Radiation Measurements最新文献

{"title":"Experimental verification of dual-isotope imaging of 225Ac/213Bi using alpha imaging detector","authors":"Hyun Su Lee,&nbsp;Byungsoo Kim,&nbsp;Choong Mo Kang,&nbsp;Ilhan Lim,&nbsp;Kyochul Lee,&nbsp;JongGuk Kim","doi":"10.1016/j.radmeas.2025.107425","DOIUrl":"10.1016/j.radmeas.2025.107425","url":null,"abstract":"<div><div>Understanding the spatial distribution of alpha-emitting isotopes is important for advancing Targeted Alpha Therapy (TAT) research, particularly in identifying the biokinetics of alpha-labeled radiopharmaceuticals in pre-clinical animal experiments. However, challenges persist in alpha imaging, particularly in investigating the behavior of recoiled nuclides and long-lived daughter nuclides such as ²¹³Bi in the decay chain of ²²⁵Ac. In this study, we demonstrate dual-isotope imaging of ²²⁵Ac/²¹³Bi, through experimental validation. Building upon our previous Monte Carlo simulation study, the dual-isotope imaging is a method to spatially resolve ²²⁵Ac and ²¹³Bi using energy spectrum deconvolution technique. An alpha imaging detector, developed for TAT applications, comprises a GAGG(Ce) crystal, a silicon photomultiplier (SiPM), and a dedicated digital data acquisition system. The developed system features good energy resolution (3.9 % at 5 MeV alpha), allowing distinction of alpha particles according to their energy signatures while imaging, thereby facilitating the identification of the source isotope. The capability of the alpha imaging detector in spatially resolving ²²⁵Ac and ²¹³Bi was demonstrated on a source made of a thin-layer chromatography (TLC) where ²²⁵Ac-DOTATATE was separated. From the measurement of the TLC strip using the alpha imaging detector, the ²²⁵Ac/²¹³Bi ratio was estimated in distinct regions using two methods and compared: an analytic method using decay characteristics and the energy spectrum deconvolution method. The results demonstrated that using the dual-isotope imaging, amounts of ²²⁵Ac and ²¹³Bi in each region can be estimated as those estimated by the analytic method, even without repeated measurements. By distinguishing the origin of alpha particles from the image, we expect the dual-isotope imaging to provide a tool for better understanding the behavior of recoiled daughter nuclides from radiopharmaceuticals in animal bodies.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"183 ","pages":"Article 107425"},"PeriodicalIF":1.6,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143786043","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":"Improving the performance of pulse shape discrimination using feature selection preprocessing to scintillation counters","authors":"Qianqian Zhou ,&nbsp;Hongzhao Zhou ,&nbsp;Wenhui Li ,&nbsp;Jinglun Li ,&nbsp;Yuzhong Zhang ,&nbsp;Juncheng Liang ,&nbsp;Wuyun Xiao","doi":"10.1016/j.radmeas.2025.107423","DOIUrl":"10.1016/j.radmeas.2025.107423","url":null,"abstract":"<div><div>To meet the nuclear monitoring needs of neutron detection, a feature selection preprocessing was proposed to improve the performance of pulse shape discrimination (PSD) for scintillation counters. Feature selection was implemented by constructing a new pulse shape parameter (PSP) through feature weighting. These weights were assigned by leveraging the classification information, including the model difference and the standard deviations of each model, extracted from the reference pulse model (RPM) of typical neutron and gamma events. Two feature weighting methods were used, the model difference thresholding (MDT) for maximizing inter-class separability, and the model difference combined standard deviation (MDSD) to balance inter-class separability with intra-class compactness. To examine the method, the digitized signal waveforms from fast digitizer were analyzed, and the PSPs of PSD methods with and without feature selection were compared, including the charge comparison method (CCM) and the neutron gamma model analysis (NGMA). The figure of merit (FoM) was used to assess the discrimination performance, and the results indicated that this feature selection preprocessing can significantly improve the classification performance. Moreover, the optimization of classification performance is primarily contributed by inter-class separability in the low-energy region, whereas in the high-energy region, it comes from intra-class compactness.