Near degeneracy between two quantum states is usually associated with fundamental symmetries and symmetry breakings in complex many-body systems like atomic nuclei.Pseudospin symmetry was introduced to describe energy...Near degeneracy between two quantum states is usually associated with fundamental symmetries and symmetry breakings in complex many-body systems like atomic nuclei.Pseudospin symmetry was introduced to describe energy degeneracy between single-particle states with quantum numbers(n,l,j=l+1/2)and(n-1,l+2,j=l+3/2)[1-3].展开更多
Backbending played a pivotal role in the progress of high-spin structure research[1].This phennomenon was interpreted as a result of band-crossing between two intrinsic configurations which dominate lower-and higher-s...Backbending played a pivotal role in the progress of high-spin structure research[1].This phennomenon was interpreted as a result of band-crossing between two intrinsic configurations which dominate lower-and higher-spin region.Usually the two configurations are differed by two nucleons,which are paired in the former,and unpaired in the latter.According to the strong-coupling scheme,two unpaired quasi-particles can couple to both high-K and low-K configurations in deformed nuclei.Usually only the lower can be identified experimentally since it is favoured by the Gallagher-Moszkowski spin-spin coupling rules[2].展开更多
Isomeric I^(π)=8^(-) states have been observed in the even-even N=74 nuclei ^(138)Gd[1],^(136)Sm[2],^(134)Nd[3],^(132)Ce[4],^(130)Ba[5],^(128)Xe[6]with half-lives ranging from nanoseconds(Xe)to milliseconds(Ba,Ce).Ro...Isomeric I^(π)=8^(-) states have been observed in the even-even N=74 nuclei ^(138)Gd[1],^(136)Sm[2],^(134)Nd[3],^(132)Ce[4],^(130)Ba[5],^(128)Xe[6]with half-lives ranging from nanoseconds(Xe)to milliseconds(Ba,Ce).Rotational bands built on the K^(π)=8^(-) isomer were identified in all these isotones,with the exception of 130Ba.The singleparticle configuration of the isomers have been deduced from theΔI=2 toΔI=1γ-ray intensity branching ratios,which allowed to extract the(gKgR)/Q0 values,and therefore the quasi-particle configuration of the state.展开更多
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
This paper presents the NUBASE2016 evaluation that contains the recommended values for nuclear and decay properties of 3437 nuclides in their ground and excited isomeric （T1/2〉 100 ns） states. All nuclides for whic...This paper presents the NUBASE2016 evaluation that contains the recommended values for nuclear and decay properties of 3437 nuclides in their ground and excited isomeric （T1/2〉 100 ns） states. All nuclides for which any experimental information is known were considered. NUSASE2016 covers all data published by October 2016 in primary （journal articles） and secondary （mainly laboratory reports and conference proceedings） references, together with the corresponding bibliographical information. During the development of NUBASE2016, the data available in the ＂Evaluated Nuclear Structure Data File＂ （ENSDF） database were consulted and critically assessed for their validity and completeness. Furthermore, a large amount of new data and some older experimental results that were missing from ENSDF were compiled, evaluated and included in NUBASE2016. The atomic mass values were taken from the ＂Atomic Mass Evaluation＂ （AME2016, second and third parts of the present issue）. In cases where no experimental data were available for a particular nuclide, trends in the behavior of specific properties in neighboring nuclides （TNN） were examined. This approach allowed to estimate values for a range of properties that are labeled in NUBASE2016 as ＂non-experimental＂ （flagged ＂#＂）. Evaluation procedures and policies used during the development of this database are presented, together with a detailed table of recommended values and their uncertainties.展开更多
This paper is the second part of the new evaluation of atomic masses, AME2016. Using least-squares adjustments to all evaluated and accepted experimental data, described in Part I, we derive tables with numerical valu...This paper is the second part of the new evaluation of atomic masses, AME2016. Using least-squares adjustments to all evaluated and accepted experimental data, described in Part I, we derive tables with numerical values and graphs to replace those given in AME2012. The first table lists 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 lists all references of the input data used in the AME2016 and the NUBASE2016 evaluations （first paper in this issue）.展开更多
