By combining experimental α-decay energies and half-lives, the α-particle preformation factor for nuclei around neutron magic numbers N of 126, 152, and 162 were extracted using the two-potential approach. The nucle...By combining experimental α-decay energies and half-lives, the α-particle preformation factor for nuclei around neutron magic numbers N of 126, 152, and 162 were extracted using the two-potential approach. The nuclei around the shell closure were more tightly bound than adjacent nuclei. Additionally, based on the WS4 mass model (Wang et al., Phys. Lett.B 734, 215 (2014)), we extended the two-potential approach to predict the α-decay half-lives of nuclei around N values of178 and 184 with Z of 119 and 120. We believe that our findings will serve as guidelines for future experimental studies.展开更多
We present new data on the^(63)Cu(γ,n)cross-section studied using a quasi-monochromatic and energy-tunableγbeam produced at the Shanghai Laser Electron Gamma Source to resolve the long-standing discrepancy between e...We present new data on the^(63)Cu(γ,n)cross-section studied using a quasi-monochromatic and energy-tunableγbeam produced at the Shanghai Laser Electron Gamma Source to resolve the long-standing discrepancy between existing measurements and evaluations of this cross-section.Using an unfolding iteration method,^(63)Cu(γ,n)data were obtained with an uncertainty of less than 4%,and the inconsistencies between the available experimental data were discussed.Theγ-ray strength function of^(63)Cu(γ,n)was successfully extracted as an experimental constraint.We further calculated the cross-section of the radiative neutron capture reaction^(62)Cu(n,γ)using the TALYS code.Our calculation method enables the extraction of(n,γ)cross-sections for unstable nuclides.展开更多
In this study,an end-to-end deep learning method is proposed to improve the accuracy of continuum estimation in low-resolution gamma-ray spectra.A novel process for generating the theoretical continuum of a simulated ...In this study,an end-to-end deep learning method is proposed to improve the accuracy of continuum estimation in low-resolution gamma-ray spectra.A novel process for generating the theoretical continuum of a simulated spectrum is established,and a convolutional neural network consisting of 51 layers and more than 105 parameters is constructed to directly predict the entire continuum from the extracted global spectrum features.For testing,an in-house NaI-type whole-body counter is used,and 106 training spectrum samples(20%of which are reserved for testing)are generated using Monte Carlo simulations.In addition,the existing fitting,step-type,and peak erosion methods are selected for comparison.The proposed method exhibits excellent performance,as evidenced by its activity error distribution and the smallest mean activity error of 1.5%among the evaluated methods.Additionally,a validation experiment is performed using a whole-body counter to analyze a human physical phantom containing four radionuclides.The largest activity error of the proposed method is−5.1%,which is considerably smaller than those of the comparative methods,confirming the test results.The multiscale feature extraction and nonlinear relation modeling in the proposed method establish a novel approach for accurate and convenient continuum estimation in a low-resolution gamma-ray spectrum.Thus,the proposed method is promising for accurate quantitative radioactivity analysis in practical applications.展开更多
Theβ-decay properties of^(67-80)As nuclei have been investigated within the framework of the proton-neutron quasi-particle random phase approximation(pn-QRPA)model.The nuclear deformation obtained from the finite ran...Theβ-decay properties of^(67-80)As nuclei have been investigated within the framework of the proton-neutron quasi-particle random phase approximation(pn-QRPA)model.The nuclear deformation obtained from the finite range droplet model is used as an input parameter in the pn-QRPA model for the analysis ofβ-decay properties including Gamow-Teller strength distributions,log ft,β-decay half-lives and stellarβ^(±)decay rates.The predicted log ft values were fairly consistent with the observed data.The computedβ-decay half-lives matched the measured values by a factor of 10.The stellar rates were compared with the shell model outcomes.At high densities and temperatures,theβ^(+)and electron capture rates had a finite contribution.However,theβ^(-)and positron capture rates are only significant at high temperatures and low densities.The pn-QRPA rates outperformed the shell model rates by a factor of 22 or more.展开更多
