Applied Radiation and Isotopes最新文献

{"title":"Study of the out-of-field dose from an accelerator-based neutron source for boron neutron capture therapy","authors":"","doi":"10.1016/j.apradiso.2024.111458","DOIUrl":"10.1016/j.apradiso.2024.111458","url":null,"abstract":"<div><p>One important issue in Boron Neutron Capture Therapy is the delivered dose to the tissues outside the tumor. An international standard for light ion beam systems sets two recommended limits for out-of-field dose based on distance from the field edge: maximum absorbed dose from all radiation types shall not exceed 0.5 % of the maximum dose at distances 15 cm to 50 cm from the field edge. At distances <span><math><mrow><mo>&gt;</mo><mn>50</mn></mrow></math></span> cm from the field edge, the maximum absorbed dose shall not exceed 0.1 %. This paper is a continuation of our previous works focused on the design of an accelerator-based neutron source for BNCT. We already designed a novel Beam Shape Assembly which meets the IAEA criteria for BNCT treatments. Using this BSA, in the present work, we characterize by Monte Carlo simulations the dose outside the neutron field. The out-of-field dose has been assessed via estimates using the ambient and equivalent dose. Also the boron uptake in healthy tissues has been analyzed for the equivalent dose computation. It is concluded that our design for a future accelerator-based source for BNCT meets reasonably well the criteria defined from other forms of radiotherapy on both equivalent and effective dose outside the field.</p></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0969804324002860/pdfft?md5=dcb830510f2322299adfbe4d4ba46a0b&pid=1-s2.0-S0969804324002860-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141845657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the thermoluminescence characteristics of smartphone screen safety glasses for retrospective dosimetry applications","authors":"","doi":"10.1016/j.apradiso.2024.111457","DOIUrl":"10.1016/j.apradiso.2024.111457","url":null,"abstract":"<div><p>In clinical settings, standard dosimeters might miss radiation mishaps. Retrospective dosimeters could help to track personnel (such as patients and other staff who don't wear dosimeters) exceeding safe limits and assess long-term exposure trends. This study has investigated key thermoluminescence (TL) dosimetric characteristics, including the glow curve structure, dose-response, energy dependence, sensitivity and fading of various safety glasses that are used as screen protectors of smartphones subjected to photon irradiation. Among the studied glasses, the HD Anti-Peep safety glass for iPhone has been found to exhibit a linear dose-response with a regression coefficient of 99% within the dose range of 2–10 Gy. Moreover, all the safety glasses showed independence with respect to photon energy of 6 MV and 10 MV. The TL glow curves of the samples showed a broad glow peak between 125 °C and 325 °C at 10 Gy. The TL kinetic parameters of the safety glasses were also studied by analyzing the glow curves using the peak shape and initial rise method. The geometric factor (<em>μ</em>_<em>g</em>) is found to be within the range of 0.43–0.53, which indicates the suitability of applying Chen's general-order formula to calculate the kinetic parameters such as activation energy, frequency factor and trap lifetime. The activation energy (<em>E</em>) and frequency factor (s) are found in the range of 0.31–0.54 eV and 4.55 × 10³ to 2.12 × 10⁶ s⁻¹ respectively obtained via the peak shape method. The relatively long trap lifetime and observed thermoluminescence features indicate that the HD Anti-Peep safety glass offers a better option to estimate dose retrospectively to ensure the safety of human health.</p></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141787106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stopping criteria for neutron spectrum unfolding algorithms","authors":"","doi":"10.1016/j.apradiso.2024.111456","DOIUrl":"10.1016/j.apradiso.2024.111456","url":null,"abstract":"<div><p>Neutron spectrum unfolding is a crucial process in radiation protection and dosimetry. Unfolding codes using iterative algorithms require a criterion to stop the iterations. One approach often relies on the Root Mean Square Error (RMSE) criterion to assess the convergence of iterative algorithms. The aim of this work is to present a new criteria: Average Ratio Scaled (AVGS) and Relative Change in AVGS (dAVGS) to address specific challenges associated with RMSE. Extensive validation tests were conducted, covering a range of scenarios with results showing high level of agreement between the unfolded spectra and the reference.</p></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141780189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and characterization of Staphylococcus aureus-hydrogel-based radiation dosimeter","authors":"","doi":"10.1016/j.apradiso.2024.111455","DOIUrl":"10.1016/j.apradiso.2024.111455","url":null,"abstract":"<div><p>In the search of innovative methods within radiation dosimetry to provide solutions to the high demanding modern ionizing radiation applications, this work proposes an original approach to combine microorganisms and gel dosimetry characteristics by adapting biotechnology and molecular biology procedures. The design of bacterial culture media and the evaluation of viability as systems for radiation dosimetry are reported. In preliminary assessments, a highly promising dose-response has been observed for samples stored at 4 °C, displaying a linear trend within the investigated dose range. This underscores a promising performance, indicating the potential utility of the system as a radiation dosimeter.