Pub Date : 2025-11-13DOI: 10.1016/j.nimb.2025.165942
Gianluca Quarta , Istenc Engin , Theodora Eleftheriou , Lucio Maruccio , Marisa D’Elia , Dalila Peccarrisi , Mattia Fragola , Lucio Calcagnile
The Centre of Applied Physics, Dating, and Diagnostics (CEDAD) at the University of Salento collaborates with the Committee on Missing Persons in Cyprus (CMP) to analyze skeletal remains of individuals who went missing during the 1963–64 inter-communal conflict and the 1974 events. Supported by the United Nations, the CMP aims to locate, identify, and return the remains to families, a process complicated by poor preservation of skeletal remains, complex burial contexts, and limited contextual information. Radiocarbon dating is a key part of the CMP’s analysis procedures, helping establish whether remains fall within the CMP mandate and providing details such as the individual’s year of birth. This paper reviews the application of radiocarbon dating of bone samples, addressing challenges like dietary offsets and carbon turnover models while demonstrating its significance in refining identification processes. Case studies highlight its utility in both relevant and unrelated contexts to the CMP’s mission, emphasizing its broader contributions to historical and forensic investigations.
{"title":"14C dating in forensics: The Committee on Missing Persons in Cyprus (CMP) and the identification of skeletal remains of missing persons","authors":"Gianluca Quarta , Istenc Engin , Theodora Eleftheriou , Lucio Maruccio , Marisa D’Elia , Dalila Peccarrisi , Mattia Fragola , Lucio Calcagnile","doi":"10.1016/j.nimb.2025.165942","DOIUrl":"10.1016/j.nimb.2025.165942","url":null,"abstract":"<div><div>The Centre of Applied Physics, Dating, and Diagnostics (CEDAD) at the University of Salento collaborates with the Committee on Missing Persons in Cyprus (CMP) to analyze skeletal remains of individuals who went missing during the 1963–64 inter-communal conflict and the 1974 events. Supported by the United Nations, the CMP aims to locate, identify, and return the remains to families, a process complicated by poor preservation of skeletal remains, complex burial contexts, and limited contextual information. Radiocarbon dating is a key part of the CMP’s analysis procedures, helping establish whether remains fall within the CMP mandate and providing details such as the individual’s year of birth. This paper reviews the application of radiocarbon dating of bone samples, addressing challenges like dietary offsets and carbon turnover models while demonstrating its significance in refining identification processes. Case studies highlight its utility in both relevant and unrelated contexts to the CMP’s mission, emphasizing its broader contributions to historical and forensic investigations.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"570 ","pages":"Article 165942"},"PeriodicalIF":1.4,"publicationDate":"2025-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526852","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}
Pub Date : 2025-11-12DOI: 10.1016/j.nimb.2025.165940
Dimpal Saikia , Monuj Gogoi , Rasna Baruah , Bhargab Boruah , Hritik Gogoi , Nabajyoti Pandit , Naba Kumar Kalita , A. Barthakur , M. Baro , M.M. Devi , G.C. Wary , J.J. Das , M. Patgiri , J. Sharma , V.M. Datar , R. Raut , S. Ghugre , P.C. Rout , S. Santra , B. Jyrwa , R. Brahma
We present the work done towards setting up an AD-BNCT (Accelerator Driven Boron Neutron Capture Therapy) facility in the North- Eastern Region of India. This includes optimization of the neutron Beam Shaping Assembly (BSA) and Beam Optics for the proposed facility. Validation of simulation software is performed against similar data from literature. We devised a methodology maintaining the accuracy of the results. The value of fepithermal ∼109n/cm2/s for 0.6 mA current of 4 MeV protons. At the exit window, the neutron flux ratios are fepithermal/ffast ∼29 and fepithermal/fthermal ∼130, while the values of Dfast/fepithermal ∼0.479 × 10−13 Gy/cm2 and Dγ/fepithermal ∼4.65 × 10−13 Gy/cm2. The first four parameters conform to the IAEA recommendations. The dose to healthy tissue is found to be 60 % less than tumor tissue with our BSA design. Further optimization of the collimator design could reduce the Dγ/fepithermal, which can be considered in future study.
