Pub Date : 2026-01-09DOI: 10.1016/j.nimb.2025.165997
M. Hadj Ali , S. Mokrani , H. Aouchiche , C. Champion
We here performed the calculation of differential and integral cross sections of electron elastically scattered by bimolecular targets found in the nucleic bases constituting DNA and RNA, namely, pyrimidine and uracil. The calculation model is based on a corrected Independent Atom Model (IAM) model that takes into account various potentials at short and long ranges (static potential, correlation-polarization and exchange potentials) as well as multiple-scattering effects like the 1st and 2nd order of interferences between single and double scattering and that of purely double scattering. The impact energies investigated here in terms of differential cross sections are 50 eV, 70 eV, 80 eV, 100 eV, 300 eV, 400 eV, 800 eV, 1000 eV and 10 000 eV, with scattering angles ranging from 0◦ to 180◦. In addition, integral elastic scattering cross sections are also calculated for both biomolecules for incident energies ranging from 20 eV to 100 keV. All results obtained are compared to experimental data as well as theoretical predictions available in the literature. General good agreements are found.
{"title":"Differential and integral cross sections for electron elastic scattering by pyrimidine and uracil biomolecules","authors":"M. Hadj Ali , S. Mokrani , H. Aouchiche , C. Champion","doi":"10.1016/j.nimb.2025.165997","DOIUrl":"10.1016/j.nimb.2025.165997","url":null,"abstract":"<div><div>We here performed the calculation of differential and integral cross sections of electron elastically scattered by bimolecular targets found in the nucleic bases constituting DNA and RNA, namely, pyrimidine and uracil. The calculation model is based on a corrected Independent Atom Model (IAM) model that takes into account various potentials at short and long ranges (static potential, correlation-polarization and exchange potentials) as well as multiple-scattering effects like the 1st and 2nd order of interferences between single and double scattering and that of purely double scattering. The impact energies investigated here in terms of differential cross sections are 50 eV, 70 eV, 80 eV, 100 eV, 300 eV, 400 eV, 800 eV, 1000 eV and 10 000 eV, with scattering angles ranging from 0<sup>◦</sup> to 180<sup>◦</sup>. In addition, integral elastic scattering cross sections are also calculated for both biomolecules for incident energies ranging from 20 eV to 100 keV. All results obtained are compared to experimental data as well as theoretical predictions available in the literature. General good agreements are found.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"572 ","pages":"Article 165997"},"PeriodicalIF":1.4,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939863","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}
The measurement of ionization cross-sections using the thick-target method involves ill-posed inverse problems, with performance varying across techniques. In this study, the DWBA cross-section is used as the assumed true value, based on PENELOPE simulations of the Kɑβ and Mɑβ characteristic X-ray yields induced by positron collisions with pure thick Al and Bi targets below 9 keV, as well as the Kɑβ and Lɑβγ characteristic X-ray yields induced by electron collisions with pure thick Ti and W targets below 28 keV. Three methods—Tikhonov regularization, numerical-neural network, and MC-neural network—are applied to invert the cross-sections, with their accuracy evaluated. A method for quantitatively assessing stability based on MC yield errors is also proposed. Results show that the numerical-neural network achieves the best accuracy and stability, while the MC-neural network performs slightly worse due to limited training data, and the regularization method exhibits larger errors and lower stability in certain energy ranges. The methods are also applied to experimental yields of Ti Kαβ and W Lαβ induced by electrons below 27 keV, further confirming the reliability of neural network methods for solving inverse problems.
