, Wenjuan, Zhou, Zijian, Jiang, Tianxiang, Xu, Xiuwen, Liu, Shujuan, and Zhao, Qiang
- Subjects
- *
X-ray imaging , *SCINTILLATORS , *PHOTOLUMINESCENCE , *ANTIMONY , *PRECIPITATION (Chemistry) , *HALIDES - Abstract
X‐ray imaging technology has been widely used in the fields of environmental monitoring, safety inspection, nondestructive examination, space exploration, and medical diagnosis, among which scintillation materials play a vital role in indirectly converting X‐ray to visible photons. Here, a zero‐dimensional organic–inorganic hybrid halide C50H44P2SbCl5 crystal is prepared via a facile antisolvent precipitation method at room temperature. The single crystal of C50H44P2SbCl5 displays a strong yellow broadband emission centered at 592 nm with a near‐unity photoluminescence quantum yield of 98.42%. Importantly, C50H44P2SbCl5 crystals show great environmental stability and irradiation stability. Radioluminescence characterization indicates that C50H44P2SbCl5 crystals exhibit a good linear response to X‐ray dose rates along with an excellent light yield of 44 460 photons MeV−1, surpassing that of commercial inorganic LuAG:Ce scintillator. The spatial resolution of the C50H44P2SbCl5‐based scintillating screen is determined to be 8.2 lp mm−1. In conjunction with polymer thin film, the excellent scintillating feature of organic–inorganic hybrid halides offers exciting opportunities for achieving high‐quality flexible X‐ray imaging. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
285. Use of nickel sphere and copper cube with 252Cf neutron source in the centre for test of nuclear data libraries ENDF/B-VII.1, ENDF/B-VIII.0, JEFF- 3.3, BROND- 3.1.
- Author
-
Jansky, Bohumil, Rejchrt, Jiri, Novak, Evzen, Schulc, Martin, Kostal, Michal, and Blokhin, Anatoly
- Subjects
- *
NEUTRON sources , *DATA libraries , *NUCLEAR counters , *SCINTILLATORS , *NUCLEAR physics experiments - Abstract
The leakage neutron spectrum measurements have been done on benchmark spherical assembly-nickel sphere with a diameter of 50 cm and a copper cube (block) with dimensions of 49.5 x 49.5 x 48 cm3 in Research Centre Rez (RC Rez). The 252Cf neutron source was placed into the centre of nickel sphere and copper cube. The proton recoil method was used for the neutron spectrum measurement using spherical hydrogen proportional detectors (HPD) with pressure of 400 and 1000 kPa (diameter of detectors is 4 cm) and scintillation stilbene (ST) detector (diam. of 1 x 1 cm). The neutron energy range of spectrometer is from 0.04 MeV to 1.3 MeV for HPD and from 1 MeV to 12 MeV for ST. The adequate MCNP neutron spectrum calculations based on data libraries ENDF/B-VII.1, ENDF/B-VIII.0, JEFF-3.3, BROND-3.1 were done and compared with the experiment, i.e., calculation to experiment ratio C/E was determined. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
286. β-delayed neutron spectroscopy of 85As with MONSTER.
- Author
-
Pérez de Rada, A., Cano-Ott, D., Martínez, T., Alcayne, V., Mendoza, E., Plaza, J., Sanchez-Caballero, A., Villamarín, D., Äystö, J., Jokinen, A., Kankainen, A., Penttilä, H., Rinta-Antila, S., Agramunt, J., Algora, A., Domingo-Pardo, C., Lerendegui-Marco, J., Taín, J.L., Banerjee, K., and Bhattacharya, C.
- Subjects
- *
NEUTRON spectroscopy , *NEUTRON emission , *SCINTILLATORS , *TIME-of-flight spectrometry , *NEUTRON temperature - Abstract
The β-delayed neutron emission in the 85As β-decay has been measured at the IGISOL facility of the Accelerator Laboratory of the University of Jyväskylä (JYFL). The complete β-decay has been studied with a setup which consists of a plastic scintillator, the MOdular Neutron time-of-flight SpectromeTER (MONSTER), and two types of γ-rays detectors (HPGe and LaBr3). The, β-delayed neutron energy distribution has been determined by unfolding the TOF spectrum with the iterative Bayesian unfolding method. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
