Radiation Measurements最新文献

{"title":"Design of a collimator-free SPECT system based on multi-layer grid scintillator array","authors":"Xue Yang ,&nbsp;Changran Geng ,&nbsp;Lu Han ,&nbsp;Feng Tian ,&nbsp;Ningxin Dong ,&nbsp;Xiaobin Tang","doi":"10.1016/j.radmeas.2026.107631","DOIUrl":"10.1016/j.radmeas.2026.107631","url":null,"abstract":"<div><div>Traditional single-photon emission computed tomography (SPECT) systems exhibit a tradeoff between spatial resolution and sensitivity because of the use of mechanical collimators. To address this issue, this paper proposes a collimator-free SPECT detector design based on a staggered multilayer grid scintillator array, to enable image reconstruction without requiring conventional mechanical collimation. Based on the experimental and simulation results, the system parameters were evaluated and a practical configuration incorporating 25 mm-long elongated scintillators, 6 mm-thick grid layers, and 40 mm layer spacing was established. To preliminarily assess the clinical-scale system performance, a clinical-scale system featuring a 15-detector annular array with a 300 mm rotation radius was simulated to emulate realistic cardiac SPECT imaging conditions. The results demonstrated that the system had a 0.76% detection efficiency on a clinical scale (compared to 0.1% for conventional SPECT), successfully resolving point sources spaced 2 mm apart. The cylinder model imaging results demonstrated that the mean activity recovery coefficient (ARC) of the reconstructed images for each cylinder was between 0.5 and 0.6. This preliminary result validates the feasibility of a collimator-free SPECT system and lays the foundation for further improvements in reconstruction accuracy. The proposed approach offers a potentially viable solution for concurrently enhancing spatial resolution and detection sensitivity in SPECT systems, with promising applications in myocardial perfusion imaging.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"193 ","pages":"Article 107631"},"PeriodicalIF":2.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Organic glass scintillators: Material properties, performance characterization, and applications","authors":"S.A. Pozzi ,&nbsp;E. Schneider ,&nbsp;E. Neely ,&nbsp;R. Lopez ,&nbsp;P. Feng ,&nbsp;S.D. Clarke","doi":"10.1016/j.radmeas.2026.107627","DOIUrl":"10.1016/j.radmeas.2026.107627","url":null,"abstract":"<div><div>Organic Glass Scintillators (OGSs) are an emerging class of scintillator materials for advanced radiation detection applications requiring high light output and efficiency, compactness, scalability, and dual-particle detection. This paper reviews recent literature on OGSs, focusing on their properties and applications. We highlight the promising characteristics of OGS, including excellent time resolution, high light output, pulse shape discrimination (PSD) and ease of manufacturing via casting procedures, as well as their flexibility in forming pixelated arrays. Challenges include optimizing PSD at low energies and enhancing long-term stability (recrystallization). The use of OGSs in prototype detectors is being explored for fast neutron detection, compact imaging systems, and neutron spectrometry. This evaluation includes laboratory tests and preliminary applications in the field.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"193 ","pages":"Article 107627"},"PeriodicalIF":2.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146192692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of light output and energy resolution for trans-stilbene, EJ-309, and organic glass scintillators","authors":"Mairead E. Montague,&nbsp;Shaun D. Clarke,&nbsp;Sara A. Pozzi","doi":"10.1016/j.radmeas.2026.107646","DOIUrl":"10.1016/j.radmeas.2026.107646","url":null,"abstract":"<div><div>The lack of direct comparison data for new and existing scintillators is a challenge in selecting organic scintillators used in various radiation detection applications. To address this gap, we characterized three ∅2.54 by 2.54 cm cylindrical organic scintillators in the same experimental conditions: <em>trans</em>-stilbene crystalline scintillator, organic glass scintillator (OGS), and EJ-309 liquid scintillator. Using a coincident backscatter configuration with a NaI(Tl) detector and a Cs-137 source, we isolated gamma-ray backscatter