In this study,we explore the impact of state-of-the-art laser fields on theαdecay half-life of deformed ground-state odd-A nuclei within the proton number range of 52–107.The calculations show that the presence of a...In this study,we explore the impact of state-of-the-art laser fields on theαdecay half-life of deformed ground-state odd-A nuclei within the proton number range of 52–107.The calculations show that the presence of a laser field modulates theαdecay half-life by altering theαdecay penetration probability within a limited range.Moreover,the variance in the penetration probability rate of change between even–odd and odd–even nuclei is investigated.Furthermore,we investigate the rate of change of the penetration probability for the same parent nucleus with different neutron numbers,based on the characteristics of the odd-A nucleus.We found that the influence of the laser field on the penetration probability is determined by both the shell effect and odd–even staggering.This research contributes to the understanding of nuanced interactions between laser fields and nuclear decay processes.Therefore,valuable insights for future experiments in laser–nuclear physics are attainable using this study.展开更多
We employed Monte Carlo simulations via Geant4 to model the interactions of^(60)Co gamma rays(1.25 MeV),electrons(0.1-10 MeV),and protons(0.5-10 MeV)with Ta_(2)O_(5)optical coatings.By analyzing secondary electron gen...We employed Monte Carlo simulations via Geant4 to model the interactions of^(60)Co gamma rays(1.25 MeV),electrons(0.1-10 MeV),and protons(0.5-10 MeV)with Ta_(2)O_(5)optical coatings.By analyzing secondary electron generation and energy deposition,we found that 1.0 MeV electrons and protons produce 67.5 and 67 secondary electrons per particle,respectively,compared to 116 from 1.25 MeV gamma rays in thick targets.Boltzmann-function fitting revealed depth-dependent ionization equivalence:0.582 gamma photons match the secondary electron yield of a 1.0 MeV electron,and 0.577 gamma photons match a 1.0 MeV proton.These results establish a framework to convert ground-based gamma-ray test data to space environment scenarios,accounting for critical differences in penetration depth-protons deposit energy within 10μm(coating layers),while gamma rays penetrate>100 mm into substrates.This provides a theoretical basis for evaluating radiation effects using existing^(60)Co facilities,enabling reliable predictions of optical component durability in complex space environments.展开更多
The development of low-cost and highly efficient thermal neutron detection materials to substitute the rare and expensive^(3)He gas is important for applications requiring thermal neutron detection.Lithium-based glass...The development of low-cost and highly efficient thermal neutron detection materials to substitute the rare and expensive^(3)He gas is important for applications requiring thermal neutron detection.Lithium-based glass(Li glass)is a promising candidate due to its simple fabrication process and low cost.This paper reports the optical properties and scintillation performance of a new Ce^(3+)-doped Li glass,whose luminescence efficiency is significantly enhanced with a light yield of about 4770 ph/MeV,which is about 54%of that of BGO crystal,and the energy resolution is 14.5%for 662 keV gamma rays.The Ce^(3+)-doped Li glass shows a high light yield of about 7058 ph/neutron,which is about 1.18 times that of the reference GS20 glass.The Ce^(3+)-doped Li glass exhibits stronger gamma ray suppression capability compared to GS20 glass samples.Further optimizing the Ce^(3+)concentration and 6Li content is expected to achieve much superior neutron detection efficiency,positioning it as a promising alternative to^(3)He gas for efficient thermal neutron detection.展开更多
