Radiation Measurements最新文献

{"title":"Modelling the X-ray thermoluminescent response of CaSO4:Dy for dosimetry in diagnostic radiology by EGSnrc Monte Carlo method","authors":"Bui Ngoc Huy","doi":"10.1016/j.radmeas.2025.107487","DOIUrl":"10.1016/j.radmeas.2025.107487","url":null,"abstract":"<div><div>In this study, the EGSnrc Monte Carlo (MC) code was used to evaluate the energy response of CaSO₄:Dy thermoluminescence dosimeters (TLD 900). CaSO₄:Dy (0.15 wt% Dy) dosimeters in powder form were studied to evaluate their energy response to X-ray and gamma radiations at room temperature on the PMMA phantom. The photon energy response, the correction factor, the response of elements C1 and C2, the <em>r12</em> ratio, and the dose algorithm in terms <span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span>(10) were developed, leveraging both simulation results and physical measurements. The energy and dose algorithm’s estimations were compared against experimental data to validate its accuracy and identify potential discrepancies. A dose algorithm for <span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span>(10) estimation within an accuracy of 20% was developed from the <em>r12</em> ratio of elements under different filters using photon energy ranging from diagnostic X-ray. In addition, the simulation results agree well with the physical measurements, validating that the MC simulation method is well-suited for describing the interactions of particles and materials with complex geometries under different irradiation conditions.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"187 ","pages":"Article 107487"},"PeriodicalIF":2.2,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144721227","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":"Absolute dosimetry on dynamically scanned 4T wiggler beams for synchrotron radiotherapy using graphite calorimetry","authors":"P.D. Harty ,&nbsp;N. Vandenberg ,&nbsp;D.J. Butler ,&nbsp;T.E. Bailey ,&nbsp;M. Cameron ,&nbsp;A.W. Stevenson","doi":"10.1016/j.radmeas.2025.107498","DOIUrl":"10.1016/j.radmeas.2025.107498","url":null,"abstract":"<div><div>Graphite calorimetry has previously been established as a primary method for determining the absorbed dose delivered to a dynamically scanned sample in the Imaging and Medical Beamline (IMBL) on the Australian Synchrotron. The beamline has since increased the maximum field at which the wiggler can operate from 3T to 4T, resulting in changed spectral output and significantly higher dose rates (up to around 6000 Gy/s). We use the graphite calorimeter and calculations to determine the absorbed dose to water delivered by these new beams and compare the results with measurements from a PTW 31014 Pinpoint chamber and two PTW 31022 3D Pinpoint chambers, which were all calibrated in conventional x-ray beams. The results are in good agreement with the conventional x-ray calibrations for a range of filtrations. We conclude that the current dosimetry protocol with pinpoint ionization chambers is appropriate at the new wiggler field.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"187 ","pages":"Article 107498"},"PeriodicalIF":2.2,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144721226","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":"Detection efficiency goal optimization of energy-selective gamma-ray imaging system by magnification imaging","authors":"Tianxing Da ,&nbsp;Changqing Zhang ,&nbsp;Jiming Ma ,&nbsp;Baojie Nie ,&nbsp;Liang Sheng ,&nbsp;Bochen Wang ,&nbsp;Baojun Duan ,&nbsp;Yang Li ,&nbsp;Dongwei Hei ,&nbsp;Dezhong Wang","doi":"10.1016/j.radmeas.2025.107500","DOIUrl":"10.1016/j.radmeas.2025.107500","url":null,"abstract":"<div><div>In the study of Inertial Confinement Fusion (ICF), energy-selective imaging of 4.44 MeV gamma rays is critical for assessing the volume and symmetry of the ablator. However, existing energy-selective gamma-ray imaging systems suffer from low detection efficiency. This paper proposes a goal optimized detection system for energy-selective gamma-ray imaging, which improves detection efficiency by optimizing the conversion target and electron collection angle to match the target detection efficiency. Additionally, to preserve spatial resolution, a magnification imaging technique is employed to minimize high-order aberrations. Simulation of the entire system using Monte Carlo methods demonstrates that the system achieves a detection efficiency of 9.4 × 10⁻⁴ and an energy resolution of 0.54 MeV for 4.44 MeV gamma-ray energy. The system exhibits a spatial resolution of around 1 mm in the horizontal (x) direction and 2.5 mm in the vertical (y) direction across a 60 × 60 mm² field of view. The goal optimization method of energy-selective gamma-ray imaging system based on magnification imaging further proves the application prospect of energy-selective gamma-ray imaging technology in ICF experiment.