This paper is the first of two articles （Part I and Part II） that presents the results of the new atomic mass evaluation, AME2016. It includes complete information on the experimental input data （also including unu...This paper is the first of two articles （Part I and Part II） that presents the results of the new atomic mass evaluation, AME2016. It includes complete information on the experimental input data （also including unused and rejected ones）, as well as details on the evaluation procedures used to derive the tables of recommended values given in the second part. This article describes the evaluation philosophy and procedures that were implemented in the selection of specific nuclear reaction, decay and mass-spectrometric results. These input values were entered in the least-squares adjustment for determining the best values for the atomic masses and their uncertainties. Details of the calculation and particularities of the AME are then described. All accepted and rejected data, including outweighted ones, are presented in a tabular format and compared with the adjusted values obtained using the least-squares fit analysis. Differences with the previous AME2012 evaluation are discussed and specific information is presented for several cases that may be of interest to AME users. The second AME2016 article gives a table with the recommended values of atomic masses, as well as tables and graphs of derived quantities, along with the list of references used in both the AME2016 and the NUBASE2016 evaluations （the first paper in this issue）.展开更多
This paper presents the NUBASE2012 evaluation that contains the recommended values for nuclear and decay properties of nuclides in their ground and excited isomeric （T1/2≥ 100 ns） states. All nuclides for which som...This paper presents the NUBASE2012 evaluation that contains the recommended values for nuclear and decay properties of nuclides in their ground and excited isomeric （T1/2≥ 100 ns） states. All nuclides for which some experimental information is known are considered. NUBASE2012 covers all up to date experimental data published in primary （journal articles） and secondary （mainly laboratory reports and conference proceedings） references, together with the corresponding bibliographical information. During the development of NUBASE2012, the data available in the ＂Evaluated Nuclear Structure Data File＂ （ENSDF） database were consulted, and critically assessed of their validity and completeness. Furthermore, a large amount of new and somewhat older experimental results that were missing in ENSDF were compiled, evaluated and included in NUI3ASE2012. The atomic mass values were taken from the ＂Atomic Mass Evaluation＂ （AME2012, second and third parts of the present issue）. In cases where no experimental data were available for a particular nuclide, trends in the behavior of specific properties in neighboring nuclei （TNN） were examined. This approach allowed to estimate, whenever possible, values for a range of properties, and are labeled in NUBASE2012 as ＂non-experimental＂ （flagged ＂#＂）. Evaluation procedures and policies that were used during the development of this database are presented, together with a detailed table of recommended values and their uncertainties.展开更多
This paper is the second part of the new evaluation of atomic masses, AME2012. From the results of a leastsquares calculation, described in Part I, for all accepted experimental data, we derive here tables and graphs ...This paper is the second part of the new evaluation of atomic masses, AME2012. From the results of a leastsquares calculation, described in Part I, for all accepted experimental data, we derive here tables and graphs to replace those of AME2003. The first table lists atomic masses. It is followed by a table of the influences of data on primary nuclides, a table of separation energies and reaction energies, and finally, a series of graphs of separation and decay energies. The last section in this paper lists all references to the input data used in Part I of this AME2012 and also to the data included in the NUBASE2012 evaluation （first paper in this issue）.展开更多
This paper is the first of two articles （Part I and Part II） that presents the results of the new atomic mass evaluation, AME2012. It includes complete information on the experimental input data （including not used...This paper is the first of two articles （Part I and Part II） that presents the results of the new atomic mass evaluation, AME2012. It includes complete information on the experimental input data （including not used and rejected ones）, as well as details on the evaluation procedures used to derive the tables with recommended values given in the second part. This article describes the evaluation philosophy and procedures that were implemented in the selection of specific nuclear reaction, decay and mass-spectrometer results. These input values were entered in the least-squares adjustment procedure for determining the best values for the atomic masses and their uncertainties. Calculation procedures and particularities of the AME are then described. All accepted and rejected data, including outweighed ones, are presented in a tabular format and compared with the adjusted values （obtained using the adjustment procedure）. Differences with the previous AME2003 evaluation are also discussed and specific information is presented for several cases that may be of interest to various AME users. The second AME2012 article, the last one in this issue, gives a table with recommended values of atomic masses, as well as tables and graphs of derived quantifies, along with the list of references used in both this AME2012 evaluation and the NUBASE2012 one （the first paper in this issue）.展开更多
文摘Near degeneracy between two quantum states is usually associated with fundamental symmetries and symmetry breakings in complex many-body systems like atomic nuclei.Pseudospin symmetry was introduced to describe energy degeneracy between single-particle states with quantum numbers(n,l,j=l+1/2)and(n-1,l+2,j=l+3/2)[1-3].