events to measure and analyze the pulse integral spectra resulting from 478 keV energy depositions in each scintillator. The energy resolution at 478 keV, determined via Gaussian fits to the backscatter-gated spectra, were found to be 10.67 ± 0.32% for the <em>trans</em>-stilbene, 10.00 ± 0.28% for the OGS, and 12.46 ± 0.35% for the EJ-309. The relative light outputs, normalized to EJ-309, were 1.48 ± 0.02 for OGS, and 1.36 ± 0.03 for <em>trans-</em>stilbene. These results show that OGS offers both the highest scintillation light yield and the best energy resolution among the three scintillators in this study. While each of these scintillators has previously been studied, this is the first time they have been directly compared under the same experimental conditions allowing for direct comparisons between their energy resolution and light outputs.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"193 ","pages":"Article 107646"},"PeriodicalIF":2.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146193063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fading study of Harshaw LiF:Mg,Ti thermoluminescence dosimeters exposed to neutron doses","authors":"S. Sholom,&nbsp;B. Hooda","doi":"10.1016/j.radmeas.2026.107637","DOIUrl":"10.1016/j.radmeas.2026.107637","url":null,"abstract":"<div><div>Sensitivity and signal fading were tested in Harshaw LiF:Mg,Ti thermoluminescence dosimeters (TLDs) exposed to neutron and beta/photons doses. A significant difference in the signal fading rate was observed for TLDs exposed to neutrons compared with TLDs exposed to betas. This difference may have been related to differences in glow curves for dosimeters exposed to different beams and to differences in glow curve evolution after exposure. A fading-correction algorithm was developed to correct the cumulative sensitivity + signal fading of TL doses for the fading time t using the formulae: y = 0.147∗exp(-t/4.36) + 0.308∗exp(-t/34.1) + 0.73 for neutrons, and: y = 0.132∗exp(-t/10.72) + 0.174∗exp(-t/31.5) + 0.8 for betas/photons. The formula was validated using the dose recovery test, where the average deviation of fading-corrected doses from delivery doses was within 1%.</div><div>The proposed fading-correction approaches may significantly improve the accuracy of Harshaw TL dosimetry with LiF:Mg,Ti cards for both neutron and beta/gamma irradiation.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"193 ","pages":"Article 107637"},"PeriodicalIF":2.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146193073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Method validation for the characterization of γ-emitting radionuclides in irradiated graphite using the efficiency transfer software EFFTRAN","authors":"L. Meunier ,&nbsp;N. Heiß ,&nbsp;L. Lens ,&nbsp;D. Reiswich ,&nbsp;M. Knebel ,&nbsp;U.W. Scherer","doi":"10.1016/j.radmeas.2026.107634","DOIUrl":"10.1016/j.radmeas.2026.107634","url":null,"abstract":"<div><div>A large quantity of irradiated nuclear graphite has been produced over the years and has to be treated potentially as radioactive waste. Several challenges arise when considering final disposal of such graphite in Germany, due to the lack of information on the radionuclide inventory as well as the strict guidelines for certain radionuclides. Therefore, experimental characterization becomes essential, not only to identify the specific radionuclides present in graphite samples but also to determine their activities. Gamma emitters are of particular concern during decommissioning activities, as they are the primary contributors to the dose rate to which workers may be exposed. One commonly used technique for this purpose is gamma-ray spectrometry, which relies on an accurate efficiency curve to quantify the sample's activity. This can be achieved by using the experimental efficiency curve of a standard that has the same geometry as the sample. However, this is not always possible due to the variation in shape, size and matrix of the sample. In order to overcome this challenge, simulation software can be used, such as the Monte Carlo-based efficiency transfer code EFFTRAN. It allows the transfer of the efficiency curve from cylindrical reference standards to any other cylindrical sample. This transfer method has been validated in this work using certified standards as well as irradiated nuclear graphite samples coming from the FRJ-2 (JEN) research reactor.