As a fundamental property of nuclei,atomic masses are widely used in many domains of science and engineering.A reliable atomic mass table derived from the experimental data,where the atomic masses and the relevant exp...As a fundamental property of nuclei,atomic masses are widely used in many domains of science and engineering.A reliable atomic mass table derived from the experimental data,where the atomic masses and the relevant experi-mental information can be found conveniently,is in high demand by the research community.To meet the demands,the Atomic Mass Evaluation(AME)was initiated in 1950's and a series of AME mass tables have been published ever since.Currently the AME serves the research community by providing the most reliable and comprehensive information related to the atomic masses.The new atomic mass evaluation AME2016 was published in the March issue of Chinese Physics C as two com-plementary papers[1;2].展开更多
The NUBASE2020 evaluation contains the recommended values of the main nuclear physics properties for all nuclei in their ground and excited,isomeric(T1/2≥100 ns)states.It encompasses all experimental data published i...The NUBASE2020 evaluation contains the recommended values of the main nuclear physics properties for all nuclei in their ground and excited,isomeric(T1/2≥100 ns)states.It encompasses all experimental data published in primary(journal articles)and secondary(mainly laboratory reports and conference proceedings)references,together with the corresponding bibliographical information.In cases where no experimental data were available for a particular nuclide,trends in the behavior of specific properties in neighboring nuclei were examined and estimated values are proposed.Evaluation procedures and policies that were used during the development of this evaluated nuclear data library are presented,together with a detailed table of recommended values and their uncertainties.展开更多
A position-sensitive Schottky Cavity Doublet(SCD)was developed to enhance the accuracy of isochronousmass measurement at the Rare Radio-Isotope Ring(R3)at RIBF-RIKEN,Japan.The aim is to increase theaccuracy of positio...A position-sensitive Schottky Cavity Doublet(SCD)was developed to enhance the accuracy of isochronousmass measurement at the Rare Radio-Isotope Ring(R3)at RIBF-RIKEN,Japan.The aim is to increase theaccuracy of position measurement,which is used to correct the momentum spread,thus reducing the uncertainty inthe mass determination.The detector comprises a cylindrical reference cavity and elliptical position-sensitive cavity,which uses an offset beam-pipe to create a relation between the Schottky power and horizontal position.The uncertaintyin the power response can be improved by minimizing free parameters inside the power equation,providing asecond-order correction for the position determination.This requires a large dispersion and momentum spread to effectivelycharacterize the SCD acceptance,which simulations show is achieved when using^(76)Zn as a reference isotope.A key parameter to minimize is uncertainty of the impedance map,which relates power to position in the ellipticalcavity.We find that an uncertainty in impedance of 0.3Ωresults in a precision equal to that of the current massmeasurement method.Additionally,measuring momentum with the SCD enables the removal of other detectorsfrom the beam-line,which drastically reduces the yield of high-Z beams via charge-change interactions.展开更多
Non-destructive Schottky detectors are indispensable devices widely used in experiments at heavy-ion storage rings.In particular,they can be used to accurately determine the masses and lifetimes of short-lived exotic ...Non-destructive Schottky detectors are indispensable devices widely used in experiments at heavy-ion storage rings.In particular,they can be used to accurately determine the masses and lifetimes of short-lived exotic nuclear species.Single-ion sensitivity-which is the highest level of sensitivity-has been regularly achieved in the past by utilizing resonant cavity detectors.Recent designs and analysis methods aim to push the limits of measurement accuracy by increasing the dimensionality of the acquired data,namely,the position of the particle as well as the phase difference between several detectors.This paper describes current methods and future perspectives for Schottky detection techniques,with a focus on their application to mass and lifetime measurements of the most rare and simultaneously short-lived radio nuclides.展开更多