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"183 ","pages":"Article 107423"},"PeriodicalIF":1.6,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143726132","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":"Investigation of the gamma radiation resistance of MAPD-3NK and MPPC-S12572-10P SiPMs","authors":"F. Ahmadov ,&nbsp;A. Mammadli ,&nbsp;A. Sadygov ,&nbsp;D. Berikov ,&nbsp;G. Ahmadov ,&nbsp;M. Holik ,&nbsp;S. Nuruyev ,&nbsp;Z. Sadygov ,&nbsp;F. Mamadov","doi":"10.1016/j.radmeas.2025.107422","DOIUrl":"10.1016/j.radmeas.2025.107422","url":null,"abstract":"<div><div>In this paper, we investigate the physical properties of the MPPC-S12572-10P and MAPD-3NK silicon photomultipliers (SiPMs) operating in Geiger mode with both deep-buried pixels and surface pixel structure under the influence of gamma radiation with an average energy of 1.25 MeV. Both types of photodiodes were irradiated with doses of 10 kGy, 40 kGy and 100 kGy. Changes in the dark current, capacitance, photosignal amplitude and operating voltage of the irradiated photodiodes were studied.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"183 ","pages":"Article 107422"},"PeriodicalIF":1.6,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716141","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":"Investigating the characteristics of yellow stimulated luminescence from potassium feldspar","authors":"Gwynlyn Buchanan ,&nbsp;Frank Preusser ,&nbsp;Kathryn E. Fitzsimmons ,&nbsp;Tobias Lauer","doi":"10.1016/j.radmeas.2025.107421","DOIUrl":"10.1016/j.radmeas.2025.107421","url":null,"abstract":"<div><div>We investigate the characteristics of low-temperature yellow stimulated luminescence (YSL), to assess its utility for dating with infrared stimulated luminescence (IRSL) stimulated at 50 °C (IR₅₀), post-IR₅₀ yellow stimulated luminescence (pIR-YSL) and pIRIR₂₉₀. Altogether, eleven samples from a range of depositional environments and with a wide range of known ages were tested. Bleaching tests show that the pIR-YSL signal bleaches at a rate and extent that is similar to the IR₅₀ signal. Dose recovery tests on four of the young intermediate samples illustrate that the pIR-YSL signal can be both recovered and fully reset. Equivalent dose estimations of the modern samples indicate that the YSL₅₀ signal more consistently returns a result close to 0 Gy than the IR₅₀ signal in fluvial samples. The saturated samples show that the IR₅₀, IR-YSL and YSL₅₀ signals significantly underestimate relative to the pIRIR₂₉₀ signal and independent age control. Fading tests show that all three signals suffer from significant fading, with the largest fading effect on the YSL₅₀ signal, whereas the IR₅₀ and pIR YSL signals have similar fading rates. We note however, that the D_e values of the YSL₅₀ signal for the young intermediate samples are largely in agreement with independent age control, while the IR₅₀ signal underestimates and the pIRIR₂₉₀ results overestimate. We propose that low temperature YSL has the potential to be suitable for dating samples spanning from the last glacial maximum to the Holocene.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"183 ","pages":"Article 107421"},"PeriodicalIF":1.6,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143735269","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":"Application of TOPAS in dose calculations of low energy X-ray therapy machines","authors":"S. Ahmadi ,&nbsp;T. Monajemi","doi":"10.1016/j.radmeas.2025.107415","DOIUrl":"10.1016/j.radmeas.2025.107415","url":null,"abstract":"<div><div>TOPAS (TOol for PArticle Simulation) is a Monte Carlo tool initially designed for simulating proton therapy machines. This study aims to investigate TOPAS’s applicability and accuracy in simulating orthovoltage therapy machine. An Xstrahl 300 orthovoltage machine was simulated. Spectra, HVLs (Half Value Layers), PDDs (Percentage Depth Doses), dose profiles, and backscatter factors were calculated for 100, 180, and 300 kVp. In addition, 3D (Three-Dimensional) dose distributions on a cranial CT (Computed Tomography) were assessed for a 5 cm diameter field size in different treatment locations. Where applicable, comparisons against other measurements or calculations are presented. ”TrackLengthEstimator” method was employed to investigate the dose distributions in regions of interest. Spectra, except for fluorescent peaks, agree with SpekPy (An X-ray spectrum calculator) calculations. HVLs, PDDs, and dose profiles show agreement with clinical measurements. Backscatter factors for four field sizes (1, 3, 5, and 10 cm diameter) and all energies show agreement (difference &lt;2%) with published data. Visualization of dose distributions and DVHs (Dose Volume Histograms) on clinical CT sets are accessible functionalities. TOPAS is a robust Monte Carlo simulation tool for simulations of an orthovoltage treatment unit and could allow accessible visualization of 3D dose distributions in clinical plans.