Nuclearβ-decay,a typical decay process for unstable nuclei,is a key mechanism for producing heavy elements in the Universe.In this study,neural networks were employed to predictβ-decay half-lives and,for the first t...Nuclearβ-decay,a typical decay process for unstable nuclei,is a key mechanism for producing heavy elements in the Universe.In this study,neural networks were employed to predictβ-decay half-lives and,for the first time,to identify abnormal trends in nuclearβ-decay half-lives based on deviations between experimental values and the predictions of neural networks.Nuclei exhibiting anomalous increases,abrupt peaks,sharp decreases,abnormal odd-even oscillations,and excessively large experimental errors in theirβ-decay half-lives,which deviate from systematic patterns,were identified through deviations.These anomalous phenomena may be associated with shell effects,shape coexistence,or discrepancies in the experimental data.The discovery and analysis of these abnormal nuclei provide a valuable reference for further investigations using sophisticated microscopic theories,potentially offering insights into new physics through studies of nuclearβ-decay half-lives.展开更多
Neutron-induced gamma-ray imaging is a spectroscopic technique that uses characteristic gamma rays to infer the elemental distribution of an object.Currently,this technique requires the use of large facilities to supp...Neutron-induced gamma-ray imaging is a spectroscopic technique that uses characteristic gamma rays to infer the elemental distribution of an object.Currently,this technique requires the use of large facilities to supply a high neutron flux and a time-consuming detection procedure involving direct collimating measurements.In this study,a new method based on low neutron flux was proposed.A single-pixel gamma-ray detector combined with random pattern gamma-ray masks was used to measure the characteristic gamma rays emitted from the sample.Images of the elemental distribution in the sample,comprising 30×30 pixels,were reconstructed using the maximum-likelihood expectation-maximization algorithm.The results demonstrate that the elemental imaging of the sample can be accurately determined using this method.The proposed approach,which eliminates the need for high neutron flux and scanning measurements,can be used for in-field imaging applications.展开更多
基金supported in part by the National Natural Science Foundation of China(Nos.12175100 and 11975132)Construct Program of the Key Discipline in Hunan Province,Research Foundation of Education Bureau of Hunan Province,China(Nos.21B0402,18A237 and 22A0305)+3 种基金Natural Science Foundation of Hunan Province,China(No.2018JJ2321)Innovation Group of Nuclear and Particle Physics in USC,Shandong Province Natural Science Foundation,China(No.ZR2022JQ04)Opening Project of Cooperative Innovation Center for Nuclear Fuel Cycle Technology and Equipment,University of South China(No.2019KFZ10)Hunan Provincial Innovation Foundation for Postgraduate(No.CX20230962).
文摘By combining experimental α-decay energies and half-lives, the α-particle preformation factor for nuclei around neutron magic numbers N of 126, 152, and 162 were extracted using the two-potential approach. The nuclei around the shell closure were more tightly bound than adjacent nuclei. Additionally, based on the WS4 mass model (Wang et al., Phys. Lett.B 734, 215 (2014)), we extended the two-potential approach to predict the α-decay half-lives of nuclei around N values of178 and 184 with Z of 119 and 120. We believe that our findings will serve as guidelines for future experimental studies.
基金supported by the National Key Research and Development Program(Nos.2023YFA1606901 and 2022YFA1602400)National Natural Science Foundation of China(Nos.U2230133,12275338,and 12388102)Open Fund of the CIAE Key Laboratory of Nuclear Data(No.JCKY2022201C152).
文摘We present new data on the^(63)Cu(γ,n)cross-section studied using a quasi-monochromatic and energy-tunableγbeam produced at the Shanghai Laser Electron Gamma Source to resolve the long-standing discrepancy between existing measurements and evaluations of this cross-section.Using an unfolding iteration method,^(63)Cu(γ,n)data were obtained with an uncertainty of less than 4%,and the inconsistencies between the available experimental data were discussed.Theγ-ray strength function of^(63)Cu(γ,n)was successfully extracted as an experimental constraint.We further calculated the cross-section of the radiative neutron capture reaction^(62)Cu(n,γ)using the TALYS code.Our calculation method enables the extraction of(n,γ)cross-sections for unstable nuclides.
基金supported by the National Natural Science Foundation of China(No.12005198).