287. Design study on the microfluidic scintillator detector using GEANT4.
- Author
-
Yusoff, Rubena, Baco, Saturi, Rahman, Abu Bakar Abd, Ghazali, Khadizah, Gabda, Darmesah, and Al-Somali, Faten
- Subjects
- *
SCINTILLATORS , *DETECTORS , *EXPERIMENTAL design , *PHOTON counting , *PHOTONS - Abstract
A novel type of scintillator detector based on microfluidic technology that is used to determine the input function in real time has been proposed. Manipulation of the microfluidic geometric designs were done to determine the optimum design that can produce meaningful photon statistics. GEANT4 simulation toolkit was used to assess the key characteristics of the microfluidic scintillator detector, particularly in optimising the photon detection. It allows users to modify geometry description, physics processes, managing hit events and detector response. Modifications were done to the scintillator thickness as well as the dimensions of the microfluidic channel lengths to examines their relationships with the number of photons detected on the SIPM. The maximum depth of the positron particle in the plastic scintillator is approximately at 2.4 mm for 18F. Reducing the thickness of plastic scintillator to 2 mm may reduce photon collection by approximately 10% for 18F. By changing the microfluidic channel length from short to longer (constant volume), there is an increase of 9% photon detection. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
288. Emerging materials and devices for efficient light generation.
- Author
-
Murai, Shunsuke, Holmes, Russell J., Lin, Jun, Anaya, Miguel, and Lozano, Gabriel
- Subjects
- *
SCINTILLATORS , *PHOSPHORS , *SCINTILLATION counters , *QUANTUM wells , *EMISSIONS (Air pollution) - Abstract
Also related to nonlinear processes, Yang I et al. i outline in another Perspective the state of the art of rare-earth-doped upconversion (UC) nano- and microparticles.[18] Specifically, authors provide the main keys that determine the luminescence efficiency of single UC systems. Our key physiological functions and economic activity depend on the constant driving force of light.[1] Over the last few decades, incandescent and fluorescent lamps have been surpassed by electroluminescent semiconductors, giving birth to a new technology, so-called Solid State Lighting (SSL). [Extracted from the article]
- Published
- 2022
- Full Text
- View/download PDF
289. Tunable vacuum ultraviolet cross-luminescence from KMgF under high pressure as potential fast-response scintillator.
- Author
-
Cadatal-Raduban, Marilou, Yamanoi, Kohei, Yoshikawa, Akira, Yokota, Yuui, Shimizu, Toshihiko, Sarukura, Nobuhiko, Togashi, Tadashi, Kondo, Akira, and Luong, Mui Viet
- Subjects
- *
SCINTILLATORS , *GREEN'S functions , *COULOMB functions , *MAGNESIUM fluoride , *DENSITY functional theory , *POTASSIUM fluoride - Abstract
We report on the potential of the potassium magnesium fluoride (KMgF) crystal as a fast-response scintillator with tunable cross-luminescence (CL) emission wavelength through high-pressure applications. By performing first-principles density functional theory calculations using the Perdew–Burke–Ernzerhof (PBE) hybrid functional including exact exchange (PBE0) and Green's function and screened Coulomb interaction approximation as implemented in the Vienna Ab initio Simulation Package using plane-wave basis sets within the projector-augmented wave method, we identify the specific valence-to-core band transition that results in the experimentally observed CL emission at 148 nm (8.38 eV) and 170 nm (7.29 eV) wavelengths with intrinsically fast decay times of 290 ps and 210 ps, respectively. Uniform volume compression through hydrostatic high-pressure applications could decrease the energy gap between the valence and core bands, potentially shifting the CL emission wavelength to the ultraviolet (UV) region from 200 nm (6.2 eV) to 300 nm (4.1 eV). The ability to tune and shift the CL emission to UV wavelengths allows for the detection of the CL emission using UV-sensitive photodetectors in ambient atmosphere instead of highly specialized vacuum UV detectors operating in vacuum while maintaining the intrinsically fast CL decay times, thereby opening up new possibilities for KMgF as a fast-response scintillator. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