{"title":"A comparative study on the accuracy and stability of different inversion methods for deriving atomic inner-shell ionization cross-sections from characteristic X-ray yields produced by near-threshold lepton collisions with thick targets","authors":"Jiaolong Wu, Ying Wu, Kun He, Yifei Guo, Zhiwen Li, Xiaogang Sheng","doi":"10.1016/j.nimb.2025.165923","DOIUrl":"10.1016/j.nimb.2025.165923","url":null,"abstract":"<div><div>The measurement of ionization cross-sections using the thick-target method involves ill-posed inverse problems, with performance varying across techniques. In this study, the DWBA cross-section is used as the assumed true value, based on PENELOPE simulations of the K<sub>ɑβ</sub> and M<sub>ɑβ</sub> characteristic X-ray yields induced by positron collisions with pure thick Al and Bi targets below 9 keV, as well as the K<sub>ɑβ</sub> and L<sub>ɑβγ</sub> characteristic X-ray yields induced by electron collisions with pure thick Ti and W targets below 28 keV. Three methods—Tikhonov regularization, numerical-neural network, and MC-neural network—are applied to invert the cross-sections, with their accuracy evaluated. A method for quantitatively assessing stability based on MC yield errors is also proposed. Results show that the numerical-neural network achieves the best accuracy and stability, while the MC-neural network performs slightly worse due to limited training data, and the regularization method exhibits larger errors and lower stability in certain energy ranges. The methods are also applied to experimental yields of Ti K<sub>αβ</sub> and W L<sub>αβ</sub> induced by electrons below 27 keV, further confirming the reliability of neural network methods for solving inverse problems.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"572 ","pages":"Article 165923"},"PeriodicalIF":1.4,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090555","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 : 2026-01-08DOI: 10.1016/j.nimb.2025.165991
Asar A.H. Jaradat , Reinhard Heinke , Bruce A. Marsh , Dominik Studer , Kara M. Lynch , Kieran T. Flanagan , Klaus Wendt , Matou Stemmler , Sebastian Raeder , Sebastian Rothe , Simone Gilardoni , Thorben Niemeyer , Raphael Hasse
A Monte-Carlo-type simulation model has been developed to describe the effusion of atoms from hot cavity tubes for application to high-purity laser resonance ionization ion sources. The model is validated by comparison with theoretical descriptions of low-pressure particle transfer mechanisms and experimental data obtained by probing the spatial evolution of the atom density downstream for different atom source geometries with laser ionization. The numeric studies, in agreement with the experimental validation, quantify possible efficiency improvements in the order of 30% for high-purity resonance ionization laser ion sources, and highlight the significance of closest distance between atom source and active ionization region. The developed simulation model is a stepping stone for further investigations into efficiency, experimental resolution for laser spectroscopy applications, and more sophisticated geometries.
{"title":"Simulation and experimental validation of atom effusion characteristics for resonance ionization laser ion source geometries","authors":"Asar A.H. Jaradat , Reinhard Heinke , Bruce A. Marsh , Dominik Studer , Kara M. Lynch , Kieran T. Flanagan , Klaus Wendt , Matou Stemmler , Sebastian Raeder , Sebastian Rothe , Simone Gilardoni , Thorben Niemeyer , Raphael Hasse","doi":"10.1016/j.nimb.2025.165991","DOIUrl":"10.1016/j.nimb.2025.165991","url":null,"abstract":"<div><div>A Monte-Carlo-type simulation model has been developed to describe the effusion of atoms from hot cavity tubes for application to high-purity laser resonance ionization ion sources. The model is validated by comparison with theoretical descriptions of low-pressure particle transfer mechanisms and experimental data obtained by probing the spatial evolution of the atom density downstream for different atom source geometries with laser ionization. The numeric studies, in agreement with the experimental validation, quantify possible efficiency improvements in the order of 30% for high-purity resonance ionization laser ion sources, and highlight the significance of closest distance between atom source and active ionization region. The developed simulation model is a stepping stone for further investigations into efficiency, experimental resolution for laser spectroscopy applications, and more sophisticated geometries.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"572 ","pages":"Article 165991"},"PeriodicalIF":1.4,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939922","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 : 2026-01-08DOI: 10.1016/j.nimb.2026.166002
Ning Chen , Weijian Zhou , Yukun Fan , Feng Xian , Luyuan Zhang , Yanyun Wang , Qi Liu , Xiaolin Hou
129I serves as an effective tracer for reconstructing 131I derived from nuclear accident. Precipitation samples collected in Xi’an, China, in 2011 were analyzed for iodine isotopes. The concentration of 129I ranged from 1.0 × 107 atoms/L to 81.8 × 107 atoms/L, with an average of 10.3 × 107 atoms/L. The 129I/127I atomic ratio ranged from 0.64 × 10-9 to 26.73 × 10-9, with an average of 4.47 × 10-9. Compared with pre-accident precipitation samples from Xi’an and other local samples in 2009, no obvious elevation in 129I/127I ratio was observed after the Fukushima accident. These results suggest a relatively minor impact of the Fukushima nuclear accident on iodine isotopes in Xi’an.