{"title":"Design and optimization of a neutron beam shaping assembly for AD-BNCT applications (D3) at Cotton University by CUPAC-NE collaboration","authors":"Dimpal Saikia , Monuj Gogoi , Rasna Baruah , Bhargab Boruah , Hritik Gogoi , Nabajyoti Pandit , Naba Kumar Kalita , A. Barthakur , M. Baro , M.M. Devi , G.C. Wary , J.J. Das , M. Patgiri , J. Sharma , V.M. Datar , R. Raut , S. Ghugre , P.C. Rout , S. Santra , B. Jyrwa , R. Brahma","doi":"10.1016/j.nimb.2025.165940","DOIUrl":"10.1016/j.nimb.2025.165940","url":null,"abstract":"<div><div>We present the work done towards setting up an AD-BNCT (Accelerator Driven Boron Neutron Capture Therapy) facility in the North- Eastern Region of India. This includes optimization of the neutron Beam Shaping Assembly (BSA) and Beam Optics for the proposed facility. Validation of simulation software is performed against similar data from literature. We devised a methodology maintaining the accuracy of the results. The value of f<sub>epithermal</sub> ∼10<sup>9</sup>n/cm<sup>2</sup>/s for 0.6 mA current of 4 MeV protons. At the exit window, the neutron flux ratios are f<sub>epithermal</sub>/f<sub>fast</sub> ∼29 and f<sub>epithermal</sub>/f<sub>thermal</sub> ∼130, while the values of D<sub>fast</sub>/f<sub>epithermal</sub> ∼0.479 × 10<sup>−13</sup> Gy/cm<sup>2</sup> and D<sub>γ</sub>/f<sub>epithermal</sub> ∼4.65 × 10<sup>−13</sup> Gy/cm<sup>2</sup>. The first four parameters conform to the IAEA recommendations. The dose to healthy tissue is found to be 60 % less than tumor tissue with our BSA design. Further optimization of the collimator design could reduce the D<sub>γ</sub>/f<sub>epithermal</sub>, which can be considered in future study.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"570 ","pages":"Article 165940"},"PeriodicalIF":1.4,"publicationDate":"2025-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526851","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}
Pub Date : 2025-11-11DOI: 10.1016/j.nimb.2025.165936
Zhongyang Tan , Jiming Jia , Lijun Chen , Lixia Tian , Wenjie Zheng , Bang Yao , Xianghai Ran
In this study, gamma PVDF films were irradiated with 35, 92 and 173 kGy respectively, and characterized by gel content, thermal and tensile property analysis. The results show that the irradiation can induce high gel content (> 35 %) and enhanced transparency without significantly reducing its thermal stability. The irradiation can significantly increase the dimensional stability of PVDF film beyond the melting point due to the formation of irradiation-induced crosslinking structure. However, the irradiation caused a decrease in Tg and creep resistance at 90 °C for PVDF film, which can be attributed to the formation of PVDF chain with higher mobility resulting from the irradiation. The irradiation can cause a significant decrease in the elongation at break of PVDF film, but the irradiation at 92 kGy increased the tensile strength of PVDF film from 52.9 MPa to 55.1 MPa, and the elastic modulus from 1.28 GPa to 1.36 GPa, respectively.