290. Attaining the PeV frontier of the cosmic ray spectrum in space with HERD.
- Author
-
Perrina, Chiara
- Subjects
- *
COSMIC rays , *NUCLEAR counters , *PHYSICS , *ASTRONOMY , *SCINTILLATORS - Abstract
The High Energy cosmic-Radiation Detection facility (HERD) is a calorimetric experiment planned to be launched in 2027. It will be operational for at least 10 years on board the China Space Station. With HERD we will measure the energy flux of cosmic protons and heavier nuclei from 30 GeV up to, for the first time in space, a few PeV. We will search for signatures of annihilation and decay products of dark matter in the energy spectrum of cosmic electrons and gamma rays from 10 GeV to 100 TeV. A wide field of view monitoring of the gamma-ray full-sky from 100 MeV will also be performed. The five HERD subdetectors, the calorimeter (CALO), the scintillating fiber tracker (FIT), the plastic scintillator detector (PSD), the silicon charge detector (SCD) and the transition radiation detector (TRD), are currently under development. The design, prospects and expected performance of HERD, as well as its contribution to the multimessenger astronomy will be presented in this contribution. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
291. Desktop plastic scintillator detector as a potential single replacement for both neutron and Gamma-ray detectors.
- Author
-
Said, Asmaa, Salama, E., Radi, Amr, Khedr, H. I., and El-Aassar, M.
- Subjects
- *
NEUTRON counters , *NUCLEAR counters , *DETECTORS , *RADIATION dosimetry , *NEUTRON flux , *GAMMA rays , *SCINTILLATORS - Abstract
This work is based on the design introduced by the cosmic watch project from the Massachusetts Institute of Technology has been constructed and compromised to be used for radiation detection and dosimetry applications. This single detector is a potential replacement for neutron and gamma-ray detectors in radiation portal monitors (RPM) systems. Non-linear dose-response of this detector while exposure to gamma dose rate in the µGy/hr range is obtained while linear count rate is obtained for exposure to the neutron flux. Neutron flux distribution around the Am–Be neutron source, neutron security gating, and gamma dosimetry are three successful applications checked in this study. The obtained results recommend using this plastic scintillator as a potential single-detector replacement for both neutron and gamma-ray detectors in radiation portal monitors (RPM) systems. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
292. Wavelength-independent light extraction enhancement by nanostructures for scintillators with broadband emission.
- Author
-
Zhang, Fan, Huang, Yi, Guo, Yaozhen, Zhang, Juannan, Ouyang, Xiaoping, and Liu, Bo
- Subjects
- *
SCINTILLATORS , *NANOSTRUCTURES , *LIGHT emitting diodes , *PHOTONIC crystals , *SINGLE crystals , *WAVELENGTHS - Abstract
Conventional photonic crystals with a single period are capable of enhancing the light output of scintillators based on the partial elimination of internal total reflection. However, the enhancement often comes along with a strong wavelength dependence, leading to a severe spectrum distortion. Here, the nanostructures for wavelength-independent light extraction enhancement, namely, multi-size spherical nanostructures, are designed and fabricated. The nanostructure can efficiently outcouple the scintillation light and at the same time significantly weaken the wavelength dependence. The light output of the scintillators with the nanostructures obtains noticeable enhancement with a ratio of 1.7, having weak wavelength dependence, which is in contrast to the enhancement by single-periodic photonic crystals. In addition to the applications on the scintillators, we anticipate that these wavelength-independent light output enhancement schemes could be expanded to other important fields, such as white light-emitting diodes and display devices. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
293. Thermally Activated Delayed Fluorescence from Perovskite‐Derivative CsAgCl2 Nanocrystals for High‐Resolution X‐Ray Imaging.
- Author
-
Lin, Qun, Wang, Zhaoyu, Wei, Youchao, Chen, Yameng, Li, Xiaohan, Liu, Yongsheng, and Hong, Maochun
- Subjects
- *
DELAYED fluorescence , *X-ray imaging , *NANOCRYSTALS , *CONDUCTION bands , *HIGH resolution imaging , *X-ray detection , *SCINTILLATORS - Abstract
Thermally activated delayed fluorescence (TADF) materials hold great promise as next‐generation efficient emitters due to their theoretical 100% internal quantum efficiency. However, such an intriguing photophysical mechanism is extremely rare in perovskites or their derivatives. Herein, the colloidal synthesis of two‐dimensional CsAgCl2 nanocrystals (NCs) with typical TADF feature is reported first. The TADF mechanism is investigated in detail by combining first‐principles calculations with experimental results, including temperature‐dependent spectral analysis and fs‐transient absorption spectra. A small singlet−triplet state splitting energy (0.082 eV) and a large spatial separation of charge density |Ψ|2 of valence band maximum and conduction band minimum are observed, which are prerequisites for TADF. Moreover, these CsAgCl2 NCs deliver an ultralow X‐ray detection limit of 170.5 nGyair s−1 and a high imaging resolution of 11.5 lp mm−1, much superior to the commercial scintillators. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
294. Charge Transfer and Charge Trapping Processes in Ca- or Al-Co-doped Lu 2 SiO 5 and Lu 2 Si 2 O 7 Scintillators Activated by Pr 3+ or Ce 3+ Ions.