{"title":"129I in precipitation from Xi’an, China in 2011: Influence of the Fukushima nuclear accident","authors":"Ning Chen , Weijian Zhou , Yukun Fan , Feng Xian , Luyuan Zhang , Yanyun Wang , Qi Liu , Xiaolin Hou","doi":"10.1016/j.nimb.2026.166002","DOIUrl":"10.1016/j.nimb.2026.166002","url":null,"abstract":"<div><div><sup>129</sup>I serves as an effective tracer for reconstructing <sup>131</sup>I derived from nuclear accident. Precipitation samples collected in Xi’an, China, in 2011 were analyzed for iodine isotopes. The concentration of <sup>129</sup>I ranged from 1.0 × 10<sup>7</sup> atoms/L to 81.8 × 10<sup>7</sup> atoms/L, with an average of 10.3 × 10<sup>7</sup> atoms/L. The <sup>129</sup>I/<sup>127</sup>I atomic ratio ranged from 0.64 × 10<sup>-9</sup> to 26.73 × 10<sup>-9</sup>, with an average of 4.47 × 10<sup>-9</sup>. Compared with pre-accident precipitation samples from Xi’an and other local samples in 2009, no obvious elevation in <sup>129</sup>I/<sup>127</sup>I ratio was observed after the Fukushima accident.<!--> <!-->These results suggest a relatively minor impact of the Fukushima nuclear accident on iodine isotopes in Xi’an.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"572 ","pages":"Article 166002"},"PeriodicalIF":1.4,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939923","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 : 2026-01-07DOI: 10.1016/j.nimb.2026.166000
Huaqing Huang , Yingjie Song , Chuanwei Dai , Bolong Wang , Rui Jia , Yunbiao Zhao , Jianming Xue
Silicon radiation detectors are vital in nuclear physics research experiments and numerous industrial applications. Among them, Schottky-type detectors (STDs) are particularly favored for high-energy radiation detection due to their inherent linearity and fast response. However, the radiation-induced damage mechanisms in STDs, especially those incorporating Al2O3 insulator passivation, remain poorly understood, hindering their reliability in harsh environments. This work systematically investigates the effects of 3 MeV proton irradiation on novel Pt/Al2O3/Si passivated STDs using in-situ electrical characterization. Upon proton irradiation, the detectors exhibit a distinct degradation process with increasing radiation fluence of 1.1 × 1014 cm−2, characterized by a substantial increase in reverse leakage current and a decrease in forward current. These changes are attributed to two primary mechanisms: radiation-induced interface state at the Al2O3/Si interface, lowering the Schottky barrier height from 0.87 eV to 0.73 eV, and bulk displacement damage causing increased generation-recombination current and carrier removal effects. Furthermore, we demonstrate that room-temperature annealing leads to partial recovery of detector performance. These findings provide critical insights into radiation hardness of passivated Schottky detectors for applications in high-energy physics, space exploration, and radiation monitoring environments.
{"title":"Unraveling Proton-Induced degradation mechanisms in Al2O3-Passivated Schottky detectors","authors":"Huaqing Huang , Yingjie Song , Chuanwei Dai , Bolong Wang , Rui Jia , Yunbiao Zhao , Jianming Xue","doi":"10.1016/j.nimb.2026.166000","DOIUrl":"10.1016/j.nimb.2026.166000","url":null,"abstract":"<div><div>Silicon radiation detectors are vital in nuclear physics research experiments and numerous industrial applications. Among them, Schottky-type detectors (STDs) are particularly favored for high-energy radiation detection due to their inherent linearity and fast response. However, the radiation-induced damage mechanisms in STDs, especially those incorporating Al<sub>2</sub>O<sub>3</sub> insulator passivation, remain poorly understood, hindering their reliability in harsh environments. This work systematically investigates the effects of 3 MeV proton irradiation on novel Pt/Al<sub>2</sub>O<sub>3</sub>/Si passivated STDs using in-situ electrical characterization. Upon proton irradiation, the detectors exhibit a distinct degradation process with increasing radiation fluence of 1.1 × 10<sup>14</sup> cm<sup>−2</sup>, characterized by a substantial increase in reverse leakage current and a decrease in forward current. These changes are attributed to two primary mechanisms: radiation-induced interface state at the Al<sub>2</sub>O<sub>3</sub>/Si interface, lowering the Schottky barrier height from 0.87 eV to 0.73 eV, and bulk displacement damage causing increased generation-recombination current and carrier removal effects. Furthermore, we demonstrate that room-temperature annealing leads to partial recovery of detector performance. These findings provide critical insights into radiation hardness of passivated Schottky detectors for applications in high-energy physics, space exploration, and radiation monitoring environments.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"572 ","pages":"Article 166000"},"PeriodicalIF":1.4,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939561","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}
Deuterium-tritium fusion reactions release a significant amount of energy and offer advantages in terms of cleanliness, safety, and efficiency. As such, they are considered promising candidates for the ultimate energy source for future human civilization. Tungsten is regarded as a plasma-facing material and inevitably experiences irradiation by helium (He) plasma. Furthermore, He can also be generated through transmutation reactions in W under neutron irradiation. Helium exerts a detrimental influence on the service performance of tungsten-based materials, particularly with respect to their mechanical properties. As the primary transmutation product, rhenium (Re) is expected to interact strongly with helium. In this study, high-energy He ions were employed to irradiate W and W-5Re alloys to investigate their surface morphology and internal microstructural evolution. The experimental results show that the presence of Re can mitigate surface blistering, inhibit He diffusion into the bulk material, and simultaneously suppress the growth of internal He bubbles.