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"193 ","pages":"Article 107634"},"PeriodicalIF":2.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146193064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A survey of dosimetry capabilities and trends in Latin America and the Caribbean region: Implications for occupational dosimetry","authors":"Juan C. Mora ,&nbsp;Mariella Terán ,&nbsp;Helen Khoury ,&nbsp;Daniel Molina ,&nbsp;Patricia Mora ,&nbsp;Nancy Puerta ,&nbsp;Leslie Anne Vironneau Janicek ,&nbsp;Sebastian Gossio ,&nbsp;Denison de Souza-Santos ,&nbsp;Omar Garcia ,&nbsp;Julieta Rearte ,&nbsp;Marina Di Giorgio ,&nbsp;V. Correcher","doi":"10.1016/j.radmeas.2026.107636","DOIUrl":"10.1016/j.radmeas.2026.107636","url":null,"abstract":"&lt;div&gt;&lt;div&gt;This study presents a comprehensive regional assessment of dosimetry capabilities in Latin America and the Caribbean countries (LAC). The study was conducted using surveys coordinated, elaborated and analyzed by the steering committee of the Latin American Network for the Optimization of Occupational Radiation Protection (REPROLAM). All the work was supported by the Technical Cooperation of International Atomic Energy Agency (TC IAEA) through the RLA9088 and RLA9091 regional projects. The investigation covers five different dosimetry fields: external, internal, computational, biological, and retrospective dosimetry. Answers from participants of 16 countries were received: A total of 32 individual monitoring services for external dosimetry, 24 centers for internal dosimetry, 38 researchers for computational dosimetry, 12 biological dosimetry laboratories members of the Latin American Biological Dosimetry Network (LBDNet), and 16 retrospective dosimetry facilities. In the case of external dosimetry, an analysis of the results from 13 countries reveals that thermoluminescent dosimetry (TLD) remains the main technology for external monitoring (79% of services), with a growing adoption of optically stimulated luminescence dosimetry (OSLD) systems. Using both TLD and OSLD, over 160,000 occupationally exposed workers are monitored regionally, predominantly in medical applications (75%). Internal dosimetry services (16 direct, 15 indirect services) focus primarily on thyroid monitoring due to extensive &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;131&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; use in nuclear medicine in the region, but the results showed a lack of homogeneity in calibration and reporting levels. Monte Carlo-based computational dosimetry employs MCNP as the preferred code (25% of users). Biological dosimetry is well-established in the region through the LBDNet, with 21 laboratories capable of performing dicentric chromosome assays for emergency triage. LBDNet demonstrated to be a robust emergency response network. Retrospective dosimetry in the region relies predominantly on luminescence techniques. While dosimetry laboratories and techniques are well established in the region, several gaps have been identified which should be addressed in further approaches. These gaps include insufficient implementation of lens of the eye dosimetry (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;p&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;), limited neutron dosimetry capacity, poor implementation of quality management system (60% of the IMS) and insufficient ISO/IEC 17025 accreditation (70% of those implementing a QMS, i.e. 42% of the total), a lack of standardized internal dosimetry protocols in the different laboratories, and the need for organizing periodic regional intercomparison exercises, which started with the 2023 intercomparison. The results of these surveys provide a baseline","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"193 ","pages":"Article 107636"},"PeriodicalIF":2.