- Author
-
Laguta, Valentyn, Havlak, Lubomir, Babin, Vladimir, Barta, Jan, Pejchal, Jan, and Nikl, Martin
- Subjects
- *
CALCIUM ions , *LUTETIUM compounds , *SCINTILLATORS , *ELECTRON paramagnetic resonance , *CRYSTAL defects , *RADIOLUMINESCENCE , *CHARGE transfer , *ION traps , *IONS - Abstract
Lutetium oxyorthosilicate Lu2SiO5 (LSO) and pyrosilicate Lu2Si2O7 (LPS) activated by Ce3+ or Pr3+ are known to be effective and fast scintillation materials for the detection of X-rays and γ-rays. Their performances can be further improved by co-doping with aliovalent ions. Herein, we investigate the Ce3+(Pr3+) → Ce4+(Pr4+) conversion and the formation of lattice defects stimulated by co-doping with Ca2+ and Al3+ in LSO and LPS powders prepared by the solid-state reaction process. The materials were studied by electron paramagnetic resonance (EPR), radioluminescence spectroscopy, and thermally stimulated luminescence (TSL), and scintillation decays were measured. EPR measurements of both LSO:Ce and LPS:Ce showed effective Ce3+ → Ce4+ conversions stimulated by Ca2+ co-doping, while the effect of Al3+ co-doping was less effective. In Pr-doped LSO and LPS, a similar Pr3+ → Pr4+ conversion was not detected by EPR, suggesting that the charge compensation of Al3+ and Ca2+ ions is realized via other impurities and/or lattice defects. X-ray irradiation of LPS creates hole centers attributed to a hole trapped in an oxygen ion in the neighborhood of Al3+ and Ca2+. These hole centers contribute to an intense TSL glow peak at 450–470 K. In contrast to LPS, only weak TSL peaks are detected in LSO and no hole centers are visible via EPR. The scintillation decay curves of both LSO and LPS show a bi-exponential decay with fast and slow component decay times of 10–13 ns and 30–36 ns, respectively. The decay time of the fast component shows a small (6–8%) decrease due to co-doping. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
295. Li 2 100depl MoO 4 Scintillating Bolometers for Rare-Event Search Experiments.
- Author
-
Bandac, Iulian C., Barabash, Alexander S., Bergé, Laurent, Borovlev, Yury A., Calvo-Mozota, José Maria, Carniti, Paolo, Chapellier, Maurice, Dafinei, Ioan, Danevich, Fedor A., Dumoulin, Louis, Ferri, Federico, Giuliani, Andrea, Gotti, Claudio, Gras, Philippe, Grigorieva, Veronika D., Ianni, Aldo, Khalife, Hawraa, Kobychev, Vladislav V., Konovalov, Sergey I., and Loaiza, Pia
- Subjects
- *
BOLOMETERS , *MOLYBDENUM , *LITHIUM , *RADIOCHEMICAL purification , *SCINTILLATORS , *DETECTORS - Abstract
We report on the development of scintillating bolometers based on lithium molybdate crystals that contain molybdenum that has depleted into the double- β active isotope 100 Mo (Li 2 100 depl MoO 4 ). We used two Li 2 100 depl MoO 4 cubic samples, each of which consisted of 45-millimeter sides and had a mass of 0.28 kg; these samples were produced following the purification and crystallization protocols developed for double- β search experiments with 100 Mo-enriched Li 2 MoO 4 crystals. Bolometric Ge detectors were utilized to register the scintillation photons that were emitted by the Li 2 100 depl MoO 4 crystal scintillators. The measurements were performed in the CROSS cryogenic set-up at the Canfranc Underground Laboratory (Spain). We observed that the Li 2 100 depl MoO 4 scintillating bolometers were characterized by an excellent spectrometric performance (∼3–6 keV of FWHM at 0.24–2.6 MeV γ s), moderate scintillation signal (∼0.3–0.6 keV/MeV scintillation-to-heat energy ratio, depending on the light collection conditions), and high radiopurity ( 228 Th and 226 Ra activities are below a few µBq/kg), which is comparable with the best reported results of low-temperature detectors that are based on Li 2 MoO 4 using natural or 100 Mo-enriched molybdenum content. The prospects of Li 2 100 depl MoO 4 bolometers for use in rare-event search experiments are briefly discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
296. Extended Depth of Focus Two-Photon Light-Sheet Microscopy for In Vivo Fluorescence Imaging of Large Multicellular Organisms at Cellular Resolution.