{"title":"Comparative study of surface modification and internal helium bubble evolution in tungsten and tungsten-5% rhenium under helium ion implantation","authors":"Tongjun Xia, Qiubo Hu, Chunjuan Tang, Feng Shan, Jia Liu, Xuetong Guo, Longyu Liu, Zhijian Chang, Haozhe Wu, Shusheng Zhang","doi":"10.1016/j.nimb.2026.166001","DOIUrl":"10.1016/j.nimb.2026.166001","url":null,"abstract":"<div><div>Deuterium-tritium fusion reactions release a significant amount of energy and offer advantages in terms of cleanliness, safety, and efficiency. As such, they are considered promising candidates for the ultimate energy source for future human civilization. Tungsten is regarded as a plasma-facing material and inevitably experiences irradiation by helium (He) plasma. Furthermore, He can also be generated through transmutation reactions in W under neutron irradiation. Helium exerts a detrimental influence on the service performance of tungsten-based materials, particularly with respect to their mechanical properties. As the primary transmutation product, rhenium (Re) is expected to interact strongly with helium. In this study, high-energy He ions were employed to irradiate W and W-5Re alloys to investigate their surface morphology and internal microstructural evolution. The experimental results show that the presence of Re can mitigate surface blistering, inhibit He diffusion into the bulk material, and simultaneously suppress the growth of internal He bubbles.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"572 ","pages":"Article 166001"},"PeriodicalIF":1.4,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885283","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 : 2026-01-02DOI: 10.1016/j.nimb.2025.165992
Yuzhi Zhao , Linan Ma , Yang Tan
Ion irradiation and precise diamond blade dicing are widely used techniques for fabricating planar and geometrically shaped optical waveguides, respectively. We demonstrate a hybrid method combining carbon (C) ion irradiation with precise diamond blade dicing to create a channel waveguide in an Yb:YSGG crystal. The planar waveguide was fabricated by irradiation with 6 MeV and 15 MeV C ions. Subsequently, the planar structure was precision-cut using a diamond dicing blade to form a 50 µm-wide channel waveguide. The fabricated channel waveguide exhibits polarization-dependent guiding properties at 633 nm, showing lower TE-polarization insertion loss. A 1 µm Q-switched pulsed laser was realized utilizing a WS2 saturable absorber deposited on the waveguide surface. Under TE-polarized pumping, the laser achieved 92.3 ns minimum pulse width and 2.4 MHz maximum repetition rate. This work highlights the versatility of ion irradiation in optical waveguide fabrication and its potential for developing compact, high-performance integrated photonic devices.
