Radiation Measurements最新文献

{"title":"A correction method between sample mass and EPR intensity in radiation dose reconstruction","authors":"Shuchen Wang ,&nbsp;Zhenlin Jia ,&nbsp;Desheng Xue ,&nbsp;Baotian Pan","doi":"10.1016/j.radmeas.2024.107364","DOIUrl":"10.1016/j.radmeas.2024.107364","url":null,"abstract":"<div><div>In electron paramagnetic resonance (EPR) radiation dose reconstruction, maintaining a consistent mass across a series of aliquots is crucial. However, due to sample limitations or experimental uncertainties, achieving this consistency may not always be possible. To address these challenges and optimize experimental processes, a theoretical model (<span><math><mrow><mi>I</mi><mo>−</mo><mi>M</mi></mrow></math></span> model) was developed to describe the relationship between EPR intensity emanating from a TE₀₁₁ mode cylindrical resonant cavity and sample mass. The model was verified using the TEMPO paramagnetic standard and quartz, a common material employed in dosimetry reconstructions. Based on this model and the evaluation of the modulation magnetic field uniformity, correction methods for EPR intensity in solid powder samples were proposed. The model reveals that the non-uniformity of the microwave magnetic field distribution in the resonant cavity leads to spatial inconsistency in sample responses, resulting in a non-linear relationship between EPR intensity and sample mass, characterized by a “sinusoidal + linear” pattern. The parameter <span><math><msub><mrow><mi>I</mi></mrow><mrow><mi>cen.</mi></mrow></msub></math></span> is recommended as a metric for EPR intensity, as it intrinsically characterizes the spin concentration of the sample regardless of sample mass, thereby enhancing the accuracy of quantitative EPR measurements and equivalent dose evaluation.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"181 ","pages":"Article 107364"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149316","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 neutron energy spectrum study of 241Am-Be based on improved Gravel and PSO algorithms","authors":"Lu-ying Yang,&nbsp;Hai Wan,&nbsp;Ying-Chao Zhang,&nbsp;Xiao-fei Jiang","doi":"10.1016/j.radmeas.2024.107368","DOIUrl":"10.1016/j.radmeas.2024.107368","url":null,"abstract":"<div><div>In the study of neutron energy spectra, different methods have been proposed one after another. Due to their ability to provide efficient parameter optimization and accuracy, Gravel algorithm and PSO algorithm are applied to the deconvolution of ²⁴¹Am-Be neutron source. In this paper, we first obtain the response function of the multi-sphere spectrometer to the ²⁴¹Am-Be neutron source by Geant4 simulation on a platform that is highly consistent with the experimental environment. Then, by combining neutron experimental count rates and neutron response functions, an improved version of Gravel and PSO algorithms is employed to unfold the neutron spectrum of ²⁴¹Am-Be neutron source. In this case, the Gravel algorithm improves the divergence result by adding a scaling factor, and the PSO algorithm applies a Cauchy mutation strategy to escape the local optimal solution. Finally, the unfolded neutron energy spectrum of ²⁴¹Am-Be is compared with the international standard ²⁴¹Am-Be neutron spectrum, and error analysis of the deconvolution is performed using mean square error, average relative deviation, and neutron spectrum quality as indicators. The results show that the improved Gravel and PSO algorithms exhibit superior performance compared to their previous versions and are largely consistent with the international standard ²⁴¹Am-Be neutron energy spectrum curve. The MSE, ARD and Qs values for the improved Gravel algorithm are 0.004%, 1.22% and 1.31% respectively, while those for the improved PSO algorithm are 0.25%, 16.29% and 8.08% respectively. This demonstrates the reliability and applicability of both algorithms in reconstructing neutron energy spectra.