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Summing-induced signal distortion mechanisms and suppression methods in SiPM array gamma spectroscopy detectors","authors":"Bao Wang ,&nbsp;Xiongjie Zhang ,&nbsp;Dongyang Wang ,&nbsp;Wenming Dong ,&nbsp;Dong Li ,&nbsp;Shiliang Liu ,&nbsp;Haoran Zhang ,&nbsp;Jiangni Liu ,&nbsp;Haixian Zhou ,&nbsp;Qi Liu ,&nbsp;Haitao Wang ,&nbsp;Ning Chen ,&nbsp;Renbo Wang","doi":"10.1016/j.radmeas.2026.107633","DOIUrl":"10.1016/j.radmeas.2026.107633","url":null,"abstract":"<div><div>Pulse height analysis (PHA) is commonly used in scintillation γ-ray spectroscopy because it is simple and fast. However, in systems utilizing summed outputs from multi-channel silicon photomultiplier (SiPM) arrays, PHA becomes increasingly susceptible to waveform distortions inherent to the summing architecture. Such distortions alter the signal shape and significantly degrade the energy resolution. In this study, we systematically investigate the characteristics and origins of such abnormal signals using a 16-channel SiPM array coupled to a NaI(Tl) scintillator. By analyzing the pulse area-to-height ratio distributions, we show that summing-induced distortions tend to exhibit broadened pulse shapes and deviate significantly from the single-event signal profile. To mitigate this issue, a threshold-based waveform discrimination method is introduced. This method identifies and rejects abnormal pulses based on receiver operating characteristic (ROC) curve optimization, offering practical improvement in spectral performance when PHA must be retained for speed or simplicity. However, waveform correction alone cannot restore distorted signals. To address this limitation, we further explore pulse area analysis (PAA) as an alternative approach that is inherently less sensitive to distortion effects. Our experiments show that PAA improves energy resolution by 24.25% over conventional PHA, reaching 9.40% at 662 keV. These findings highlight the limitations of amplitude-based methods under summed readout architectures and suggest that PAA, when applicable, offers a more robust solution for compact gamma spectroscopy using SiPM arrays. This work provides both theoretical insights and practical strategies for mitigating signal anomalies in modern scintillation detectors.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"193 ","pages":"Article 107633"},"PeriodicalIF":2.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Luminescent and dosimetric properties of CaSO4:RE,Mn (RE = Dy, Tb, Tm, Yb, Eu, Ce) phosphors synthesized by the slow evaporation method","authors":"Anderson M.B. Silva ,&nbsp;Danilo O. Junot ,&nbsp;Neilo M. Trindade ,&nbsp;Divanizia N. Souza ,&nbsp;Linda V.E. Caldas","doi":"10.1016/j.radmeas.2026.107624","DOIUrl":"10.1016/j.radmeas.2026.107624","url":null,"abstract":"<div><div>This study investigates the luminescent and dosimetric properties of CaSO₄:Dy,Mn, CaSO₄:Tb,Mn, CaSO₄:Tm,Mn, CaSO₄:Yb,Mn, CaSO₄:Eu,Mn and CaSO₄:Ce,Mn composites synthesized via the slow evaporation route. Structural and compositional characterization was performed using X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS). The dosimetric performance of the materials was evaluated using Teflon-based pellets through thermoluminescence (TL) glow curve measurements. Additionally, Continuous Wave Optically Stimulated Luminescence (CW-OSL) measurements were conducted to assess their optical stimulation behavior. The TL emission spectra revealed characteristic transitions associated with both RE³⁺ and Mn²⁺ ions, with emission features strongly dependent on the specific dopant. The TL glow curves exhibited well-defined peaks in the UV and visible regions, with Tm,Mn, Dy,Mn and Tb,Mn codoped samples showing enhanced emissions at higher temperatures, a desirable feature for dosimetric applications. CW-OSL measurements demonstrated intense luminescence responses, particularly for the CaSO₄:Tm,Mn and CaSO₄:Ce,Mn compositions. A comprehensive dosimetric evaluation was conducted, including reproducibility, linearity and signal fading. Among the studied samples, CaSO₄:Tm,Mn exhibited the most stable TL response, while CaSO₄:Dy,Mn showed the superior OSL signal stability. Overall, the results demonstrate that these newly developed CaSO₄-based RE,Mn composites possess excellent dosimetric characteristics, highlighting their strong potential as TL/OSL radiation detectors.