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"187 ","pages":"Article 107500"},"PeriodicalIF":2.2,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144739536","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":"Luminescence and scintillation characteristics of Pr-doped Lu2.5Y0.5(Al2.5Ga2.5)O12 single crystals","authors":"Prapon Lertloypanyachai ,&nbsp;Prom Kantuptim ,&nbsp;Chatchawan Kantala ,&nbsp;Toshiaki Kunikata ,&nbsp;Weerapong Chewpraditkul ,&nbsp;Takumi Kato ,&nbsp;Daisuke Nakauchi ,&nbsp;Noriaki Kawaguchi ,&nbsp;Takayuki Yanagida","doi":"10.1016/j.radmeas.2025.107499","DOIUrl":"10.1016/j.radmeas.2025.107499","url":null,"abstract":"<div><div>In this work, Lu_2.5Y_0.5(Al_2.5Ga_2.5)O₁₂ (LuYAGG) garnet single crystals doped with Pr³⁺ at concentrations of 0.5, 1, 2, and 4 mol% were synthesized using the floating-zone method with a pulling rate of 4 mm/h. These crystals displayed high transmittance in the visible range (85 %–95 %), and Pr³⁺ absorption features were identified near 278 nm, corresponding to the 4f-5d₁ transition. Photoluminescence (PL) emissions were observed between 300 and 430 nm (5d₁-4f transition) and 430–680 nm (4f-4f transition), as illustrated by PL contour mapping. Under X-ray excitation, radioluminescence (RL) spectra showed broad emissions in the 290–450 nm and 450–680 nm ranges, consistent with 5d₁-4f and 4f-4f transitions, respectively. Among all tested compositions, the sample doped with 2 mol% Pr³⁺ demonstrated the best scintillation light yield, approximately 20,000 photons/MeV when excited by 662 keV γ-rays, and achieved an energy resolution of 24.6 %. The PL decay time constants for all samples were within the range of several tens of nanoseconds.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"187 ","pages":"Article 107499"},"PeriodicalIF":2.2,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144780888","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":"Identifying the origins of possible nonlinear scintillator response under ultra-high dose rate electron beams","authors":"Daline Tho ,&nbsp;Sam Beddar","doi":"10.1016/j.radmeas.2025.107494","DOIUrl":"10.1016/j.radmeas.2025.107494","url":null,"abstract":"<div><h3>Purpose/objective</h3><div>Previous studies of the Exradin-W2 (Standard Imaging, Middleton, WI, USA) organic scintillator under ultra-high dose rate (UHDR) electron beams, have shown signs of saturation at high pulse repetition frequencies (PRF) and high doses per pulse (DPP). This study investigated the hypothesis that the saturation observed in the W2 is due to limitations of the electrometer rather than the scintillator itself.</div></div><div><h3>Material/methods</h3><div>We conducted a series of measurements to assess the performance of a 1 × 3 mm W2 detector and a 1 × 2 mm BCF-12 scintillator under 9 MeV electron beams. The experiment was carried out using a spectrometer capable of handling a wide range of signal intensities. The area under the curve was computed for each spectrum and used to compare across all measurements. To investigate the behavior of the detector to variations in PRF, we adjusted the PRF values from 10 Hz to 120 Hz. The linearity to integrated dose was validated by varying the number of pulses per acquisition. Additionally, we tested the linearity of the detector's response to DPP by changing the surface-to-source distance up to a DPP of 5.4 Gy. Finally, the W2 was connected to a long clear fiber extension and was used with the MAX SD electrometer under the same beam parameters as the previous measurements.</div></div><div><h3>Results</h3><div>The signal sensitivity variation for BCF-12 remained under 6 % for all pulse width (PW) values tested across all PRFs, whereas for the W2, the maximum decrease in signal sensitivity (3 %) was for a PW of 2 μs at 60 Hz. The linearity of the detector's response was maintained across all pulse numbers tested. Both detectors' responses remained linear with respect to both integrated dose and DPP. The W2 with the clear fiber extension showed a decrease in signal as the PRF increased.</div></div><div><h3>Conclusion</h3><div>These findings suggest that the previously observed nonlinear effects are likely attributable to limitations of the electrometer, which was not designed for use with UHDR beams, rather than intrinsic properties of the W2 scintillator.