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"181 ","pages":"Article 107368"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149808","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":"Thermal stability of the ESR signals of the Al and Ti-Li centers in quartz of tephra","authors":"Naoya Obata ,&nbsp;Shin Toyoda","doi":"10.1016/j.radmeas.2025.107380","DOIUrl":"10.1016/j.radmeas.2025.107380","url":null,"abstract":"<div><div>The thermal stability of the Al and Ti-Li centers in quartz of tephra was systematically investigated in terms of their decay kinetics using two Quaternary tephra samples from Japan, which have independent age estimates, and one modern sediment sample. The Ti-Li center observed in both tephra samples showed a two-step decrease upon heating, indicating the presence of a high temperature part and a low temperature part. The thermal stability of the Al center was found to be similar to the low temperature part of the Ti-Li center, where the characteristic decay times at 19 °C were obtained to be in the order of 10⁴ years. The Ti-Li center showed equivalent doses, with preheating at 240–300 °C, consistent with independent age control. However, the dose response curve of the stable part of the Ti-Li center was saturated at about 2 kGy, which corresponds to an age value of 1 Ma. Therefore, the ESR dating of tephra is possibly limited to samples less than 1 Ma. It was also found that the Ti-Li center is enhanced by heating, around 180 °C in the dose range below 1 kGy. This enhancement has little influence on the dating results for the present samples. We recommend introducing preheating in order to remove the unstable part of the Ti-Li center and to accommodate this increase when examining the dose response.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"181 ","pages":"Article 107380"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143150800","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":"Characterisation and unique behaviours of radiophotoluminescence Ag-activated phosphate glass under high-dose gamma and high-LET particle irradiation","authors":"Toshio Kurobori ,&nbsp;Yuka Miyamoto ,&nbsp;Naoki Takashima ,&nbsp;Yuichi Kitagawa ,&nbsp;Yasuhiro Koguchi","doi":"10.1016/j.radmeas.2025.107376","DOIUrl":"10.1016/j.radmeas.2025.107376","url":null,"abstract":"<div><div>We investigated the optical properties and unique behaviours of radiophotoluminescence (RPL) centres in Ag-activated phosphate glass subjected to a high dose of ⁶⁰Co gamma ray irradiation. Using the absorbance-transmittance excitation-emission matrix technique, we obtained a corrected three-dimensional (3D) matrix that represents the true excitation and emission spectra. Additionally, a similar trend was observed in the dose-dependence of the orange-to-blue RPL intensity ratio for high doses of low linear energy transfer (LET) radiation (in this work) and high LET radiation, such as alpha particles and heavy charged particles (HCPs). However, it was characterised by a rapid decline in orange RPL efficiency (known as ‘LET quenching’). Moreover, we analysed the fluorescence lifetimes and spectra of the components, as observed in the steady-state emission. By tracking the changes in the RPL intensity, fluorescence lifetimes, and peak wavelength shifts as a function of gamma ray dose, we discovered for the first time that blue, green, orange, red, and near-infrared RPL exhibit complex behaviours, such as reduction, enhancement, disappearance, and emergence, while preserving their spectral profiles. We aimed to explore whether Ag-activated phosphate glass could serve as both a dosimeter and tool for evaluating LET values.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"181 ","pages":"Article 107376"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149299","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":"Development of a method for distinguishing alpha particles from other types of radiation using a high-resolution alpha imager","authors":"Yuki Morishita ,&nbsp;Naoki Sagawa ,&nbsp;Makoto Fujisawa ,&nbsp;Shunsuke Kurosawa ,&nbsp;Makoto Sasano ,&nbsp;Masateru Hayashi ,&nbsp;Hiroki Tanaka","doi":"10.1016/j.radmeas.2024.107371","DOIUrl":"10.1016/j.radmeas.2024.107371","url":null,"abstract":"<div><div>The effects of different types of radiation on a high-resolution alpha imager developed using an electron multiplying charge-coupled device (EMCCD) camera were investigated. This imager was originally developed to visualize alpha particles from Pu oxide particles at decommissioning sites. Other types of radiation such as beta particles, gamma rays, and neutrons are also present. The purpose of this study is to investigate the effects of these background radiations on the imager and to develop a method to discriminate between alpha particles and other types of radiation. When measuring gamma rays, and neutrons, the sensor of the EMCCD camera generated high intensity signals due to gamma rays and neutrons. These radiations were identified by image processing. The image values were binarized and the findContours function for detecting edges in an image was applied to count the number of alpha particle spots. The results showed that alpha and gamma (neutron) radiation can be discriminated by using differences in intensity. This method will be useful for visualizing alpha particles at decommissioning sites.