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"183 ","pages":"Article 107415"},"PeriodicalIF":1.6,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143642087","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":"Performance of CaF2:Mn dosimeters for determining entrance surface dose (ESD) in diagnostic radiology","authors":"Engin Aşlar ,&nbsp;Vural Emir Kafadar","doi":"10.1016/j.radmeas.2025.107419","DOIUrl":"10.1016/j.radmeas.2025.107419","url":null,"abstract":"<div><div>The performance of CaF₂:Mn (TLD-400) as dosimeters for dose measurements in diagnostic radiology including for entrance surface dose measurements (ESD) was investigated. Specifically, energy dependence, dose response, and repeatability properties of the thermoluminescence (TL) signal of the phosphor in diagnostic energy range were examined. The TL response of the dosemeter in the diagnostic energy range is about a factor of 10 more than its response to ¹³⁷Cs (662 keV). Irrespective of the energy of the X-rays used for CaF₂:Mn irradiation, TL response increased linearly with dose. Variation in TL responses of a chip of CaF₂:Mn reused seven times was within 5%. Entrance surface dose (ESD) measured with CaF₂:Mn are in agreement with those measured using TLD-100. The dosimeter's characteristics show that it can be used for both personnel and patients' dosimetry in diagnostic radiology.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"183 ","pages":"Article 107419"},"PeriodicalIF":1.6,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687792","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":"Impact of preparing temperature and soaking time on OSL of NaLi2PO4:Eu phosphor","authors":"Mo Zhou ,&nbsp;Kaiyong Tang ,&nbsp;Li Fu ,&nbsp;Siyuan Zhang ,&nbsp;Haijun Fan ,&nbsp;Yan Zeng","doi":"10.1016/j.radmeas.2025.107418","DOIUrl":"10.1016/j.radmeas.2025.107418","url":null,"abstract":"<div><div>NaLi₂PO₄:Eu was an optically stimulated luminescence (OSL) phosphor with good OSL stability but low OSL sensitivity. Many studies have indicated that the OSL properties of phosphors can be affected by modifications during the preparation process. The main focus of this research is to improve the NaLi₂PO₄:Eu OSL sensitivity by investigating the effects of the preparing temperature and soaking time on thermoluminescence (TL) and OSL properties. The samples synthesized at different preparation temperature and soaking time all exhibit pure phases. Differential Scanning Calorimetry indicates that the material undergoes an endothermic process between 850 °C and 1000 °C, and after 1000 °C, the material experiences an exothermic crystallization process. Our research find that the TL main peak and the initial OSL count are influenced by the preparing temperature in the material synthesis process, however, the stability of TL and OSL is not affected by the preparing temperature. Shortening the soaking time can increase the OSL stability of this material. Our measurement results suggest that the TL and OSL signals may originate from different traps. The process of heating at 1000 °C for 2 h has good OSL sensitivity and stability (3 % of fading). It has a linear dose response in the range of 0.1–5 Gy. Furthermore, the repeatability of this phosphor is excellent.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"183 ","pages":"Article 107418"},"PeriodicalIF":1.6,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629564","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":"Determination of the sensitive volume of a spherical ion chamber as a potential primary standard instrument for higher energy photon beams","authors":"Larry A. DeWerd ,&nbsp;Carlos E. de Almeida ,&nbsp;Olga M.O. de Araújo ,&nbsp;Karen Rex Pius Vincent ,&nbsp;Ahtesham Ullah Khan ,&nbsp;Leo Franco ,&nbsp;Ricardo Tadeu Lopes","doi":"10.1016/j.radmeas.2025.107416","DOIUrl":"10.1016/j.radmeas.2025.107416","url":null,"abstract":"<div><div>The sensitive volume of cylindrical or parallel plate ion chamber used as a primary standard for air kerma is typically determined using mechanical tools. This study presents an alternative methodology to determine the sensitive volume for a spherical chamber using a high-resolution imaging system, such as a microcomputed tomography unit (microCT). These determinations were done independently at both the University of Wisconsin (UW) and at State University of Rio de Janeiro (UERJ). The internal dimensions and the collection electrode of a spherical chamber (model Exradin® A3, Standard Imaging) were determined with a resolution better than the manufacturer's nominal volume value of 3.6 cm³ for the A3. In this study, at UERJ the measured sensitive volume of the A3 chamber was found to be 3.52 cm³ and at UW, after a correction for the electric field was made for the volume determination, it was found to be 3.54 cm³. The measured sensitive volume was compared against the volume calculated from an ADCL air kerma calibration with ⁶⁰Co at the UW. The agreement between these two methods was within 0.65%. Note that the chambers at UW and UERJ are two independent chambers and thus, the volume would not necessarily agree.