{"title":"Characterization of highly transparent crosslinked gamma Polyvinylidene fluoride films prepared by the electron beam irradiation","authors":"Zhongyang Tan , Jiming Jia , Lijun Chen , Lixia Tian , Wenjie Zheng , Bang Yao , Xianghai Ran","doi":"10.1016/j.nimb.2025.165936","DOIUrl":"10.1016/j.nimb.2025.165936","url":null,"abstract":"<div><div>In this study, gamma PVDF films were irradiated with 35, 92 and 173 kGy respectively, and characterized by gel content, thermal and tensile property analysis. The results show that the irradiation can induce high gel content (> 35 %) and enhanced transparency without significantly reducing its thermal stability. The irradiation can significantly increase the dimensional stability of PVDF film beyond the melting point due to the formation of irradiation-induced crosslinking structure. However, the irradiation caused a decrease in T<sub>g</sub> and creep resistance at 90 °C for PVDF film, which can be attributed to the formation of PVDF chain with higher mobility resulting from the irradiation. The irradiation can cause a significant decrease in the elongation at break of PVDF film, but the irradiation at 92 kGy increased the tensile strength of PVDF film from 52.9 MPa to 55.1 MPa, and the elastic modulus from 1.28 GPa to 1.36 GPa, respectively.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"570 ","pages":"Article 165936"},"PeriodicalIF":1.4,"publicationDate":"2025-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526884","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}
Pub Date : 2025-11-11DOI: 10.1016/j.nimb.2025.165948
Brayden Dean, Timothy Villarreal, Scott Williams
A study was performed to investigate how differences in mass density, mean excitation energy, and the number of conduction electrons per atom affect the bremsstrahlung produced when 10-keV electrons are incident on thick diamond and graphite substrates. The Monte Carlo code, PENELOPE, was used to observe how mass density, mean excitation energy, and the number of conduction electrons per atom independently influence the bremsstrahlung produced by 10-keV electrons incident on a carbon substrate. Experiments were also performed to determine whether the cumulative effects of the aforementioned factors could be observed by comparing the bremsstrahlung produced by electrons accelerated toward diamond and graphite substrates. The results of the experiments were in relatively good agreement with the data generated by PENELOPE, which suggest that the higher mass density and mean excitation energy of diamond result in slightly higher bremsstrahlung probabilities.
{"title":"Bremsstrahlung produced by 10-keV electrons incident on carbon allotropes","authors":"Brayden Dean, Timothy Villarreal, Scott Williams","doi":"10.1016/j.nimb.2025.165948","DOIUrl":"10.1016/j.nimb.2025.165948","url":null,"abstract":"<div><div>A study was performed to investigate how differences in mass density, mean excitation energy, and the number of conduction electrons per atom affect the bremsstrahlung produced when 10-keV electrons are incident on thick diamond and graphite substrates. The Monte Carlo code, PENELOPE, was used to observe how mass density, mean excitation energy, and the number of conduction electrons per atom independently influence the bremsstrahlung produced by 10-keV electrons incident on a carbon substrate. Experiments were also performed to determine whether the cumulative effects of the aforementioned factors could be observed by comparing the bremsstrahlung produced by electrons accelerated toward diamond and graphite substrates. The results of the experiments were in relatively good agreement with the data generated by PENELOPE, which suggest that the higher mass density and mean excitation energy of diamond result in slightly higher bremsstrahlung probabilities.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"570 ","pages":"Article 165948"},"PeriodicalIF":1.4,"publicationDate":"2025-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526853","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}
Pub Date : 2025-11-10DOI: 10.1016/j.nimb.2025.165945
Ahmed Bannan , Hamza Sekkat , Oussama El Mouden , Abdellah Khallouqi , Redouane El Baydaoui , Mustapha Bougteb , Omar El Rhazouani , Kamal Saidi , Zakaria Ait Elcadi , Mounir Mkimel
Accurate dosimetry in small photon fields is challenged by detector size and electronic disequilibrium. We compared a microSilicon diode, a microDiamond detector and Gafchromic EBT3 film for 6 and 10 MV beams in flattened and flattening-filter-free modes (FFF). Film served as high-spatial-resolution comparator (absolute dose referenced to ion chamber). Film calibration (0–360.9 cGy) was reproducible within ≤2 % with cubic fits (R2 ≈ 1). Percentage-depth-dose curves from both diodes agreed within 2.1 % across field sizes. Lateral profiles showed sharper penumbrae with microSilicon, with deviations <1.5 % against film, cross-plane differences reached ∼5 % for 5 × 5 mm2 but were negligible for ≥30 × 30 mm2. Full-width-at-half-maximum analysis indicated slightly broader penumbrae at 10 MV (∼+0.1 mm) and narrower in-plane penumbrae for FFF beams. Output factors ranged from ∼0.70 (5 × 5 mm2) to 1.00 (40 × 40 mm2). Mainly, microSilicon agreed more closely with film than microDiamond in the smallest fields.