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"192 ","pages":"Article 107624"},"PeriodicalIF":2.2,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146189396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optical response characterization of dyed-polymethyl methacrylate (PMMA) dosimeters under high-dose X-ray irradiation","authors":"Y.Q. Aguiar ,&nbsp;M. Avesani ,&nbsp;A. Raj Mandal ,&nbsp;X. Li ,&nbsp;V. Hutanu ,&nbsp;A. Morana ,&nbsp;R. García Alía ,&nbsp;S. Girard ,&nbsp;M. Ferrari","doi":"10.1016/j.radmeas.2026.107614","DOIUrl":"10.1016/j.radmeas.2026.107614","url":null,"abstract":"<div><div>This study assesses the suitability of commercial dyed polymethyl methacrylate (PMMA) dosimeters for high-dose radiation applications extending into the hundreds of kilograys. Three PMMA dosimeter types (Gammachrome YR+, Amber 3042, and Red 4034) were investigated using both online and post-irradiation optical transmission measurements in the visible spectral range. The objective was to evaluate their dose sensitivity beyond nominal operational limits and to characterize their optical response through multi-wavelength transmittance and radiation-induced attenuation (RIA) analyses. Dosimeters were exposed to X-rays at dose rates of 0.9 and 1.2 Gy[H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O]/s, covering doses from 0.1 Gy to 282 kGy. Monte Carlo simulations using the PHITS code were performed to model radiation transport and dose deposition in the different materials. The results demonstrate a clear, dose-dependent optical response of dyed PMMA, with wavelength-specific behavior indicative of color-center formation and evolution. Recovery measurements show that the RIA signal is highly stable over several hours at nominal wavelengths, with only minor relaxation observed in the near-infrared region, supporting the applicability of these dosimeters for both real-time and passive measurements. Comparisons with Radiophotoluminescent (RPL) FD-7 dosimeters reveal consistent trends, suggesting the potential for establishing a conversion between RPL and PMMA dose responses. Overall, the findings support the extension of dyed-PMMA dosimetry beyond current commercial limits and contribute to the development of robust dosimetry techniques for extreme radiation environments.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"192 ","pages":"Article 107614"},"PeriodicalIF":2.2,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Swift heavy ion and UV irradiation of natural cryolite (Na3AlF6)","authors":"Anna Szreter ,&nbsp;Adrian A. Finch ,&nbsp;Henrik Friis ,&nbsp;Christina Trautmann ,&nbsp;Frieder Koch ,&nbsp;Ina Schubert","doi":"10.1016/j.radmeas.2026.107606","DOIUrl":"10.1016/j.radmeas.2026.107606","url":null,"abstract":"<div><div>The successful application of fluorides in dosimetry and optics has encouraged study of the optical properties of doped cryolite and cryolite-structure materials. However, natural cryolite (Na₃AlF₆) has never been described in terms of its defect structure, crucial for optical applications. To address this knowledge gap, we irradiate cryolite with ²³⁸U ions and use excitation lifetime photoluminescence to constrain the defect structures formed. Untreated, high-energy ion and UV-irradiated samples are compared in terms of their emission spectra and luminescence lifetimes. Particle irradiation introduces an orange colour to originally black, purple and white cryolite. Untreated cryolite shows blue emissions at ∼2.86 and ∼2.60 eV (435 and 475 nm) and a green emission at 2.27 eV (545 nm). After uranium ion irradiation, the green luminescence intensity is enhanced compared to blue emissions. Subsequent ultraviolet irradiation causes ∼57 % reduction in the dark blue emission intensity and 40–70 % increase in green. All luminescence lifetimes are prolonged by particle irradiation, but stay in the nanosecond range. We infer that a vacancy-related defect is produced by particle and UV irradiation and responsible for the green luminescence. Another defect, presumably electronic, is removed by particle irradiation and UV. The ∼2.27 eV green luminescence centre is interpreted as an <em>F</em>-centre localised on a fluorine vacancy. The blue luminescence centres are interpreted as electron-hole pairs, localised at the AlF₆ octahedron normal lattice sites for ∼2.86 eV and octahedral defect sites for ∼2.60 eV. The experiment provides insight into natural defect formation processes in cryolite from the Ivittuut deposit in Southern Greenland.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"192 ","pages":"Article 107606"},"PeriodicalIF":2.2,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}