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"183 ","pages":"Article 107416"},"PeriodicalIF":1.6,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628817","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":"The effect of light exposure on the thermoluminescence signal from calcitic opercula","authors":"D. Colarossi ,&nbsp;G.A.T. Duller ,&nbsp;H.M. Roberts ,&nbsp;R.J. Stirling ,&nbsp;K.E.H. Penkman","doi":"10.1016/j.radmeas.2025.107417","DOIUrl":"10.1016/j.radmeas.2025.107417","url":null,"abstract":"<div><div>Recent work has suggested that the thermoluminescence (TL) signal of opercula from the gastropod <em>Bithynia tentaculata</em> can be used to date the formation of calcite by the organism when it was alive. The two TL peaks of interest for dating are located at ∼250 °C (Peak 2) and ∼350 °C (Peak 3) when measured at a heating rate of 0.5 °C.s⁻¹. This paper assesses whether these peaks are altered by exposure to visible light, as this is important for how samples are collected in the field, and handled in the laboratory prior to measurement. Neither peak shows systematic change for exposures in a solar simulator of less than 24 h in duration. For longer exposures in the solar simulator the intensity of Peak 2 increases, possibly due to phototransfer. In contrast, the TL signal from Peak 3 is not affected by light exposure in the solar simulator for periods of up to 60 h, or by exposure to natural daylight with the UV-component removed for periods of up to ∼26 d. One experiment which exposed an operculum to natural daylight for ∼5.5 months led to a reduction in the TL signal from Peak 3 by 16 %, but such long exposures are unlikely in sampling and sample preparation. The lack of impact of daylight exposure on Peak 3 indicates that opercula-bearing samples can be collected and processed in normal daylight conditions, and that museum specimens are suitable for TL dating provided an associated sediment sample is available for dose rate calculations. However, as a precaution it is still recommended that light exposure is minimised where possible.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"183 ","pages":"Article 107417"},"PeriodicalIF":1.6,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143611745","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 a compact detector for measurement of alpha contamination in piping","authors":"Yuki Morishita ,&nbsp;Léo Peschet ,&nbsp;Tsutomu Yamada ,&nbsp;Takamasa Nakasone ,&nbsp;Marina Kanno ,&nbsp;Miyuki Sasaki ,&nbsp;Yukihisa Sanada ,&nbsp;Tatsuo Torii","doi":"10.1016/j.radmeas.2025.107414","DOIUrl":"10.1016/j.radmeas.2025.107414","url":null,"abstract":"<div><div>In the decommissioning nuclear facilities, it is crucial to inspect piping for contamination to prevent worker exposure to alpha-emitting nuclides. Traditional methods using gamma rays and neutrons are inadequate for detecting small amounts of alpha nuclides due to the short range (approximately 4 cm) of alpha particles in air. To address this, we developed a compact detector capable of distinguishing between alpha particles for direct measurement within pipes. This detector, comprising a ZnS(Ag) scintillator for alpha particles and a plastic scintillator for beta particles, was coupled to a small photomultiplier tube. The system demonstrated high accuracy in differentiating between alpha and beta radiation through pulse shape discrimination (PSD). Monte Carlo simulations and empirical measurements confirmed the detector's effectiveness, achieving a 51.3% detection efficiency for alpha particles with negligible sensitivity to beta and gamma radiation. This innovation presents a significant advancement for direct alpha contamination measurement in environments with high beta and gamma backgrounds, such as the Fukushima Daiichi Nuclear Power Plant decommissioning site.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"183 ","pages":"Article 107414"},"PeriodicalIF":1.6,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579709","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}