文摘In this study,an end-to-end deep learning method is proposed to improve the accuracy of continuum estimation in low-resolution gamma-ray spectra.A novel process for generating the theoretical continuum of a simulated spectrum is established,and a convolutional neural network consisting of 51 layers and more than 105 parameters is constructed to directly predict the entire continuum from the extracted global spectrum features.For testing,an in-house NaI-type whole-body counter is used,and 106 training spectrum samples(20%of which are reserved for testing)are generated using Monte Carlo simulations.In addition,the existing fitting,step-type,and peak erosion methods are selected for comparison.The proposed method exhibits excellent performance,as evidenced by its activity error distribution and the smallest mean activity error of 1.5%among the evaluated methods.Additionally,a validation experiment is performed using a whole-body counter to analyze a human physical phantom containing four radionuclides.The largest activity error of the proposed method is−5.1%,which is considerably smaller than those of the comparative methods,confirming the test results.The multiscale feature extraction and nonlinear relation modeling in the proposed method establish a novel approach for accurate and convenient continuum estimation in a low-resolution gamma-ray spectrum.Thus,the proposed method is promising for accurate quantitative radioactivity analysis in practical applications.
基金funded by Taif University,Saudi Arabia,Project No.(TU-DSPP-2024-33)。
文摘Theβ-decay properties of^(67-80)As nuclei have been investigated within the framework of the proton-neutron quasi-particle random phase approximation(pn-QRPA)model.The nuclear deformation obtained from the finite range droplet model is used as an input parameter in the pn-QRPA model for the analysis ofβ-decay properties including Gamow-Teller strength distributions,log ft,β-decay half-lives and stellarβ^(±)decay rates.The predicted log ft values were fairly consistent with the observed data.The computedβ-decay half-lives matched the measured values by a factor of 10.The stellar rates were compared with the shell model outcomes.At high densities and temperatures,theβ^(+)and electron capture rates had a finite contribution.However,theβ^(-)and positron capture rates are only significant at high temperatures and low densities.The pn-QRPA rates outperformed the shell model rates by a factor of 22 or more.
基金supported by the National Natural Science Foundation of China(Nos.12375244 and 12135009)the Hunan Provincial Innovation Foundation for Postgraduate(Nos.CX20210007 and CX20230008)。
文摘In this study,we explore the impact of state-of-the-art laser fields on theαdecay half-life of deformed ground-state odd-A nuclei within the proton number range of 52–107.The calculations show that the presence of a laser field modulates theαdecay half-life by altering theαdecay penetration probability within a limited range.Moreover,the variance in the penetration probability rate of change between even–odd and odd–even nuclei is investigated.Furthermore,we investigate the rate of change of the penetration probability for the same parent nucleus with different neutron numbers,based on the characteristics of the odd-A nucleus.We found that the influence of the laser field on the penetration probability is determined by both the shell effect and odd–even staggering.This research contributes to the understanding of nuanced interactions between laser fields and nuclear decay processes.Therefore,valuable insights for future experiments in laser–nuclear physics are attainable using this study.
基金Funded by the Zibo Key Research and Development Project(No.2020XCCG0106)the Zibo Key Research and Development Project(No.2021SNPT0004)the Opening Project of Glass-based Functional Material Technology Innovation Center(No.GFMTIC2025C01)。
文摘We employed Monte Carlo simulations via Geant4 to model the interactions of^(60)Co gamma rays(1.25 MeV),electrons(0.1-10 MeV),and protons(0.5-10 MeV)with Ta_(2)O_(5)optical coatings.By analyzing secondary electron generation and energy deposition,we found that 1.0 MeV electrons and protons produce 67.5 and 67 secondary electrons per particle,respectively,compared to 116 from 1.25 MeV gamma rays in thick targets.Boltzmann-function fitting revealed depth-dependent ionization equivalence:0.582 gamma photons match the secondary electron yield of a 1.0 MeV electron,and 0.577 gamma photons match a 1.0 MeV proton.These results establish a framework to convert ground-based gamma-ray test data to space environment scenarios,accounting for critical differences in penetration depth-protons deposit energy within 10μm(coating layers),while gamma rays penetrate>100 mm into substrates.This provides a theoretical basis for evaluating radiation effects using existing^(60)Co facilities,enabling reliable predictions of optical component durability in complex space environments.