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"187 ","pages":"Article 107494"},"PeriodicalIF":2.2,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144771347","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 pile-up and summation effects on the calibration curves of boron concentration measurement in PGNAA","authors":"M.H. Choopan Dastjerdi ,&nbsp;M. Jafari ,&nbsp;J. Mokhtari ,&nbsp;H. Jafari","doi":"10.1016/j.radmeas.2025.107495","DOIUrl":"10.1016/j.radmeas.2025.107495","url":null,"abstract":"<div><div>In the previous research, the self-shielding effect in boron concentration measurement using PGNAA method was corrected by an internal standard material. After correction of the self-shielding, the calibration curve still has some curvature that was not seen in the calibration curve related to simulations spectra. The basic difference between the simulations and experiments was that the actual detection process in an HPGe detector and its related electronics were not simulated. The reason of this difference is the pile-up and summation effects on the spectra during the experiments. In this study, the pile-up and summation effects have been investigated at the different peaks of the spectra. Two methods have been proposed to correct these effects. In the first method, a suitable peak from the spectrum of the internal standard material has been selected and the self-shielding effect has been corrected and in the second method, the mass of the standard samples and the spectrometry time have been reduced and increased, respectively. The results of these methods have been evaluated by different experiments. Results shows that in the correction of the self-shielding effect, the 788 keV + 786 keV peak of chlorine has the best performance. Among the calibration curves plotted with different chlorine peaks, the curve plotted using 788 keV + 786 keV peak had the best linearity. The R-square of this curve was 0.99891. Also, it was found that reducing the mass of the standard samples used to obtain the calibration curve, reduces the nonlinearity caused by the pile-up and summation effects on the calibration curve. By reducing the volume of standard samples used to obtain the calibration curve from 10 ml to 4 ml, the R-squared of the calibration curve obtained in the first method increased from 0.99891 to 0.99904.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"187 ","pages":"Article 107495"},"PeriodicalIF":1.6,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144696908","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":"Radiation damage of the W2 plastic scintillator under ultra-high dose rate FLASH electron beam","authors":"Daline Tho ,&nbsp;Kevin Liu ,&nbsp;Shannon Holmes ,&nbsp;Emil Schüler ,&nbsp;Sam Beddar","doi":"10.1016/j.radmeas.2025.107492","DOIUrl":"10.1016/j.radmeas.2025.107492","url":null,"abstract":"<div><h3>Objectives</h3><div>This project aimed to detail the response of the Standard Imaging Exradin-W2 plastic scintillator detector (PSD) as a function of accumulated dose under ultra-high dose rate (UHDR) electron beams.</div></div><div><h3>Approach</h3><div>This experiment was performed with 9 PSDs and 3 clear optical guide fibers to distinguish between the radiation damage response of the optical guide and the response of the scintillator. The PSDs and the transmitting optical fibers were exposed to a 9 MeV electron beam using a Mobetron electron linear accelerator (IntraOp) at a dose per pulse (DPP) of 3 and 8 Gy, reaching a total cumulative dose of 12 kGy. The PSD's response to both conventional dose rate (CDR) and UHDR irradiation was measured in triplicate prior to any radiation exposure. Conventional and UHDR irradiations were repeated at various increasing doses to assess changes in the sensitivity of the detector. The high dose irradiations were always performed under UHDR. After 2 months with no radiation exposure, the detectors and fibers underwent irradiation regimens identical to the initial ones to quantify their recovery.</div></div><div><h3>Main results</h3><div>The Exradin-W2 PSD blue channel exhibited an average sensitivity loss of (2.0 ± 0.2) %/kGy under UHDR and similar loss was found for CDR. The optical fiber showed a mean response decrease of (1.2 ± 0.1) %/kGy for UHDR. When irradiating the optical fiber of three W2s, the average sensitivity loss in the blue signal was (6.4 ± 0.2) %/kGy for CDR and (6.3 ± 0.2) %/kGy for UHDR. Mean response recovery of 10 ± 3 % was observed for detectors exposed to conventional beams and (18 ± 4) % for UHDR for the blue channel. Overall, the W2 PSD's response (blue and green channels) remained within 3 % of the initial baseline measurement when the cumulative dose was under 2 kGy.</div></div><div><h3>Significance</h3><div>Our results indicate that the W2 PSD exhibited greater sensitivity loss under UHDR than conventional beams found in prior studies. The results suggest that varying DPP does not change the sensitivity loss of the W2. We noted a decrease of the blue channel relative to the green channel in the optical fiber response, which adds to the overall radiation damage to the PSD. Therefore, users should track cumulative dose and recalibrate after each 2 kGy of exposure.