Radiation Measurements最新文献

{"title":"Radiochromic film as a reference detector for field output factor determination in small photon field dosimetry","authors":"O.A. García-Garduño , M.R. Mirón-Lozada , J.M. Lárraga-Gutiérrez","doi":"10.1016/j.radmeas.2025.107413","DOIUrl":"10.1016/j.radmeas.2025.107413","url":null,"abstract":"","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"183 ","pages":"Article 107413"},"PeriodicalIF":1.6,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488816","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":"Calibration of 90Sr + 90Y planar sources using thermoluminescent dosimeters, radiochromic film, a PMMA phantom and Monte Carlo simulation","authors":"Daniel Litvac,&nbsp;Linda V.E. Caldas","doi":"10.1016/j.radmeas.2025.107403","DOIUrl":"10.1016/j.radmeas.2025.107403","url":null,"abstract":"<div><div>In some parts of Brazil, ⁹⁰Sr + ⁹⁰Y clinical applicators are still in use for dermatological and ophthalmic treatments, even with new technologies worldwide, because they are of lower cost and easier use. Calibration and periodic recalibration of these applicators to verify the absorbed dose rate is essential to ensure accuracy in clinical treatments. This work focused on an alternative calibration method for ⁹⁰Sr + ⁹⁰Y sources, utilizing thermoluminescent dosimeters, radiochromic films, and Monte Carlo simulation, following international recommendations. Regarding radiation doses, the thermoluminescent response of μLiF pellets and the response of radiochromic films were evaluated to determine reproducibility, linearity of response, and their dose-response curves. Additionally, radiochromic films were used to determine the dose rate distribution across the areas of the clinical applicators, and the μLiF dosimeters were used as a comparative measure in determining the axial central dose rate of clinical applicators. A PMMA phantom was developed and utilized to perform the calibrations. Monte Carlo simulation was essential for replicating the radioactive properties and correction factors for radiation and deposited doses in two media and at different distances from these sources. This work presents a practical and cost-effective method for calibrating planar ⁹⁰Sr + ⁹⁰Y radioactive sources; it was developed to serve locations that lack state-of-the-art technological resources, and was validated for effectiveness and broad applicability. The developed technique allows for long-distance calibration using dosimetric materials, provided they are properly handled and shielded.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"183 ","pages":"Article 107403"},"PeriodicalIF":1.6,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143527131","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":"Applicability of a narrow glass tube for optical dosimetry with boron-added liquid scintillator using a digital camera in boron neutron capture therapy","authors":"Hideya Maeda ,&nbsp;Akihiro Nohtomi ,&nbsp;Aoto Moriguchi ,&nbsp;Naonori Hu ,&nbsp;Kazuhiko Akita ,&nbsp;Koji Ono","doi":"10.1016/j.radmeas.2025.107411","DOIUrl":"10.1016/j.radmeas.2025.107411","url":null,"abstract":"","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"183 ","pages":"Article 107411"},"PeriodicalIF":1.6,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A simplified γ-γ coincidence method to measure the activity of radionuclide","authors":"Qiankun Shao ,&nbsp;Qingjun Zhu ,&nbsp;Jia Li ,&nbsp;Songlin Liu","doi":"10.1016/j.radmeas.2025.107412","DOIUrl":"10.1016/j.radmeas.2025.107412","url":null,"abstract":"<div><div>A simplified γ-γ coincidence method for activity measurement when a sample containing multiple γ-ray emitters is proposed. This method can be applied when a γ-γ cascade process occurs in the radionuclide of low detection efficiency. And the activity can be calculated from the full-energy peak count rate of the cascade particles in each detector and the corresponding full-energy-full-energy coincidence count rate. To verify this simplified method, it was compared with numerous γ-γ coincidence methods using Monte Carlo simulation. Limitations and applicability of these methods are discussed. In addition, to validate this method in real environments, a digital coincidence measurement system using two NaI(Tl) detectors was developed. The measurements were performed on a standardized ⁶⁰Co source and a standardized ⁶⁰Co source in the presence of a¹³⁷Cs standardized source.