{"title":"Investigating the performance of the novel microSilicon diode detector for high-resolution dosimetry in radiotherapy: Flat and FFF beams across multiple energies","authors":"Ahmed Bannan , Hamza Sekkat , Oussama El Mouden , Abdellah Khallouqi , Redouane El Baydaoui , Mustapha Bougteb , Omar El Rhazouani , Kamal Saidi , Zakaria Ait Elcadi , Mounir Mkimel","doi":"10.1016/j.nimb.2025.165945","DOIUrl":"10.1016/j.nimb.2025.165945","url":null,"abstract":"<div><div>Accurate dosimetry in small photon fields is challenged by detector size and electronic disequilibrium. We compared a microSilicon diode, a microDiamond detector and Gafchromic EBT3 film for 6 and 10 MV beams in flattened and flattening-filter-free modes (FFF). Film served as high-spatial-resolution comparator (absolute dose referenced to ion chamber). Film calibration (0–360.9 cGy) was reproducible within ≤2 % with cubic fits (R<sup>2</sup> ≈ 1). Percentage-depth-dose curves from both diodes agreed within 2.1 % across field sizes. Lateral profiles showed sharper penumbrae with microSilicon, with deviations <1.5 % against film, cross-plane differences reached ∼5 % for 5 × 5 mm<sup>2</sup> but were negligible for ≥30 × 30 mm<sup>2</sup>. Full-width-at-half-maximum analysis indicated slightly broader penumbrae at 10 MV (∼+0.1 mm) and narrower in-plane penumbrae for FFF beams. Output factors ranged from ∼0.70 (5 × 5 mm<sup>2</sup>) to 1.00 (40 × 40 mm<sup>2</sup>). Mainly, microSilicon agreed more closely with film than microDiamond in the smallest fields.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"570 ","pages":"Article 165945"},"PeriodicalIF":1.4,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526837","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}
Mo L-shell x rays have been measured for the bombardment of highly charged heavy Ar11+ ions in the energy range of 1 MeV − 3 MeV. The new experimental data for individual L-subshell and total L-shell x-ray production cross sections were obtained and compared with the theoretical calculations of BEA, PWBA, ECPSSR, ECUSAR, and that of BEA modified by the Coulomb repulsion (CR) and effective nuclear charge (Zeff). The effect of multiple ionization in the atomic parameters was considered. The smaller the fluorescence yield of single ionization, the greater the enhancement of x-ray radiation caused by multiple ionization. On the whole, the BEA-Zeff-CR-MI simulations adopting appropriate multiple ionization atomic parameters are found to be in good agreement with the data.
在1 MeV−3 MeV的能量范围内，测量了高电荷重Ar11+离子轰击Mo l壳层 x 射线。得到了单个l -亚壳层和总l -壳层x射线产生截面的新实验数据，并与BEA、PWBA、ECPSSR、ECUSAR以及经库仑斥力（CR）和有效核电荷（Zeff）修饰的BEA的理论计算结果进行了比较。考虑了多重电离对原子参数的影响。单次电离的荧光产额越小，多次电离对x射线辐射的增强作用越大。总的来说，采用适当的多电离原子参数的BEA-Zeff-CR-MI模拟结果与实际数据吻合较好。
{"title":"Mo L-shell x-ray production cross section by heavy Ar11+ ions near the Bohr velocity","authors":"Jing Wei , Xianming Zhou , Rui Cheng , Changhui Liang , Yanning Zhang , Xiaoan Zhang , Yongtao Zhao","doi":"10.1016/j.nimb.2025.165944","DOIUrl":"10.1016/j.nimb.2025.165944","url":null,"abstract":"<div><div>Mo L-shell x rays have been measured for the bombardment of highly charged heavy Ar<sup>11+</sup> ions in the energy range of 1 MeV − 3 MeV. The new experimental data for individual L-subshell and total L-shell x-ray production cross sections were obtained and compared with the theoretical calculations of BEA, PWBA, ECPSSR, ECUSAR, and that of BEA modified by the Coulomb repulsion (CR) and effective nuclear charge (Z<sub>eff</sub>). The effect of multiple ionization in the atomic parameters was considered. The smaller the fluorescence yield of single ionization, the greater the enhancement of x-ray radiation caused by multiple ionization. On the whole, the BEA-Z<sub>eff</sub>-CR-MI simulations adopting appropriate multiple ionization atomic parameters are found to be in good agreement with the data.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"570 ","pages":"Article 165944"},"PeriodicalIF":1.4,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526838","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}
Pub Date : 2025-11-10DOI: 10.1016/j.nimb.2025.165935