</p></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141780190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced sorption of strontium radionuclides onto a modified molybdenum titanate composite","authors":"","doi":"10.1016/j.apradiso.2024.111447","DOIUrl":"10.1016/j.apradiso.2024.111447","url":null,"abstract":"<div><p>A study was conducted to investigate the sorption of ⁸⁵Sr from aqueous solutions using a fabricated magnesium molybdenum titanate (MgMoTi) composite. The MgMoTi composites were synthesized through the co-precipitation technique and characterized using different analytical tools, including FT-IR, XRD, SEM, and EDX. The sorption studies focused on ⁸⁵Sr and examined factors such as shaking time, pH, ionic strength, temperature, initial ion concentration, and saturation capacity. The results obtained from the study indicated that, under optimum sorption conditions, the saturation capacity for ⁸⁵Sr onto S-4 and S-5 was determined to be 23.31 and 37.72 mg g⁻¹, respectively. The sorption of ⁸⁵Sr exhibited dependence on pH and ionic strength. The kinetics of the sorption process followed the pseudo-2nd-order model, while the thermodynamics revealed an endothermic and spontaneous nature. Desorption studies revealed that 0.1 M HCl was the most effective eluent for the complete recovery of ⁸⁵Sr. Furthermore, the recycling results demonstrated the excellent recyclability of MgMoTi, suggesting its potential application as a sorbent for the removal of ⁸⁵Sr from aqueous solutions. Overall, the study highlights MgMoTi as a promising composite with practical utility in the sorption of ⁸⁵Sr from aqueous solutions.</p></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141756770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Real-time gamma-ray energy spectrum / dose monitor with k-α method based on sequential bayesian estimation","authors":"","doi":"10.1016/j.apradiso.2024.111454","DOIUrl":"10.1016/j.apradiso.2024.111454","url":null,"abstract":"<div><p>Medical applications of radiation have been widely spread until now. However, the exposure of medical staff is sometimes overlooked, because treatment of patients is the first priority. The purpose of this study is to develop a small and light monitor that can measure the energy spectrum and dose of gamma-rays at the same time in real-time for medical applications. Using the monitor, the medical staff could be guided to be more aware ofthe risk of radiation, and finally the exposure to them could be substantially suppressed. So far, a CsI scintillator has been chosen as a detection device of gamma-rays and combined with a Multi-Pixel Photon Counter (MPPC) to develop a prototype monitor. Then we confirmed its basic performance with standard gamma-ray sources. To achieve the real-time measurement, α method (sequential Bayesian estimation) was adopted and improved to propose a new unfolding process, named <em>k</em>-α method, with which the convergence speed could really be accelerated to realize real-time measurement. Also, gamma-ray measurements with a mixed source of ¹³³Ba, ¹³⁷Cs and ⁶⁰Co were carried out to confirm the validity of the present monitor. As a result, it was found that gamma-ray energy spectrum could be estimated successfully in several-tens seconds in the field of around 6 μSv/h. For the dose estimation, the correct values could be estimated just after starting measurement.</p></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0969804324002823/pdfft?md5=7c681d3be9a9325c75355da562219452&pid=1-s2.0-S0969804324002823-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141780191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of plastic scintillator with better performance than the commercial counterpart (UPS-923A) and effect of fluorophore composition on light output","authors":"","doi":"10.1016/j.apradiso.2024.111453","DOIUrl":"10.1016/j.apradiso.2024.111453","url":null,"abstract":"<div><p>In this study we have synthesized polystyrene based plastic scintillators (PS) loaded with commercially available fluorophores like <em>p</em>-Terphenyl and 1,4-bis(5-phenyloxazol-2-yl) benzene (POPOP). Optimum concentration of the fluorophores in the synthesized PS was determined. The PS exhibited 1.55 ± 0.05 times better light output than UPS-923A, a commercial PS. Emission maxima were obtained at 423 nm with an energy linearity of 99.78% up to 1.061 MeV. Radiation damage of PS by Co-60 irradiation led to 22.3% loss of light yield at 50 kGy radiation dose which is better than the commercial one. The loss of light output in the PS due to radiation damage was because of the degradation of polystyrene matrix rather than the fluorophores.