The rare radioactive-isotope(RI)ring is an isochronous storage ring for deriving the masses of extremely short-lived rare RIs.Since the successful commissioning experiment in 2015,the time of flight mass measurement t...The rare radioactive-isotope(RI)ring is an isochronous storage ring for deriving the masses of extremely short-lived rare RIs.Since the successful commissioning experiment in 2015,the time of flight mass measurement technique has been established through test experiments using unstable nuclei with well-known masses.The experiments for unknown masses were started in 2018.While conducting experiments,we continue to develop equipment to further improve the efficiency and precision of mass measurements.The upgraded kicker system can generate a magnetic field with an extractable duration equivalent to the revolution time of the ring.This is essential for extracting extremely rare events as well as shortening the measurement time compared with that in the initial experiments.New steering magnets make it possible to eliminate an uncertain vertical beam deviation that occurs upstream.As a result,we confirm that the extraction yield is increased.A new resonant Schottky pick-up is able to detect single particles in timeframes on the order of milliseconds.It will be useful not only for beam diagnostics but also for lifetime measurement experiments of extremely short-lived rare RIs planned as a future application.展开更多
This is the first of two articles(Part I and Part II)that presents the results of the new atomic mass evaluation,Ame2020.It includes complete information on the experimental input data that were used to derive the tab...This is the first of two articles(Part I and Part II)that presents the results of the new atomic mass evaluation,Ame2020.It includes complete information on the experimental input data that were used to derive the tables of recommended values which are given in Part II.This article describes the evaluation philosophy and procedures that were implemented in the selection of specific nuclear reaction,decay and mass-spectrometric data which were used in a least-squares fit adjustment in order to determine the recommended mass values and their uncertainties.All input data,including both the accepted and rejected ones,are tabulated and compared with the adjusted values obtained from the least-squares fit analysis.Differences with the previous Ame2016 evaluation are discussed and specific examples are presented for several nuclides that may be of interest to Ame users.展开更多
This is the second part of the new evaluation of atomic masses,Ame2020.Using least-squares adjustments to all evaluated and accepted experimental data,described in Part I,we derived tables with numerical values and gr...This is the second part of the new evaluation of atomic masses,Ame2020.Using least-squares adjustments to all evaluated and accepted experimental data,described in Part I,we derived tables with numerical values and graphs which supersede those given in Ame2016.The first table presents the recommended atomic mass values and their uncertainties.It is followed by a table of the influences of data on primary nuclides,a table of various reaction and decay energies,and finally,a series of graphs of separation and decay energies.The last section of this paper provides all input data references that were used in the Ame2020 and the Nubase2020 evaluations.展开更多
文摘As a fundamental property of nuclei,atomic masses are widely used in many domains of science and engineering.A reliable atomic mass table derived from the experimental data,where the atomic masses and the relevant experi-mental information can be found conveniently,is in high demand by the research community.To meet the demands,the Atomic Mass Evaluation(AME)was initiated in 1950's and a series of AME mass tables have been published ever since.Currently the AME serves the research community by providing the most reliable and comprehensive information related to the atomic masses.The new atomic mass evaluation AME2016 was published in the March issue of Chinese Physics C as two com-plementary papers[1;2].
基金This work was supported by the U.S.Department of Energy,Office of Science,Office of Nuclear Physics,under Contract No.DE-AC02-06CH11357(ANL)in part by the National Key Research and Development Program of China(Grant No.2016YFA0400504)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(CAS,Grant No.XDB34000000)(IMP)W.J.Huang acknowledges the financial support by the Max-Planck-Society.S.Naimi acknowledges the support of the RIKEN Pioneering Project Funding.
文摘The NUBASE2020 evaluation contains the recommended values of the main nuclear physics properties for all nuclei in their ground and excited,isomeric(T1/2≥100 ns)states.It encompasses all experimental data published in primary(journal articles)and secondary(mainly laboratory reports and conference proceedings)references,together with the corresponding bibliographical information.In cases where no experimental data were available for a particular nuclide,trends in the behavior of specific properties in neighboring nuclei were examined and estimated values are proposed.Evaluation procedures and policies that were used during the development of this evaluated nuclear data library are presented,together with a detailed table of recommended values and their uncertainties.