- Author
-
Saitou, Takashi and Imamura, Takeshi
- Subjects
- *
MULTICELLULAR organisms , *FLUORESCENCE microscopy , *BESSEL beams , *NUMERICAL apertures , *HIGH resolution imaging , *MAGNIFICATION (Optics) , *SCINTILLATORS , *X-ray fluorescence - Abstract
Two-photon excitation in light-sheet microscopy advances applications to live imaging of multicellular organisms. In a previous study, we developed a two-photon Bessel beam light-sheet microscope with a nearly 1-mm field of view and less than 4-μm axial resolution, using a low magnification (10×), middle numerical aperture (NA 0.5) detection objective. In this study, we aimed to construct a light-sheet microscope with higher resolution imaging while maintaining the large field of view, using low magnification (16×) with a high NA 0.8 objective. To address potential illumination and detection mismatch, we investigated the use of a depth of focus (DOF) extension method. Specifically, we used a stair-step device composed of five-layer annular zones that extended DOF two-fold, enough to cover the light-sheet thickness. Resolution measurements using fluorescent beads showed that the reduction in resolutions was small. We then applied this system to in vivo imaging of medaka fish and found that image quality degradation at the distal site of the beam injection could be compensated. This demonstrates that the extended DOF system combined with wide-field two-photon light-sheet microscopy offers a simple and easy setup for live imaging application of large multicellular organism specimens with sub-cellular resolution. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
297. Effect of Ce3+ Content and Annealing Temperature on the Optical and Scintillation Properties of Ce3+‐Doped Y3Al5O12 Nanoscintillator Synthesized by Sol–Gel Route.
- Author
-
Zahra, Billel, Guerbous, Lakhdar, Bousbia-Salah, Hicham, and Boukerika, Allaoua
- Subjects
- *
SCINTILLATORS , *OPTICAL properties , *NUCLEAR counters , *PHOTOMULTIPLIERS , *NANOSTRUCTURED materials , *SOL-gel processes - Abstract
Herein, details on the effect of Ce3+ concentration and annealing temperature on luminescence and scintillation properties of Y3Al5O12:Ce3+ (YAG:Ce3+) nanoscintillator powders, prepared by sol–gel method, have been investigated. Despite extensive research on YAG:Ce3+ single crystal, the behavior of this material at the nanoscale is still not fully understood. The photoluminescence spectra of nanoscintillator powders have been measured and analyzed. To properly assess the scintillation properties, the nanoscintillator sample powders are developed for use as a radiation detector and underwent preparation procedures, including surface homogenization and efficient coupling with a photomultiplier tube window. It is shown that even with nanoscintillator powders, pulse height spectra, with well‐resolved photo‐peak from the Compton edge, and scintillation decay curves are obtained. It is found that 0.5 mol% Ce3+ sample annealed at 1000 °C presents the nonradiative quenching concentration with calculated critical distance of 20.21 Å based on the resonance transfer by electric multipole–multipole interaction. Additionally, the sample detector with 0.5 mol% Ce3+ annealed at 1150 °C exhibits the highest light yield (LY) with value 18 900 ph MeV−1 and a better energy resolution value 10% full‐width and half‐maximum under 662 keV γ‐ray from 137Cs source. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
298. First time-resolved measurement of infrared scintillation light in gaseous xenon.
- Author
-
Piotter, Mona, Cichon, Dominick, Hammann, Robert, Jörg, Florian, Hötzsch, Luisa, and Marrodán Undagoitia, Teresa
- Subjects
- *
TIME-resolved measurements , *XENON , *SCINTILLATORS , *PHOTOMULTIPLIERS , *ALPHA rays , *TIME measurements - Abstract
Xenon is a widely used detector target material due to its excellent scintillation properties in the ultraviolet (UV) spectrum. The additional use of infrared (IR) scintillation light could improve future detectors. However, a comprehensive characterization of the IR component is necessary to explore its potential. We report on the first measurement of the time profile of the IR scintillation response of gaseous xenon. Our setup consists of a gaseous xenon target irradiated by an alpha particle source and is instrumented with one IR- and two UV-sensitive photomultiplier tubes. Thereby, it enables IR timing measurements with nanosecond resolution and simultaneous measurement of UV and IR signals. We find that the IR light yield is in the same order of magnitude as the UV yield. We observe that the IR pulses can be described by a fast and a slow component and demonstrate that the size of the slow component decreases with increasing levels of impurities in the gas. Moreover, we study the IR emission as a function of pressure. These findings confirm earlier observations and advance our understanding of the IR scintillation response of gaseous xenon, which could have implications for the development of novel xenon-based detectors. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
299. Adaptive Beam Divergence Control to Mitigate Scintillation Effect Caused by Pointing Error in Vertical FSO Transmissions.