文摘Backbending played a pivotal role in the progress of high-spin structure research[1].This phennomenon was interpreted as a result of band-crossing between two intrinsic configurations which dominate lower-and higher-spin region.Usually the two configurations are differed by two nucleons,which are paired in the former,and unpaired in the latter.According to the strong-coupling scheme,two unpaired quasi-particles can couple to both high-K and low-K configurations in deformed nuclei.Usually only the lower can be identified experimentally since it is favoured by the Gallagher-Moszkowski spin-spin coupling rules[2].
文摘Isomeric I^(π)=8^(-) states have been observed in the even-even N=74 nuclei ^(138)Gd[1],^(136)Sm[2],^(134)Nd[3],^(132)Ce[4],^(130)Ba[5],^(128)Xe[6]with half-lives ranging from nanoseconds(Xe)to milliseconds(Ba,Ce).Rotational bands built on the K^(π)=8^(-) isomer were identified in all these isotones,with the exception of 130Ba.The singleparticle configuration of the isomers have been deduced from theΔI=2 toΔI=1γ-ray intensity branching ratios,which allowed to extract the(gKgR)/Q0 values,and therefore the quasi-particle configuration of the state.
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 has been undertaken with the efidorsement of the IUPAP Commission on Symbols, Units, Nomenclature, Atomic Masses and Fundamental Constants （SUNAMCO）.
文摘This paper presents the NUBASE2016 evaluation that contains the recommended values for nuclear and decay properties of 3437 nuclides in their ground and excited isomeric （T1/2〉 100 ns） states. All nuclides for which any experimental information is known were considered. NUSASE2016 covers all data published by October 2016 in primary （journal articles） and secondary （mainly laboratory reports and conference proceedings） references, together with the corresponding bibliographical information. During the development of NUBASE2016, the data available in the ＂Evaluated Nuclear Structure Data File＂ （ENSDF） database were consulted and critically assessed for their validity and completeness. Furthermore, a large amount of new data and some older experimental results that were missing from ENSDF were compiled, evaluated and included in NUBASE2016. The atomic mass values were taken from the ＂Atomic Mass Evaluation＂ （AME2016, second and third parts of the present issue）. In cases where no experimental data were available for a particular nuclide, trends in the behavior of specific properties in neighboring nuclides （TNN） were examined. This approach allowed to estimate values for a range of properties that are labeled in NUBASE2016 as ＂non-experimental＂ （flagged ＂#＂）. Evaluation procedures and policies used during the development of this database are presented, together with a detailed table of recommended values and their uncertainties.
基金supported in part by the National Key Program for S&T Research and Development (Contract No. 2016YFA0400504)the Major State Basic Research Development Program of China (Contract No. 2013CB834401)+3 种基金supported by the U.S. Department of Energy, Office of Science,Office of Nuclear Physics,under Contract No.DE-AC0206CH11357the support from the China Scholarship Council,grant No. 201404910496the support of “RIKEN Pioneering Project Funding” from the Riken projectthe support of “Light of West China Program” of Chinese Academy of Sciences
文摘This paper is the second part of the new evaluation of atomic masses, AME2016. Using least-squares adjustments to all evaluated and accepted experimental data, described in Part I, we derive tables with numerical values and graphs to replace those given in AME2012. The first table lists 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 lists all references of the input data used in the AME2016 and the NUBASE2016 evaluations （first paper in this issue）.