Zuzana Slavkovská , Ferdos Dastgiri , L. Keith Fifield , Michaela B. Froehlich , Michael A.C. Hotchkis , Dominik Koll , Silke Merchel , Stefan Pavetich , Stephen G. Tims , Anton Wallner
Sodium iodide crystals doped with thallium NaI(Tl) can be used as detector material for direct dark matter detection by taking advantage of their particle detection properties of scintillation. In order to achieve this, it is crucial that these crystals are of ultra-high purity. Radioimpurities within the crystals may potentially mimic dark matter signals and thus must be quantified, minimised where possible and distinguished from real events. Abundances of radionuclides 129I and 210Pb, which are dominant sources of radioimpurities in NaI(Tl) crystals, were measured using accelerator mass spectrometry at the Australian National University (ANU) and the Australian Nuclear Science and Technology Organisation (ANSTO). NaI powder chemically processed to AgI, and, for the first time, unprocessed NaI powder, were shown to be suitable as AMS targets. A consistent 129I/127I ratio of (2.0 0.3) 10−13 was measured in three different commercially available NaI powders, one order of magnitude higher than the measured blank with (1.4 0.3) 10−14. Therefore, it was concluded that the choice of NaI powder has a negligible influence on the 129I contribution to low-background dark matter experiments. For 210Pb, different Pb molecular ion species were assessed with PbO being the preferred species and applied to investigate different lead oxide compounds for their suitability as Pb carriers. A 210Pb/Pb isotopic ratio of (3.6 ) 10−15 was measured in PbO powder. This met the required lower activity limit of 210Pb when adding 1 mg of stable lead into 1 kg of NaI(Tl) powder with a desired maximum 210Pb/Pb isotopic ratio of 1 10−14. These results indicate the suitability of the investigated PbO as a potential carrier for incorporation with Pb extracted from NaI used for dark matter experiments.
{"title":"Dark matter detector radioimpurities 129I and 210Pb measured with accelerator mass spectrometry","authors":"Zuzana Slavkovská , Ferdos Dastgiri , L. Keith Fifield , Michaela B. Froehlich , Michael A.C. Hotchkis , Dominik Koll , Silke Merchel , Stefan Pavetich , Stephen G. Tims , Anton Wallner","doi":"10.1016/j.nimb.2025.165935","DOIUrl":"10.1016/j.nimb.2025.165935","url":null,"abstract":"<div><div>Sodium iodide crystals doped with thallium NaI(Tl) can be used as detector material for direct dark matter detection by taking advantage of their particle detection properties of scintillation. In order to achieve this, it is crucial that these crystals are of ultra-high purity. Radioimpurities within the crystals may potentially mimic dark matter signals and thus must be quantified, minimised where possible and distinguished from real events. Abundances of radionuclides <sup>129</sup>I and <sup>210</sup>Pb, which are dominant sources of radioimpurities in NaI(Tl) crystals, were measured using accelerator mass spectrometry at the Australian National University (ANU) and the Australian Nuclear Science and Technology Organisation (ANSTO). NaI powder chemically processed to AgI, and, for the first time, unprocessed NaI powder, were shown to be suitable as AMS targets. A consistent <sup>129</sup>I/<sup>127</sup>I ratio of (2.0<!--> <span><math><mo>±</mo></math></span> 0.3)<!--> <span><math><mo>×</mo></math></span> <!--> <!-->10<sup>−13</sup> was measured in three different commercially available NaI powders, one order of magnitude higher than the measured blank with (1.4<!--> <span><math><mo>±</mo></math></span> 0.3)<!--> <span><math><mo>×</mo></math></span> <!--> <!-->10<sup>−14</sup>. Therefore, it was concluded that the choice of NaI powder has a negligible influence on the <sup>129</sup>I contribution to low-background dark matter experiments. For <sup>210</sup>Pb, different Pb molecular ion species were assessed with PbO<span><math><msubsup><mrow></mrow><mrow><mn>2</mn></mrow><mrow><mo>−</mo></mrow></msubsup></math></span> being the preferred species and applied to investigate different lead oxide compounds for their suitability as Pb carriers. A <sup>210</sup>Pb/Pb isotopic ratio of (3.6 <span><math><mo>±</mo></math></span> <span><math><msubsup><mrow></mrow><mrow><mn>1</mn><mo>.