{"title":"C ion irradiated and diamond blade diced Yb:YSGG channel waveguide for Q-switched pulsed laser generation","authors":"Yuzhi Zhao , Linan Ma , Yang Tan","doi":"10.1016/j.nimb.2025.165992","DOIUrl":"10.1016/j.nimb.2025.165992","url":null,"abstract":"<div><div>Ion irradiation and precise diamond blade dicing are widely used techniques for fabricating planar and geometrically shaped optical waveguides, respectively. We demonstrate a hybrid method combining carbon (C) ion irradiation with precise diamond blade dicing to create a channel waveguide in an Yb:YSGG crystal. The planar waveguide was fabricated by irradiation with 6 MeV and 15 MeV C ions. Subsequently, the planar structure was precision-cut using a diamond dicing blade to form a 50 µm-wide channel waveguide. The fabricated channel waveguide exhibits polarization-dependent guiding properties at 633 nm, showing lower TE-polarization insertion loss. A 1 µm Q-switched pulsed laser was realized utilizing a WS<sub>2</sub> saturable absorber deposited on the waveguide surface. Under TE-polarized pumping, the laser achieved 92.3 ns minimum pulse width and 2.4 MHz maximum repetition rate. This work highlights the versatility of ion irradiation in optical waveguide fabrication and its potential for developing compact, high-performance integrated photonic devices.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"572 ","pages":"Article 165992"},"PeriodicalIF":1.4,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885284","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 : 2026-01-01DOI: 10.1016/j.nimb.2025.165995
Linan Wang , Jun Zhong , Mao-Liang Zhang , Guo-Ming Liu , Sheng Xu
Volcanic degassing is a critical natural carbon source to the atmosphere, with significant implications for global carbon cycling and climate dynamics. The assimilation of 14C-depleted deep carbon by vegetation provides a biological proxy for deep carbon emissions. In this study, we investigated the carbon isotopic compositions (δ13C and Δ14C) of annual herbaceous plants from the geothermal areas in the Changbaishan volcanic area to assess their potential as proxies for monitoring deep carbon emissions. Our results revealed pronounced isotopic anomalies in plants from geothermal areas, with δ13C values ranging from −31.5 ‰ to −26.4 ‰ and Δ14C spanning −590 ‰ to +9 ‰, indicating significant dilution by 14C-free deep carbon. The Jinjiang geothermal area exhibited the lowest Δ14C value (−590 ‰), reflecting localized hyperactive degassing. The observed carbon isotopic compositions were primarily influenced by deep carbon emissions, with additional effects from interspecific metabolic fractionation among plant species. We estimated deep CO2 concentrations at the sampling sites and observed a clear trend of increasing deep CO2 concentrations closer to emission sources (hot springs). Anomalously elevated deep carbon signals at distal sites (e.g., JL1) were correlated with root-mediated uptake of dissolved deep CO2, as evidenced by isotopic disparities in riparian plants. This study highlighted the feasibility of using annual herbaceous plants as alternative biological proxies for monitoring deep carbon emissions, offering a novel methodology for tracking volcanic activity.
{"title":"Plant radiocarbon (14C) as a biological proxy for deep carbon emissions in the Changbaishan volcanic area","authors":"Linan Wang , Jun Zhong , Mao-Liang Zhang , Guo-Ming Liu , Sheng Xu","doi":"10.1016/j.nimb.2025.165995","DOIUrl":"10.1016/j.nimb.2025.165995","url":null,"abstract":"<div><div>Volcanic degassing is a critical natural carbon source to the atmosphere, with significant implications for global carbon cycling and climate dynamics. The assimilation of <sup>14</sup>C-depleted deep carbon by vegetation provides a biological proxy for deep carbon emissions. In this study, we investigated the carbon isotopic compositions (δ<sup>13</sup>C and Δ<sup>14</sup>C) of annual herbaceous plants from the geothermal areas in the Changbaishan volcanic area to assess their potential as proxies for monitoring deep carbon emissions. Our results revealed pronounced isotopic anomalies in plants from geothermal areas, with δ<sup>13</sup>C values ranging from −31.5 ‰ to −26.4 ‰ and Δ<sup>14</sup>C spanning −590 ‰ to +9 ‰, indicating significant dilution by <sup>14</sup>C-free deep carbon. The Jinjiang geothermal area exhibited the lowest Δ<sup>14</sup>C value (−590 ‰), reflecting localized hyperactive degassing. The observed carbon isotopic compositions were primarily influenced by deep carbon emissions, with additional effects from interspecific metabolic fractionation among plant species. We estimated deep CO<sub>2</sub> concentrations at the sampling sites and observed a clear trend of increasing deep CO<sub>2</sub> concentrations closer to emission sources (hot springs). Anomalously elevated deep carbon signals at distal sites (e.g., JL1) were correlated with root-mediated uptake of dissolved deep CO<sub>2</sub>, as evidenced by isotopic disparities in riparian plants. This study highlighted the feasibility of using annual herbaceous plants as alternative biological proxies for monitoring deep carbon emissions, offering a novel methodology for tracking volcanic activity.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"572 ","pages":"Article 165995"},"PeriodicalIF":1.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885285","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 : 2025-12-31DOI: 10.1016/j.nimb.2025.165996
Wangxuan Li , Huanling Liu , Shengli Wang , Deming Li , Yuhua Ma
This study presents the development of a Positive ion source Accelerator Mass Spectrometry (PAMS) system in Shanghai Institute of Applied Physics (SINAP) with an extraction voltage of 30 kV, aiming to improve the convenience of radiocarbon analysis and provide an alternative approach for the measurement of radiocarbon in environmental samples and biological samples. In this work, we primarily demonstrate the technical design of PAMS and the progress in related commissioning, including beam optics calculations, ECR ion source testing, and the design optimization of electromagnetic components and charge exchange cell. The results obtained will provide theoretical and technical support for device commissioning and experimental research.