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"181 ","pages":"Article 107371"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149321","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":"Ba-Sr fluoride borates as inorganic radiochromic materials","authors":"Sergey V. Rashchenko ,&nbsp;Tatyana B. Bekker ,&nbsp;Alexey V. Davydov ,&nbsp;Boris G. Goldenberg","doi":"10.1016/j.radmeas.2024.107352","DOIUrl":"10.1016/j.radmeas.2024.107352","url":null,"abstract":"<div><div>Radiochromic sensors, which enable express visualization of ionizing radiation by change in color or transparency, are ubiquitous in medical, scientific, and industrial applications. Most of the currently known radiochromic materials belong to organic compounds, while the potential of <em>inorganic</em> materials in terms of radiochromicity remains nearly unexplored. Here we report the measurements of dose sensitivity of radiochromic coloration intensity and decay kinetics of radiation-induced color centers for inorganic Ba-Sr fluoride borates with the compositions Ba₇(BO₃)_3.5F_3.5 and Ba₃Sr₄(BO₃)₄F₂. Experiments with irradiation of these polycrystalline materials using broadband synchrotron radiation (5–17 keV) revealed that the Ba₃Sr₄(BO₃)₄F₂ material has dose sensitivity of radiochromic coloration potentially suitable for measurements of doses from several cGy to ∼10 Gy air kerma. The Ba₇(BO₃)_3.5F_3.5 material demonstrated a slightly lower dose sensitivity of radiochromic coloration than Ba₃Sr₄(BO₃)₄F₂, but also revealed the possibility of quick bleaching of the radiochromic coloration using intense visible light, which may be used in the development of reusable radiochromic sensors.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"181 ","pages":"Article 107352"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149804","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":"Development of A handheld pressurized ionization chamber for gamma monitoring","authors":"Recep Bıyık ,&nbsp;Osman Alaçayır ,&nbsp;Tamer Yalçın ,&nbsp;Tuncay Tuna","doi":"10.1016/j.radmeas.2025.107385","DOIUrl":"10.1016/j.radmeas.2025.107385","url":null,"abstract":"<div><div>In this study, it is aimed to design and manufacture an ionization chamber (IC) in dimensions suitable for use in handheld radiation meter detectors. In the measurements made in the region of 0.2 mR/h and 6 R/h dose rates, it was determined that the dose current linearity was at high levels (99%) and the ionization current sensitivity was 1.7 x 10⁻⁷ A per R/h at 10 atm (130 psig) pressure. In the saturation characteristic study of the ionization chamber at different dose rates, it was observed that the plateau region was reached at ≈200 V applied chamber potential values. The effect of general recombination was analyzed by using two voltage method and fitting techniques. The collection efficiency factor of the ionization chamber at low and high dose rates (between 2 mR/h-5R/h) was calculated for both techniques and found to be in agreement. The designed and fabricated ionization chamber tube has been demonstrated to satisfy the requisite criteria and is thus suitable for utilization in handheld radiation meter detectors.