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"183 ","pages":"Article 107412"},"PeriodicalIF":1.6,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552637","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":"X-ray-induced scintillation properties of CsI:Ho single crystals","authors":"Shunta Takase,&nbsp;Keiichiro Miyazaki,&nbsp;Daisuke Nakauchi,&nbsp;Takumi Kato,&nbsp;Noriaki Kawaguchi,&nbsp;Takayuki Yanagida","doi":"10.1016/j.radmeas.2025.107402","DOIUrl":"10.1016/j.radmeas.2025.107402","url":null,"abstract":"<div><div>CsI:Ho single crystals were fabricated, and their scintillation properties were investigated. Under irradiation with X-rays, two broad bands due to self-trapped excitons of CsI were observed at 310 and 430 nm. Moreover, CsI:Ho showed several emission peaks at 550, 640, 990, 1200, 1320, and 1490 nm due to 4f-4f transitions of Ho³⁺. The obtained scintillation decay time constants were 1.65–1.74 ms. From dose rate response functions, the 0.05% CsI:Ho showed linearity between 10 and 1000 mGy/h, and the low detection limit was 7 mGy/h.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"183 ","pages":"Article 107402"},"PeriodicalIF":1.6,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474937","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":"Feasibility study of multiplexing analog signals from SiPMs for a single layer monolithic PET detector design","authors":"Shiv K. Subedi ,&nbsp;Simon R. Cherry ,&nbsp;Yi Qiang ,&nbsp;Peng Peng","doi":"10.1016/j.radmeas.2025.107399","DOIUrl":"10.1016/j.radmeas.2025.107399","url":null,"abstract":"<div><div>Semi monolithic detector designs with a series of stacked thin monolithic scintillator plates and side readout are an attractive approach for potentially achieving very high performance in a positron emission tomography (PET) scanner. In this work, a simulation study of a single layer monolithic detector module was performed with side read out of scintillation light using GATEv8.2. In this design, a single layer LSO crystal was used with dimensions <span><math><mrow><mn>40</mn><mspace></mspace><mi>mm</mi><mo>×</mo><mn>40</mn><mspace></mspace><mi>mm</mi><mo>×</mo><mn>4</mn><mspace></mspace><mi>mm</mi></mrow></math></span>, with 0.60 mm thickness of the ESR (enhanced specular reflector) films covering the crystal's top and bottom surfaces. The photons generated in the scintillation process induced by the gamma ray hitting the crystal were detected by four 1 × 8 SiPM (silicon photomultiplier) arrays placed along the four sides of the crystal. The scintillation light distribution detected by all the 32 SiPMs surrounding the crystal layer was then used to extract the gamma-crystal interaction location based on machine learning analysis. In this work, the spatial resolution of the detector module was explored when analog signals from each of the 32 SiPMs were summed to 28, 24, 20, 16, 12, 8, and 4 total outputs. This study showed that good spatial resolution can be achieved even when the number of read out channels is decreased by multiplexing, which can reduce the overall detector manufacturing cost.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"182 ","pages":"Article 107399"},"PeriodicalIF":1.6,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421500","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":"Enhanced neutron-gamma discrimination with fast signal output from SiPM arrays via deep neural network optimization","authors":"Yi Guo ,&nbsp;Zhiyong Wei ,&nbsp;Meihua Fang ,&nbsp;Yulian Zhang ,&nbsp;Xinyi Cai ,&nbsp;Mengmeng Wang ,&nbsp;Yipan Guo ,&nbsp;Chuanyuan Fu ,&nbsp;Peng Li ,&nbsp;Ming Zhang ,&nbsp;Jiafeng Li ,&nbsp;Ziqi Wu","doi":"10.1016/j.radmeas.2025.107400","DOIUrl":"10.1016/j.radmeas.2025.107400","url":null,"abstract":"<div><div>High count rate neutron measurements require fast signal outputs and effective neutron-gamma discrimination techniques, yet the wide pulse widths generated by silicon photo-multipliers (SiPM) arrays often limit their efficiency in such settings. In prior work, we developed a compensation network (CN) to reduce pulse width and overshoot in SiPM fast outputs, improving pulse shape discrimination (PSD). However, further enhancement was needed to achieve optimal neutron-gamma discrimination. Conventional methods like charge comparison method (CCM) and frequency gradient analysis (FGA) typically analyze either time-domain or frequency-domain features independently. In this study, we employ a deep neural network (DNN) that integrates both frequency and time-domain features from ultra-fast pulse signals to improve discrimination accuracy. We optimized DNN model inputs through a systematic variable selection strategy that included separation ranking, correlation analysis, and recursive feature elimination (RFE), reducing the input set from 73 to 27 variables for a balance of simplicity and discriminative power. The neutron-gamma discrimination was then quantified with an equivalent figure of merit (FOM). Testing with the ²⁵²Cf source demonstrated the superior performance of the DNN-based approach, achieving an FOM of 0.96 (98.8% discrimination probability) compared to 0.73 (95.7%) for CCM and 0.63 (93.0%) for FGA. These findings underscore the potential of enhanced ultra-fast signal output systems for nuclear detection in high-count-rate applications.