</mo><mn>4</mn></mrow><mrow><mn>1</mn><mo>.</mo><mn>7</mn></mrow></msubsup></math></span>)<!--> <span><math><mo>×</mo></math></span> <!--> <!-->10<sup>−15</sup> was measured in Pb<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> powder. This met the required lower activity limit of <sup>210</sup>Pb when adding 1<!--> <!-->mg of stable lead into 1<!--> <!-->kg of NaI(Tl) powder with a desired maximum <sup>210</sup>Pb/Pb isotopic ratio of 1<!--> <span><math><mo>×</mo></math></span> <!--> <!-->10<sup>−14</sup>. These results indicate the suitability of the investigated Pb<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> as a potential carrier for incorporation with Pb extracted from NaI used for dark matter experiments.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"570 ","pages":"Article 165935"},"PeriodicalIF":1.4,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526839","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}
Pub Date : 2025-11-10DOI: 10.1016/j.nimb.2025.165926
A.L.F. de Barros , C. Mejia , D.V. Doreste , A. Domaracka , P. Boduch , H. Rothard , E.F. da Silveira
Ices in interstellar and planetary environments are constantly altered by cosmic radiation. Using FTIR spectroscopy, we analyse radiation-induced changes in ices containing H2O, CO, CO2, and CH3OH, molecules abundant in the Solar System and interstellar medium. Molecular degradation is quantified by apparent cross-sections that scale with the electronic stopping power (Se). Literature data reveal a power-law dependence, σd ∝ Sen, influenced by thickness, sputtering yield, and radiochemical effects. This empirical relationship serves as a benchmark for assessing molecular stability and the interplay between sputtering and radiolysis, improving models of chemical evolution in astrophysical ices.
{"title":"Evaluation of the degradation cross-cection as stopping power dependence for pure and mixture molecular samples at cryogenic temperatures","authors":"A.L.F. de Barros , C. Mejia , D.V. Doreste , A. Domaracka , P. Boduch , H. Rothard , E.F. da Silveira","doi":"10.1016/j.nimb.2025.165926","DOIUrl":"10.1016/j.nimb.2025.165926","url":null,"abstract":"<div><div>Ices in interstellar and planetary environments are constantly altered by cosmic radiation. Using FTIR spectroscopy, we analyse radiation-induced changes in ices containing H<sub>2</sub>O, CO, CO<sub>2</sub>, and CH<sub>3</sub>OH,<!--> <!-->molecules abundant in the Solar System and interstellar medium. Molecular degradation is quantified by apparent cross-sections that scale with the electronic stopping power (S<sub>e</sub>). Literature data reveal a power-law dependence, σ<sub>d</sub> ∝ S<sub>e</sub><sup>n</sup>, influenced by thickness, sputtering yield, and radiochemical effects. This empirical relationship serves as a benchmark for assessing molecular stability and the interplay between sputtering and radiolysis, improving models of chemical evolution in astrophysical ices.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"570 ","pages":"Article 165926"},"PeriodicalIF":1.4,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526885","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}
Pub Date : 2025-11-10DOI: 10.1016/j.nimb.2025.165943
David D. Cohen
Recent developments in machine learning (ML) have enabled the creation of codes that train computers to predict elemental concentrations directly from raw IBA spectra. Once trained on spectra that span the expected elements and concentrations, these ML codes can then generate a wide range of elemental concentrations from individual raw spectra—without needing any input from physics models or detector characteristics. These methods bypass the need to use fundamental physics parameters such as ionisation cross sections, stopping powers, fluorescence yields, Coster-Kronig transitions, line emission rates together with a knowledge the detector efficiency, precise geometry, and accurate X-ray line resolution for energies from 1 to 20 keV.