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"181 ","pages":"Article 107385"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149293","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 new and general efficiency calibration methodology for Ge detectors using LabSOCS","authors":"A. Barba-Lobo","doi":"10.1016/j.radmeas.2025.107374","DOIUrl":"10.1016/j.radmeas.2025.107374","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The measurement of natural and artificial radionuclides is really needed in many research fields such as radioecology, radiobiology, radiological protection, medical physics and environmental radioactivity. The gamma-ray spectrometry using Ge detectors has become one the most employed radiometric techniques, where a proper efficiency calibration based on the full-energy peak efficiency (&lt;em&gt;FEPE&lt;/em&gt;) is essential for the measurement of radionuclides. To obtain the &lt;em&gt;FEPEs&lt;/em&gt;, the use of simulation programs, especially LabSOCS, has become generalized. However, when obtaining the &lt;em&gt;FEPEs&lt;/em&gt; by LabSOCS, the reproduction of each geometry is usually time consuming. Moreover, when using LabSOCS, there are important limitations regarding the chemical composition that is possible to specify for each sample. For these previous reasons, this study aims to develop a novel and general efficiency calibration methodology for Ge detectors using LabSOCS for cylindrical geometries. For this, a general analytical function was obtained for the simulated &lt;em&gt;FEPEs&lt;/em&gt; for the calibration sample (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;ε&lt;/mi&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, water in this case) depending on the sample thickness (&lt;em&gt;h&lt;/em&gt;), internal geometry diameter (&lt;em&gt;d&lt;/em&gt;) and gamma emission energy (&lt;em&gt;E&lt;/em&gt;&lt;sub&gt;&lt;em&gt;γ&lt;/em&gt;&lt;/sub&gt;), where a multiple fitting procedure was developed consisting in three steps: 1. &lt;em&gt;FEPEs&lt;/em&gt; vs &lt;em&gt;h&lt;/em&gt; (&lt;em&gt;h&lt;/em&gt; = 5–50 mm), fixing &lt;em&gt;d&lt;/em&gt; and &lt;em&gt;E&lt;/em&gt;&lt;sub&gt;&lt;em&gt;γ&lt;/em&gt;&lt;/sub&gt;, obtaining the parameters &lt;em&gt;p&lt;/em&gt;&lt;sub&gt;&lt;em&gt;h&lt;/em&gt;&lt;/sub&gt; from these fits, 2. &lt;em&gt;p&lt;/em&gt;&lt;sub&gt;&lt;em&gt;h&lt;/em&gt;&lt;/sub&gt; vs &lt;em&gt;d&lt;/em&gt; (&lt;em&gt;d&lt;/em&gt; = 7–70 mm), fixing &lt;em&gt;E&lt;/em&gt;&lt;sub&gt;&lt;em&gt;γ&lt;/em&gt;&lt;/sub&gt;, obtaining &lt;em&gt;p&lt;/em&gt;&lt;sub&gt;&lt;em&gt;d&lt;/em&gt;&lt;/sub&gt;, and 3. &lt;em&gt;p&lt;/em&gt;&lt;sub&gt;&lt;em&gt;d&lt;/em&gt;&lt;/sub&gt; vs &lt;em&gt;E&lt;/em&gt;&lt;sub&gt;&lt;em&gt;γ&lt;/em&gt;&lt;/sub&gt; (&lt;em&gt;E&lt;/em&gt;&lt;sub&gt;&lt;em&gt;γ&lt;/em&gt;&lt;/sub&gt; = 46–1460 keV), obtaining &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;p&lt;/mi&gt;&lt;msub&gt;&lt;mi&gt;E&lt;/mi&gt;&lt;mi&gt;γ&lt;/mi&gt;&lt;/msub&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. For all the fits, the obtained &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msubsup&gt;&lt;mi&gt;χ&lt;/mi&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msubsup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; values were less than the critical &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msubsup&gt;&lt;mi&gt;χ&lt;/mi&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msubsup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; ones. Then, the general &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;ε&lt;/mi&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;/msub&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mi&gt;h&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;msub&gt;&lt;mi&gt;E&lt;/mi&gt;&lt;mi&gt;γ&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; function was also obtained for any problem sample (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;ε&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;) using an analytical function of the self-attenuation correction factor (&lt;em&gt;f&lt;/em&gt;&lt;sub&gt;&lt;em&gt;a&lt;/em&gt;&lt;/sub&gt;). The applicability range of the &lt;em&gt;f&lt;/em&gt;&lt;sub&gt;&lt;em&gt;a&lt;/em&gt;&lt;/sub&gt; function was comprehensively analyzed for a wide range of chemical compositions, apparent densities (&lt;em&gt;ρ&lt;/em&gt;), &lt;em&gt;h&lt;/em&gt;, &lt;em&gt;d&lt;/em&gt;, and &lt;em&gt;E&lt;/em&gt;&lt;sub&gt;&lt;em&gt;γ&lt;/em&gt;&lt;/sub&gt;, comparing the results obtained by the &lt;em&gt;f&lt;/em&gt;&lt;sub&gt;&lt;em&gt;a&lt;/em&gt;&lt;/sub&gt; function and LabSOCS,","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"181 ","pages":"Article 107374"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149317","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":"Evaluation of dosimetric properties of LiAlO2:Gd for detection and discrimination of thermal neutron in mixed field environment","authors":"Pragya R. Jopat ,&nbsp;Sabyasachi Paul ,&nbsp;M.S. Kulkarni ,&nbsp;Shashwati Sen","doi":"10.1016/j.radmeas.2024.107370","DOIUrl":"10.1016/j.radmeas.2024.107370","url":null,"abstract":"<div><div>The study demonstrates the capability of the newly developed LiAlO₂:Gd³⁺, a thermal neutron sensitive phosphor as a potential dosimeter for personnel dosimetry applications. The co-existence of both photon and neutron sensitive materials expands its application domain in both photon and neutron radiation environments. The phosphor has been tested in both photon and neutron reference fields to quantify its sensitivity to both radiation types. Subsequently after evaluating the photon sensitivity in the reference photon field, the neutron ambient dose equivalent quantification has been performed in the mixed radiation environment of the thermal neutrons. Extendibility of the phosphor for simultaneous evaluation of the neutron and photons fractions in a mixed radiation field has also been investigated with and without applying a Cd-filter to eliminate the thermal neutrons. The conventional dual dosimeter approach with preferential sensitivity to a specified radiation type has also been revisited for validation purposes with a comparison between the thermo-luminescence response of three types of dosimeters, MCP-600 (⁶LiF:Mg,Cu,P), MCP-700 (⁷LiF:Mg,Cu,P) and LiAlO₂:Gd³⁺ (0.5% mol). The newly developed phosphor material has been applied in pair with the commercially available photon sensitive MCP-700 detectors for quantitative estimation of the neutron fraction. The response variations were verified with MCP-600 and MCP-700 dosimeter pair at different irradiation intervals in the standard thermal neutron reference fields. The dose estimates were found to be reproducible and precise in comparison to the conventional (MCP-600 and MCP-700) dosimeter pair with enhanced thermo-luminescence response per unit thermal neutron ambient dose equivalent in the mixed radiation environment.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"181 ","pages":"Article 107370"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149318","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":"Three-dimensional electron paramagnetic resonance (EPR) imaging of an X-ray-irradiated bovine tooth: A feasibility study","authors":"Yukihiro Arai ,&nbsp;Mai Taguchi ,&nbsp;Oki Mitarai ,&nbsp;Ichiro Yamaguchi ,&nbsp;Hideo Sato-Akaba ,&nbsp;Shingo Matsumoto ,&nbsp;Minoru Miyake ,&nbsp;Hiroshi Hirata","doi":"10.1016/j.radmeas.2025.107381","DOIUrl":"10.1016/j.radmeas.2025.107381","url":null,"abstract":"<div><div>This study aimed to demonstrate the feasibility of three-dimensional (3D) mapping of an X-ray-irradiated bovine tooth using 750-MHz continuous-wave electron paramagnetic resonance (EPR). A bovine tooth that received 50-Gy X-ray was used as a dosimetry sample. To enhance the sensitivity of EPR detection, we used an ultra-low-noise saturated power amplifier following an RF synthesizer. Moreover, the automatic tuning control (ATC) system, which locks the frequency of the radiofrequency (RF) resonator to the RF carrier frequency, was combined with another RF frequency adjustment system for the RF synthesizer to enable long-term data acquisition over several hours. A 4-hydroxy-TEMPO radical solution was measured as a standard EPR signal source to investigate the enhancement of signal sensitivity. The radiation-induced EPR signals in tooth enamel were reconstructed using the algebraic reconstruction technique (ART). The signal-to-noise ratios achieved for the 4-hydroxy-TEMPO radical solution and a 50-Gy irradiated bovine tooth were twice as high as those obtained previously. Radiation-induced signals in the bovine tooth were mapped in 3D space for 3 h 45 min. The spatial resolution in the 3D map reached 2.1 mm. While low-field EPR was considered to be less sensitive for mapping the absorbed dose of an irradiated tooth, we demonstrated that low-field EPR at 26.8 mT (750 MHz) is applicable to the 3D mapping of 50-Gy-irradiated tooth enamel. Our findings represent a step towards a technology for absorbed-dose mapping of human teeth in cases of accidental exposure to head and neck cancer patients.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"181 ","pages":"Article 107381"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149294","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}