基金support from the State of Hesse within the Research Cluster ELEMENTS(project ID 500/10.006)。
文摘A position-sensitive Schottky Cavity Doublet(SCD)was developed to enhance the accuracy of isochronousmass measurement at the Rare Radio-Isotope Ring(R3)at RIBF-RIKEN,Japan.The aim is to increase theaccuracy of position measurement,which is used to correct the momentum spread,thus reducing the uncertainty inthe mass determination.The detector comprises a cylindrical reference cavity and elliptical position-sensitive cavity,which uses an offset beam-pipe to create a relation between the Schottky power and horizontal position.The uncertaintyin the power response can be improved by minimizing free parameters inside the power equation,providing asecond-order correction for the position determination.This requires a large dispersion and momentum spread to effectivelycharacterize the SCD acceptance,which simulations show is achieved when using^(76)Zn as a reference isotope.A key parameter to minimize is uncertainty of the impedance map,which relates power to position in the ellipticalcavity.We find that an uncertainty in impedance of 0.3Ωresults in a precision equal to that of the current massmeasurement method.Additionally,measuring momentum with the SCD enables the removal of other detectorsfrom the beam-line,which drastically reduces the yield of high-Z beams via charge-change interactions.
基金support by the State of Hesse within the Research Cluster ELEMENTS (Project ID 500/10.006)support by the project "NRW-FAIR"+1 种基金a part of the programme "Netzwerke 2021"an initiative of the Ministry of Culture and Science of the State of North Rhine-Westphalia。
文摘Non-destructive Schottky detectors are indispensable devices widely used in experiments at heavy-ion storage rings.In particular,they can be used to accurately determine the masses and lifetimes of short-lived exotic nuclear species.Single-ion sensitivity-which is the highest level of sensitivity-has been regularly achieved in the past by utilizing resonant cavity detectors.Recent designs and analysis methods aim to push the limits of measurement accuracy by increasing the dimensionality of the acquired data,namely,the position of the particle as well as the phase difference between several detectors.This paper describes current methods and future perspectives for Schottky detection techniques,with a focus on their application to mass and lifetime measurements of the most rare and simultaneously short-lived radio nuclides.
基金Supported by RIKEN Pioneering Project funding and JSPS KAKENHI(17H01123,18H03695,21H04461,23K25876.)。
文摘The rare radioactive-isotope(RI)ring is an isochronous storage ring for deriving the masses of extremely short-lived rare RIs.Since the successful commissioning experiment in 2015,the time of flight mass measurement technique has been established through test experiments using unstable nuclei with well-known masses.The experiments for unknown masses were started in 2018.While conducting experiments,we continue to develop equipment to further improve the efficiency and precision of mass measurements.The upgraded kicker system can generate a magnetic field with an extractable duration equivalent to the revolution time of the ring.This is essential for extracting extremely rare events as well as shortening the measurement time compared with that in the initial experiments.New steering magnets make it possible to eliminate an uncertain vertical beam deviation that occurs upstream.As a result,we confirm that the extraction yield is increased.A new resonant Schottky pick-up is able to detect single particles in timeframes on the order of milliseconds.It will be useful not only for beam diagnostics but also for lifetime measurement experiments of extremely short-lived rare RIs planned as a future application.
文摘This is the first of two articles(Part I and Part II)that presents the results of the new atomic mass evaluation,Ame2020.It includes complete information on the experimental input data that were used to derive the tables of recommended values which are given in Part II.This article describes the evaluation philosophy and procedures that were implemented in the selection of specific nuclear reaction,decay and mass-spectrometric data which were used in a least-squares fit adjustment in order to determine the recommended mass values and their uncertainties.All input data,including both the accepted and rejected ones,are tabulated and compared with the adjusted values obtained from the least-squares fit analysis.Differences with the previous Ame2016 evaluation are discussed and specific examples are presented for several nuclides that may be of interest to Ame users.
基金This work is supported in part by the Strategic Priority Research Program of Chinese Academy of Sciences(CAS,Grant No.XDB34000000)the National Key Research and Development Program of China(Grant No.2016YFA0400504)the U.S.Department of Energy,Of-fice of Science,Office of Nuclear Physics,under Contract No.DE-AC02-06CH11357.
文摘This is the second part of the new evaluation of atomic masses,Ame2020.Using least-squares adjustments to all evaluated and accepted experimental data,described in Part I,we derived tables with numerical values and graphs which supersede those given in Ame2016.The first table presents the recommended atomic mass values and their uncertainties.It is followed by a table of the influences of data on primary nuclides,a table of various reaction and decay energies,and finally,a series of graphs of separation and decay energies.The last section of this paper provides all input data references that were used in the Ame2020 and the Nubase2020 evaluations.