{"title":"Technical design of a new facility: Positive ion source Accelerator Mass Spectrometry","authors":"Wangxuan Li , Huanling Liu , Shengli Wang , Deming Li , Yuhua Ma","doi":"10.1016/j.nimb.2025.165996","DOIUrl":"10.1016/j.nimb.2025.165996","url":null,"abstract":"<div><div>This study presents the development of a Positive ion source Accelerator Mass Spectrometry (PAMS) system in Shanghai Institute of Applied Physics (SINAP) with an extraction voltage of 30 kV, aiming to improve the convenience of radiocarbon analysis and provide an alternative approach for the measurement of radiocarbon in environmental samples and biological samples. In this work, we primarily demonstrate the technical design of PAMS and the progress in related commissioning, including beam optics calculations, ECR ion source testing, and the design optimization of electromagnetic components and charge exchange cell. The results obtained will provide theoretical and technical support for device commissioning and experimental research.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"572 ","pages":"Article 165996"},"PeriodicalIF":1.4,"publicationDate":"2025-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885281","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 : 2025-12-31DOI: 10.1016/j.nimb.2025.165993
Melania Beatrice Istrati , Mihaela Enachescu , Alexandru Razvan Petre , Paul Emil Mereuta
The increasingly wide range of human activities in the nuclear field, such as nuclear weapons technologies, nuclear reactors for energy production, spent nuclear fuel reprocessing plants and nuclear waste repositories has increased the importance of monitoring and preventing nuclear pollution.
In the early stages of nuclear pollution, the quantities of dispersed radioactive material in the environment can be extremely small, undetectable by most nuclear monitoring techniques. However, the accelerator mass spectrometry technique using 129I is suitable for detecting very small increases in nuclear pollution even during early stages when contamination levels are not yet hazardous.
In this research, we continue our work of determining 129I concentrations by analyzing water samples collected from across the entire territory of Romania [1], [2]. The aim is to map the current level of 129I concentration in order to assess the potential impact of future nuclear contaminations at the Romanian and Southeast European levels. The results obtained will complete the global map of 129I distribution created by Xuegao Chen et al. in 2015, which currently lacks data concerning Romania [3].
{"title":"The distribution of the 129I radioisotope concentration in surface waters across Romania","authors":"Melania Beatrice Istrati , Mihaela Enachescu , Alexandru Razvan Petre , Paul Emil Mereuta","doi":"10.1016/j.nimb.2025.165993","DOIUrl":"10.1016/j.nimb.2025.165993","url":null,"abstract":"<div><div>The increasingly wide range of human activities in the nuclear field, such as nuclear weapons technologies, nuclear reactors for energy production, spent nuclear fuel reprocessing plants and nuclear waste repositories has increased the importance of monitoring and preventing nuclear pollution.</div><div>In the early stages of nuclear pollution, the quantities of dispersed radioactive material in the environment can be extremely small, undetectable by most nuclear monitoring techniques. However, the accelerator mass spectrometry technique using <sup>129</sup>I is suitable for detecting very small increases in nuclear pollution even during early stages when contamination levels are not yet hazardous.</div><div>In this research, we continue our work of determining <sup>129</sup>I concentrations by analyzing water samples collected from across the entire territory of Romania <span><span>[1]</span></span>, <span><span>[2]</span></span>. The aim is to map the current level of <sup>129</sup>I concentration in order to assess the potential impact of future nuclear contaminations at the Romanian and Southeast European levels. The results obtained will complete the global map of <sup>129</sup>I distribution created by Xuegao Chen et al. in 2015, which currently lacks data concerning Romania <span><span>[3]</span></span>.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"572 ","pages":"Article 165993"},"PeriodicalIF":1.4,"publicationDate":"2025-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885282","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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