Here, we reverse this ML approach by using it to predict raw PIXE spectra, channel by channel, from known elemental concentrations. We train ML codes with elemental data from Al to Pb and their associated raw PIXE spectra. The trained models then generate full raw PIXE spectra from any concentration set measured on thin stretched Teflon filters. This allows the spectrum simulation of a broad range of elemental concentrations from ng/cm2 to tens of percent and assess the detectability of overlapping or interfering trace elements.
{"title":"Synthesis of X-ray spectra (SOXS): Use of machine learning techniques to generate raw X-ray spectra from known elemental concentrations","authors":"David D. Cohen","doi":"10.1016/j.nimb.2025.165943","DOIUrl":"10.1016/j.nimb.2025.165943","url":null,"abstract":"<div><div>Recent developments in machine learning (ML) have enabled the creation of codes that train computers to predict elemental concentrations directly from raw IBA spectra. Once trained on spectra that span the expected elements and concentrations, these ML codes can then generate a wide range of elemental concentrations from individual raw spectra—without needing any input from physics models or detector characteristics. These methods bypass the need to use fundamental physics parameters such as ionisation cross sections, stopping powers, fluorescence yields, Coster-Kronig transitions, line emission rates together with a knowledge the detector efficiency, precise geometry, and accurate X-ray line resolution for energies from 1 to 20 keV.</div><div>Here, we reverse this ML approach by using it to predict raw PIXE spectra, channel by channel, from known elemental concentrations. We train ML codes with elemental data from Al to Pb and their associated raw PIXE spectra. The trained models then generate full raw PIXE spectra from any concentration set measured on thin stretched Teflon filters. This allows the spectrum simulation of a broad range of elemental concentrations from ng/cm<sup>2</sup> to tens of percent and assess the detectability of overlapping or interfering trace elements.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"570 ","pages":"Article 165943"},"PeriodicalIF":1.4,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526841","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}
Pub Date : 2025-11-10DOI: 10.1016/j.nimb.2025.165941
A.P. Chaynikov, A.G. Kochur, A.I. Dudenko
The reemission of energy by a platinum atom as a result of photoionization and subsequent cascade decay of vacancies is studied at incident photon energies of 0.01–1000 keV. The energy acquired by the Pt atom upon photoionization is split into the following channels: a) energy stored in final cascade ions, b) energy reemitted by cascade electrons, and c) energy reemitted by cascade photons. These quantities, as well as the average energy of photoelectrons, are calculated depending on the energy of the incident photons. Channel (a) is significant only in the UV and soft X-ray regions up to 2 keV. In the incident photon energy range from O2 to K ionization threshold, channel (b) dominates. Channel (c) prevails at photon energies above the K-threshold. When platinum-containing agents are used as radiosensitizers in radiation therapy of cancer, cascade electrons and photoelectrons are shown to be principal depositors of energy to the tumor.
{"title":"Energy reemission by the platinum atom irradiated by photons in 0.01–1000 keV energy range","authors":"A.P. Chaynikov, A.G. Kochur, A.I. Dudenko","doi":"10.1016/j.nimb.2025.165941","DOIUrl":"10.1016/j.nimb.2025.165941","url":null,"abstract":"<div><div>The reemission of energy by a platinum atom as a result of photoionization and subsequent cascade decay of vacancies is studied at incident photon energies of 0.01–1000 <!--> <!-->keV. The energy acquired by the Pt atom upon photoionization is split into the following channels: a) energy stored in final cascade ions, b) energy reemitted by cascade electrons, and c) energy reemitted by cascade photons. These quantities, as well as the average energy of photoelectrons, are calculated depending on the energy of the incident photons. Channel (a) is significant only in the UV and soft X-ray regions up to 2 <!--> <!-->keV. In the incident photon energy range from <em>O</em><sub>2</sub> to <em>K</em> ionization threshold, channel (b) dominates. Channel (c) prevails at photon energies above the <em>K</em>-threshold. When platinum-containing agents are used as radiosensitizers in radiation therapy of cancer, cascade electrons and photoelectrons are shown to be principal depositors of energy to the tumor.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"570 ","pages":"Article 165941"},"PeriodicalIF":1.4,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526840","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}
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