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"182 ","pages":"Article 107400"},"PeriodicalIF":1.6,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143436721","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":"An empirical study on the variability of luminescence ages for coeval sediment samples","authors":"D. Constantin ,&nbsp;R. Begy ,&nbsp;D.A.G.J. Vandenberghe ,&nbsp;D. Veres ,&nbsp;A. Timar-Gabor","doi":"10.1016/j.radmeas.2025.107401","DOIUrl":"10.1016/j.radmeas.2025.107401","url":null,"abstract":"<div><div>Optically stimulated luminescence (OSL) dating is a widely used numerical-age technique in Quaternary research. OSL age datasets at high vertical resolution are increasingly generated in order to quantify rates of processes or to identify gaps in the sediment record. However, incorporation of luminescence ages in age-depth models or age comparisons is not straightforward due to the variety and complex combination of uncertainties associated with luminescence dating. Moreover, previous studies reported on a variability in age results for coeval loess samples that is significantly larger than expected and remains to be understood.</div><div>In this study we aim to provide the first empirical assessment of the variability in the OSL ages in coeval sediment samples. Multiple samples have been collected at high horizontal resolution, from loess and an aeolian sand layers that bracket Campanian Ignimbrite/Y-5 tephra (⁴⁰Ar/³⁹Ar dated to 39.9 ± 0.1 ka), in southern Romania, southeastern Europe. All individual 63–90 μm quartz OSL ages are stratigraphically consistent with this independent age control within 1 σ or 2 σ uncertainty. There is a 1.7 % scatter in the individual ages in the sand layer and 4.6 % in the loess layer.</div><div>The various sources of uncertainty are detailed and we observe that the random sources of uncertainty have a limited contribution to the total uncertainty of the age and the systematic sources of uncertainty dominate. Weighted average ages of 46 ka and 39 ka are calculated for the sediment layers below and above the tephra, respectively. The overall random uncertainty of the weighted OSL ages (1.1 % sands, 1.6 % loess) is similar to the observed random uncertainty among individual OSL ages (0.8 % sands, 0.9 % loess) which indicates that the sources of variability in the OSL ages are properly accounted.</div><div>By averaging ages on multiple coeval samples, the precision (random uncertainty) of the age of the sedimentary context was improved with up to 1.9 % and 3.8 % in the sand and loess layers, respectively, compared to that on individual ages. Such an increase in precision of the age may lead to improvements in the precision of relative age-frameworks based on luminescence dating. However, averaging ages of coeval samples has a small effect on the overall uncertainty associated to the average weighted age, owing to a less than 10 % fractional contribution of overall random uncertainties to the total age uncertainty budget. Our empirical results show that for the samples investigated here it is not possible to obtain a luminescence age with an overall relative uncertainty of less than 6 %.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"182 ","pages":"Article 107401"},"PeriodicalIF":1.6,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Review of solid-state detectors for out-of-field dosimetry and microdosimetry in particle therapy","authors":"Linh Tran ,&nbsp;Cristina Oancea ,&nbsp;Satoshi Kodaira ,&nbsp;David Bolst ,&nbsp;James Vohradsky ,&nbsp;Carlos Granja ,&nbsp;Jan Jakubek ,&nbsp;Jaroslav Šolc ,&nbsp;Elisabeth Bodenstein ,&nbsp;Sebastian Gantz ,&nbsp;Jörg Pawelke ,&nbsp;Lukas Marek ,&nbsp;Anatoly Rosenfeld","doi":"10.1016/j.radmeas.2025.107386","DOIUrl":"10.1016/j.radmeas.2025.107386","url":null,"abstract":"<div><div>Fragments and neutrons produced by inelastic reactions in particle therapy can make a significant contribution to the Relative Biological Effectiveness (RBE) and as a consequence the biologically weighted-dose in the distal part of the Spread-out Bragg Peak (SOBP); this also make changes to the radiation quality and dose equivalent in surrounding organs near the target tumour. These mixed radiation fields of secondary fragments and neutrons are difficult to characterise which is why this paper reviews some solid state radiation detectors that can measure the radiation field produced out of primary field in particle therapy, and also assess the radiation quality and dose equivalent to normal organs located near the target volume. These detectors include active types such as the silicon on insulator (SOI) microdosimeter, the monolithic <em>Δ</em>E-E telescope, the pixel detectors TimePix3, and passive detectors such as CR-39 plastic charged particle track detector, and the fluorescent nuclear track detector (FNTD).