基金supported by the National Key R&D Program of China(Grant No.2023YFF0721700)the National Natural Science Foundation of China(Grant No.12475312).
文摘The development of low-cost and highly efficient thermal neutron detection materials to substitute the rare and expensive^(3)He gas is important for applications requiring thermal neutron detection.Lithium-based glass(Li glass)is a promising candidate due to its simple fabrication process and low cost.This paper reports the optical properties and scintillation performance of a new Ce^(3+)-doped Li glass,whose luminescence efficiency is significantly enhanced with a light yield of about 4770 ph/MeV,which is about 54%of that of BGO crystal,and the energy resolution is 14.5%for 662 keV gamma rays.The Ce^(3+)-doped Li glass shows a high light yield of about 7058 ph/neutron,which is about 1.18 times that of the reference GS20 glass.The Ce^(3+)-doped Li glass exhibits stronger gamma ray suppression capability compared to GS20 glass samples.Further optimizing the Ce^(3+)concentration and 6Li content is expected to achieve much superior neutron detection efficiency,positioning it as a promising alternative to^(3)He gas for efficient thermal neutron detection.
基金supported by the‘Young Scientist Scheme’of the National Key R&D Program of China(No.2021YFA1601500)National Natural Science Foundation of China(Nos.12075104,12375109,11875070,and 11935001)+1 种基金Anhui Project(Z010118169)Key Research Foundation of the Education Ministry of Anhui Province(No.2023AH050095)。
文摘Nuclearβ-decay,a typical decay process for unstable nuclei,is a key mechanism for producing heavy elements in the Universe.In this study,neural networks were employed to predictβ-decay half-lives and,for the first time,to identify abnormal trends in nuclearβ-decay half-lives based on deviations between experimental values and the predictions of neural networks.Nuclei exhibiting anomalous increases,abrupt peaks,sharp decreases,abnormal odd-even oscillations,and excessively large experimental errors in theirβ-decay half-lives,which deviate from systematic patterns,were identified through deviations.These anomalous phenomena may be associated with shell effects,shape coexistence,or discrepancies in the experimental data.The discovery and analysis of these abnormal nuclei provide a valuable reference for further investigations using sophisticated microscopic theories,potentially offering insights into new physics through studies of nuclearβ-decay half-lives.
基金supported by the National Natural Science Foundation of China(Nos.12105143 and 11975121)the China Postdoctoral Science Foundation(No.2023M741453)+1 种基金the Engineering Research Center of Nuclear Technology Application(No.HJSJYB2020-1)the Key Laboratory of Ionizing Radiation Metering and Safety Evaluation for Jiangsu Province Market Regulation,and the Jiangsu Province Excellent Postdoctoral Program(No.JB23057).
文摘Neutron-induced gamma-ray imaging is a spectroscopic technique that uses characteristic gamma rays to infer the elemental distribution of an object.Currently,this technique requires the use of large facilities to supply a high neutron flux and a time-consuming detection procedure involving direct collimating measurements.In this study,a new method based on low neutron flux was proposed.A single-pixel gamma-ray detector combined with random pattern gamma-ray masks was used to measure the characteristic gamma rays emitted from the sample.Images of the elemental distribution in the sample,comprising 30×30 pixels,were reconstructed using the maximum-likelihood expectation-maximization algorithm.The results demonstrate that the elemental imaging of the sample can be accurately determined using this method.The proposed approach,which eliminates the need for high neutron flux and scanning measurements,can be used for in-field imaging applications.