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"187 ","pages":"Article 107492"},"PeriodicalIF":1.6,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144686856","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 influence of beta-irradiation dose and stimulation temperature on luminescence optically stimulated from rose quartz using linear-modulation","authors":"K.A. Opoku ,&nbsp;N.M. Trindade ,&nbsp;M.L. Chithambo","doi":"10.1016/j.radmeas.2025.107493","DOIUrl":"10.1016/j.radmeas.2025.107493","url":null,"abstract":"<div><div>We present linearly modulated optically stimulated luminescence (LM-OSL) of rose quartz. The luminescence was stimulated using 470 nm blue light. The time-dependent plot of the luminescence intensity shows two distinct peaks. Analysis of this LM-OSL curve by deconvolution shows that it consists of at least five components. A number of factors related to these components have been considered. In particular, the effect of beta dose on kinetic parameters such as the optical stimulation probability and the photoionisation cross-section are reported. The thermoluminescence (TL) glow curve measured at 1 °C/s after irradiation to 10 Gy shows a high intensity peak at 76 °C and weaker-intensity ones at 118, 192, 300 and 412 °C. The primary peak at 76 °C is affected by thermal quenching. The value of the activation energy for thermal quenching as evaluated using LM-OSL and TL are consistent suggesting a common recombination center for the LM-OSL and TL of the primary peak.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"187 ","pages":"Article 107493"},"PeriodicalIF":1.6,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144672191","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":"Isolated radiation damage created along un-etchable tracks in PADC consists of two hydroxyl groups","authors":"Tomoya Yamauchi ,&nbsp;Reo Yamada ,&nbsp;Atsushi Kimoto ,&nbsp;Hayato Seiichi ,&nbsp;Shunto Sadamitsu ,&nbsp;Daisuke Kohinata ,&nbsp;Masato Kanasaki ,&nbsp;Ichiro Sasaki ,&nbsp;Shigeki Watanabe ,&nbsp;Noriko S. Ishioka ,&nbsp;Nobumasa Miyawaki","doi":"10.1016/j.radmeas.2025.107491","DOIUrl":"10.1016/j.radmeas.2025.107491","url":null,"abstract":"<div><div>The objective of the present work is to clarify the damage structure along un-etchable tracks in PADC, by determining the damage density of ether as well as the formation density of hydroxyl group along them. Both the damage density and the formation density have been evaluated by means of FT-IR spectrometry on PADC films before and after the exposures to 30 MeV and 65 MeV proton beams with various fluence. The ratio of the damage density of ether to the formation density of hydroxyl group was about 1:2, which was almost identical to those for protons and He ions with energies of below 6 MeV/u. Futhermore, the ratio was hardly changed even in the case of in vacuum irradiation, where the formation density of hydroxyl group was suppressed. It can be assumed that damage consisting of two isolated hydroxyl groups within a single repeating unit of PADC is hardly to alter its etching properties. The stable and high density formation of such specific damage would enable the development of more sensitive detectors.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"187 ","pages":"Article 107491"},"PeriodicalIF":1.6,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144665606","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":"First study of X-ray radiation in 45 MW klystrons via Monte Carlo simulations and in situ measurements","authors":"Xirui Zhou ,&nbsp;Yao Yang ,&nbsp;Kuangkuang Ye ,&nbsp;Lei Yang ,&nbsp;Junqiang Zhang ,&nbsp;Xue Yang ,&nbsp;Hanshang Lin ,&nbsp;Zhongquan Li","doi":"10.1016/j.radmeas.2025.107484","DOIUrl":"10.1016/j.radmeas.2025.107484","url":null,"abstract":"<div><div>High-power klystrons are essential for generating microwave signals that accelerate charged particles. However, their operation at such high-power levels, typically the average power ranging from several kilowatts to megawatts, raises concerns regarding unintended X-rays production. This investigation focuses on characterizing the X-ray spectrum and dose equivalent rate generated during high-power test conditions before official operation. Using Monte Carlo simulations, the generation and penetration of X-rays are analyzed. Through detection systems, we analyzed the dose rate distributions of X-rays at various locations of the klystron. The energy of X-rays is obtained by shielding attenuation method. The results indicate that significant X-rays production occurs primarily due to the Bremsstrahlung process, which is associated with high-energy electron impacts on the klystron components. The findings reveal that, while the dose rates remain within regulatory safety limits, radiation monitoring and enhanced local shielding are suggested for ensuring the safety of personnel when working close to the klystron.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"187 ","pages":"Article 107484"},"PeriodicalIF":1.6,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144662091","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}