</div><div>This paper also reports on the microdosimetric measurements obtained with silicon-based microdosimeters, both laterally and downstream of the target volume, for proton and carbon ion beams. It also details the measurements taken by the TimePix3 detector, including a customised, miniaturized version with enhanced resolving power, for characterizing secondary radiation in proton therapy through single-particle tracking. The CR-39 and FNTD passive linear energy transfer (LET) detectors are also reviewed and the advantages and disadvantages of each type of detector are discussed.</div><div>The SOI microdosimeter and <em>Δ</em>E-E telescope are suitable for characterising the typical mixed radiation field for out-of-field in particle therapy. An SOI microdosimeter can provide dose equivalent values to evaluate risk to normal organs, while the <em>Δ</em>E-E telescope can operate as a microdosimeter and distinguish the type of particles in the secondary radiation field. The TimePix3 chip can provide mixed field decomposition, particle flux, dose rate, and LET spectra while the CR-39 plastic detector could measure the LET spectra, absorbed dose, and dose equivalent from secondary particles of Carbon ion beam via nuclear targeted fragmentation reactions.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"182 ","pages":"Article 107386"},"PeriodicalIF":1.6,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of an algorithm for automated estimation of fetal head dose in pelvimetric CT scans based on geometrical considerations","authors":"Hamza Sekkat ,&nbsp;Abdellah Khallouqi ,&nbsp;Omar El rhazouani ,&nbsp;Youssef Madkouri ,&nbsp;Wiam El Atifi ,&nbsp;Abdellah Halimi","doi":"10.1016/j.radmeas.2025.107387","DOIUrl":"10.1016/j.radmeas.2025.107387","url":null,"abstract":"<div><div>This study addresses radiation safety for fetal exposure during pelvimetry Computed Tomography (CT) scans in pregnant women, specifically in the Moroccan context. While previous studies in Morocco have utilized Monte Carlo simulations or established formalisms for effective dose estimations, none have computed a size-adjusted dose estimates for the fetal head using an automated method. The goal of this research was to enhance fetal radiation safety by developing a Python-based script for automating fetal head contouring and estimating a Size-Adjusted Fetal Head Dose (SAFHD). The automation process addresses challenges posed by the presence of other bone structures in the pelvis, therefore, a custom Python script was developed for image preprocessing, including normalization, region of interest (ROI) selection, binary image creation, morphological processing, mask creation, and region labeling. These steps ensured detection and isolation of the fetal head region. The SAFHD method adjusts the dose estimation for the fetal head based on its unique anatomical characteristics, adapting the conventional SSDE framework. This retrospective study used datasets comprising axial CT images from 136 pregnant women, all scanned using a standardized 80-detector CT scanner. The process of estimating SAFHD included several key steps: (1) calculating the pelvis SSDE using the AAPM Report 220 method for adult body CT scans, (2) introducing a correction factor (k) to adjust the pelvis SSDE to fetal head dose from previous findings, (3) performing automated fetal head contouring to extract the lateral (LAT) and anteroposterior (AP) dimensions of the fetal head, (4) calculating the water-equivalent diameter (Dw) from LAT and AP values and (5) using a size-specific conversion factor derived from interpolated pediatric head data in AAPM reports 220 and 293 to complete the SAFHD estimation. The automated method showed strong correlation with manual measurements taken by ten observers, with correlation coefficients of 0.96 for LAT and 0.94 for AP dimensions. The intraobserver agreement for Dw measurements was highly consistent, with ICC values ranging from 0.960 to 0.999. The final SAFHD values, derived using the correction factor and size conversion based on fetal head dimensions, correlated strongly (0.98) with manual estimations. By incorporating both maternal pelvis dose and specific fetal head dimensions, the SAFHD estimation offers a promising tool for clinicians to accurately estimate fetal radiation doses and verify dose limits, minimizing radiation-related risks to the fetus.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"182 ","pages":"Article 107387"},"PeriodicalIF":1.6,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395531","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}