基金This work has been undertaken with the endorsement of the IUPAP Commission on Symbols, Units, Nomenclature, Atomic Masses and Fundamental Constants （SUNAMCO）.
文摘This paper is the first of two articles （Part I and Part II） that presents the results of the new atomic mass evaluation, AME2016. It includes complete information on the experimental input data （also including unused and rejected ones）, as well as details on the evaluation procedures used to derive the tables of recommended values given in the second part. This article describes the evaluation philosophy and procedures that were implemented in the selection of specific nuclear reaction, decay and mass-spectrometric results. These input values were entered in the least-squares adjustment for determining the best values for the atomic masses and their uncertainties. Details of the calculation and particularities of the AME are then described. All accepted and rejected data, including outweighted ones, are presented in a tabular format and compared with the adjusted values obtained using the least-squares fit analysis. Differences with the previous AME2012 evaluation are discussed and specific information is presented for several cases that may be of interest to AME users. The second AME2016 article gives a table with the recommended values of atomic masses, as well as tables and graphs of derived quantities, along with the list of references used in both the AME2016 and the NUBASE2016 evaluations （the first paper in this issue）.
文摘This paper presents the NUBASE2012 evaluation that contains the recommended values for nuclear and decay properties of nuclides in their ground and excited isomeric （T1/2≥ 100 ns） states. All nuclides for which some experimental information is known are considered. NUBASE2012 covers all up to date experimental data published in primary （journal articles） and secondary （mainly laboratory reports and conference proceedings） references, together with the corresponding bibliographical information. During the development of NUBASE2012, the data available in the ＂Evaluated Nuclear Structure Data File＂ （ENSDF） database were consulted, and critically assessed of their validity and completeness. Furthermore, a large amount of new and somewhat older experimental results that were missing in ENSDF were compiled, evaluated and included in NUI3ASE2012. The atomic mass values were taken from the ＂Atomic Mass Evaluation＂ （AME2012, second and third parts of the present issue）. In cases where no experimental data were available for a particular nuclide, trends in the behavior of specific properties in neighboring nuclei （TNN） were examined. This approach allowed to estimate, whenever possible, values for a range of properties, and are labeled in NUBASE2012 as ＂non-experimental＂ （flagged ＂#＂）. Evaluation procedures and policies that were used during the development of this database are presented, together with a detailed table of recommended values and their uncertainties.
文摘This paper is the second part of the new evaluation of atomic masses, AME2012. From the results of a leastsquares calculation, described in Part I, for all accepted experimental data, we derive here tables and graphs to replace those of AME2003. The first table lists atomic masses. It is followed by a table of the influences of data on primary nuclides, a table of separation energies and reaction energies, and finally, a series of graphs of separation and decay energies. The last section in this paper lists all references to the input data used in Part I of this AME2012 and also to the data included in the NUBASE2012 evaluation （first paper in this issue）.
文摘This paper is the first of two articles （Part I and Part II） that presents the results of the new atomic mass evaluation, AME2012. It includes complete information on the experimental input data （including not used and rejected ones）, as well as details on the evaluation procedures used to derive the tables with recommended values given in the second part. This article describes the evaluation philosophy and procedures that were implemented in the selection of specific nuclear reaction, decay and mass-spectrometer results. These input values were entered in the least-squares adjustment procedure for determining the best values for the atomic masses and their uncertainties. Calculation procedures and particularities of the AME are then described. All accepted and rejected data, including outweighed ones, are presented in a tabular format and compared with the adjusted values （obtained using the adjustment procedure）. Differences with the previous AME2003 evaluation are also discussed and specific information is presented for several cases that may be of interest to various AME users. The second AME2012 article, the last one in this issue, gives a table with recommended values of atomic masses, as well as tables and graphs of derived quantifies, along with the list of references used in both this AME2012 evaluation and the NUBASE2012 one （the first paper in this issue）.