- Author
-
Park, Hye-Min, Hyun, Young-Jin, and Han, Sang-Kook
- Subjects
- *
OPTICAL transceivers , *NEXT generation networks , *FREE-space optical technology , *WEATHER , *SIGNAL-to-noise ratio , *SCINTILLATORS - Abstract
Free-space optical (FSO) communication has been studied for next-generation network systems. Because an FSO system establishes point-to-point communication links, maintaining alignment among the transceivers is a critical challenge. In addition, atmospheric turbulence causes significant signal loss in FSO vertical links. Even in clear weather conditions, transmitted optical signals suffer significant scintillation losses due to random variations. Thus, the effect of atmospheric turbulence should be considered in vertical links. In this paper, we analyze the relationship between pointing error and scintillation from the aspect of beam divergence angle. Furthermore, we propose an adaptive beam that optimizes its divergence angle according to the pointing error between the communicating optical transceivers to mitigate the effect of scintillation due to pointing error. We performed a beam divergence angle optimization and compared it with adaptive beamwidth. The proposed technique was demonstrated using simulations, which revealed an enhanced signal-to-noise ratio and the mitigation of the scintillation effect. The proposed technique would be useful in minimizing the scintillation effect in vertical FSO links. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
300. Full modulation transfer functions of thick parallel‐ and focused‐element scintillator arrays obtained by a Monte Carlo optical transport model.
- Author
-
Zarrini‐Monfared, Zinat, Karbasi, Sareh, Zamani, Ali, and Mosleh‐Shirazi, Mohammad Amin
- Subjects
- *
TRANSFER functions , *PHOTON detectors , *SCINTILLATORS , *IMAGE-guided radiation therapy , *CONE beam computed tomography , *SCINTILLATION counters , *PHOTON beams , *IMAGING systems , *LINEAR accelerators - Abstract
Background: Arrays of thick segmented crystalline scintillators are useful x‐ray converters for image‐guided radiation therapy using electronic portal imaging (EPI) and megavoltage cone‐beam computed tomography (MV‐CBCT). Ionizing‐radiation‐only simulations previously showed relatively low modulation transfer function (MTF) in parallel‐element arrays because of beam divergence. Hence, a focused‐element geometry (matching the beam divergence) has been proposed. The "full" (ionizing and optical) MTF performance of such a focused geometry compared to its radiation‐only MTF has, however, not been fully investigated. Purpose: To study the full MTF performance of such arrays in a more realistic situation in which optical characteristics are also included using an in‐house detector model that supports light transport, and quantify the errors in MTF estimation when the optical stage is ignored. Methods: First, radiation (x‐ray and electron) transport was simulated. Then, transport of the generated optical photons was modeled using ScintSim2, an optical Monte Carlo (MC) code developed in MATLAB for simulation of two‐dimensional (2D) parallel‐ and focused‐element scintillator arrays. The full‐MTF responses of focused‐ and parallel‐element geometries, for a large array of 3 × 3 mm2 CsI:Tl detector elements of 10, 40, and 60 mm thicknesses, were examined. For each configuration, a composite line spread function (LSF) was calculated to obtain the MTF. Results: At the Nyquist frequency, for 10 mm‐thick central elements and 60 mm‐thick peripheral parallel elements, full‐MTF exhibited a drop of up to 15 and 79 times, respectively, compared with radiation‐only MTF. This was found to be partly attributable to the angular distribution of the light emerging from the detector‐element exit face and the dependence on its aspect ratio, since the light exiting thicker scintillators exhibited a more forward‐directed distribution. Focused elements provided an increase of up to nine times in peripheral‐area full MTF values. Conclusions: Full MTF was up to 79 times lower than radiation‐only MTF. Focused arrays preserved full MTF by up to nine times compared to parallel elements. The differences in the results obtained with and without inclusion of optical photons emphasize the need to include light transport when optimizing thick segmented scintillation detectors. Besides their application in detector optimization for radiotherapy megavoltage photon imaging, these findings can also be useful for other segmented‐scintillator‐based imaging systems, for example, in nuclear medicine, or in 2D detection systems for quality assurance of MR‐linacs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.