</p></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141765024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved titanium-44 purification process for establishing a high apparent molar activity titanium-44/scandium-44 generator","authors":"","doi":"10.1016/j.apradiso.2024.111451","DOIUrl":"10.1016/j.apradiso.2024.111451","url":null,"abstract":"<div><p>⁴⁴Sc-radiopharmaceuticals are gaining more interest but still lack availability. The proof of principle of a⁴⁴Ti/⁴⁴Sc generator, which can produce ⁴⁴Sc daily, has been established but with some limitations and drawbacks. Despite recent advances, separation of ⁴⁴Ti from massive quantities of scandium target material is still cumbersome. In this work, the improved radiochemical separation of ⁴⁴Ti from residual scandium target material was carried out by precipitation of Sc with fluoride ions. Furthermore, two approaches were used to set up a high apparent molar activity small-scale generator. The first method relied on extraction chromatography for fine purification using a DGA resin, followed by loading of the purified ⁴⁴Ti onto a ZR resin column. In the second method, ⁴⁴Ti was loaded on the ZR resin directly after the precipitation step. This second method was used to set up a generator of 370 kBq and evaluate by radiolabeling. An apparent molar activity of 2 MBq/nmol was obtained for the radiolabeling with DOTA, the most common and suitable chelate for scandium. This result is comparable with previously published data on ⁴⁴ ^m/44Sc.</p></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141851297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lung counting with a highly segmented HPGe detector","authors":"","doi":"10.1016/j.apradiso.2024.111452","DOIUrl":"10.1016/j.apradiso.2024.111452","url":null,"abstract":"<div><p>A highly segmented High-Purity Germanium (HPGe) detector was used to measure ²⁴¹Am activity located inside the lungs of an anthropomorphic phantom with various active and passive shield configurations. It was found that the background suppression shield does not play a significant role in reducing the Minimum Detectable Activity (MDA) after veto, based on the segmentation in the depth direction of the HPGe, when measuring low-energy gamma rays. A reduction of up to 57% in the MDA was achieved. The MDA could be further improved by a thinner lateral segmentation and an optimized anti-Compton shield coupled with an active or passive backplate. The new detector application would be particularly useful in mobile whole-body counting units, where the natural background radiation poses a challenge when measuring low-energy gamma rays.</p></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S096980432400280X/pdfft?md5=6ec0f99177d14d917188d762239fbb0a&pid=1-s2.0-S096980432400280X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141765025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"National programme for the reliability of ionizing radiation measurements based on inter-laboratory comparisons (ILCs): ILC n°2 ‘radiopharmaceutical activities’","authors":"","doi":"10.1016/j.apradiso.2024.111449","DOIUrl":"10.1016/j.apradiso.2024.111449","url":null,"abstract":"<div><p>A national Inter-Laboratory Comparisons (ILCs) programme was organized in Italy in 2022 by the Italian National Institute of Ionizing Radiation Metrology (INMRI), belonging to ENEA (Italian National Agency for New Technologies, Energy and Sustainable Economic Development), under the auspices of the Ministry of Enterprises and Made in Italy (Mimit ex MiSe). Within this ILCs programme, six inter-laboratory comparisons were organized, including the ILC-2 which focused on activity measurements carried out with radionuclide calibrators commonly used in the nuclear medicine departments of the participants.</p><p>The focus was on three short-lived radionuclides - ^99mTc, ¹⁸F, ¹⁷⁷Lu - commonly employed in nuclear medicine for both diagnostic and therapeutic purposes. All presented results were compared with the reference values provided by ENEA-INMRI to ensure the traceability of measurements to the national primary activity standards. The observed deviation from the reference values of the measured activity were mainly within <span><math><mrow><mo>±</mo></mrow></math></span> 10% (100% for ¹⁸F, 91.7% for ^99mTc, 100% for ¹⁷⁷Lu). The <em>E</em>_<em>n</em> statistical estimator was used to assess the participants’ ability to estimate uncertainty in the provided activity values. The obtained values revealed that, in certain instances, the involved laboratories did not achieve the correct results for <em>E</em>_<em>n</em> (with failure rates of 22.7%, 16.7%, 12.5% for ¹⁸F, ^99mTc, ¹⁷⁷Lu, respectively), despite deviations from the reference values falling within the <span><math><mrow><mo>±</mo></mrow></math></span> 10%. The aim of ILC-2 was to harmonize the activity measurements in the country within the field of nuclear medicine for the specific radionuclides studied and enhance the measurement capabilities of the participants.</p></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S096980432400277X/pdfft?md5=53c0d743bf0d3a8e3a88d4a1a46a0bf7&pid=1-s2.0-S096980432400277X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141736682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}