2021 Impact Factor 2.944 Impact factor of Chinese Physics C is 3.6 in 2023 Impact factor of Chinese Physics C is 3.6 in 2022 2021 Impact Factor 2.944 Impact factor of Chinese Physics C is 3.6 in 2023
Advanced Search
Chinese Physics C> 2021, Vol. 45> Issue(3) : 030001 DOI: 10.1088/1674-1137/abddae

The NUBASE2020 evaluation of nuclear physics properties

  • 1.

     Physics Division, Argonne National Laboratory, Lemont, IL 60439, USA

  • 2.

     Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China

  • 3.

     School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China

  • 4.

     Advanced Energy Science and Technology Guangdong Laboratory, Huizhou 516003, China

  • 5.

     Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany

  • 6.

     Université Paris-Saclay, CNRS/IN2P3, IJCLab, 91405 Orsay, France

  • 7.

     RIKEN Nishina Center, Wako, Saitama 351-0198, Japan

  • 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.

  • 1. Introduction

    NUBASE2020 is an evaluated nuclear data library that contains the recommended values of the main nuclear physics properties: masses, excitation energies (for excited isomers), half-lives, spins and parities and decay modes, and their intensities, for all known nuclei in their ground and excited, isomeric (T 1/2 ≥ 100 ns) states. It also includes information for yet unobserved nuclides that is based on systematic trends of nuclear properties in neighboring nuclei. The present publication includes updated results for these properties, which were reported in previous versions of this library [1–4]. The recommended data are presented in Table I.

    The information included in NUBASE2020 represents the fundamental building blocks of the modern nuclear physics, and specifically of the nuclear structure and nuclear astrophysics research. One of the main applications of NUBASE2020 is the “Atomic Mass Evaluation” (AME2020 - the second and third articles included in this issue) where it is imperative to have an unambiguous identification of all states involved in a particular decay, reaction or mass-spectrometry measurement. This is the main reason for coupling the two evaluations together in the present issue. Furthermore, with the advances of modern mass-spectrometry techniques and the availability of intense stable and rare-isotope beams, a large number of short-lived nuclei can be produced in a single experiment and their masses can be measured with a high precision. Thus, NUBASE2020 can be a trusted source of information in future mass measurements, where an unambiguous identification of specific nuclides in complex mass-spectrometry data would be required.

    NUBASE2020 also serves nuclear structure research, astrophysics network calculations, and theoretical studies of nuclear properties, where complete, up-to-date and reliable data for all known nuclei are needed. It can be particularly useful in present and future studies of nuclei and their properties at the major nuclear physics facilities around the world, such as FAIR, ISOLDE and SPIRAL2 (Europe), ATLAS and FRIB (USA), HIAF (China), RIBF at RIKEN (Japan), ISAC and ARIEL (Canada), and elsewhere.

    Furthermore, the evaluated data included in NUBASE2020 are a valuable source of information for specialists in a number of applied nuclear fields, such as safeguards, nuclear forensics, reactor engineering, waste management, material analysis, medical diagnostics and radiotherapy, and elsewhere, where one needs to access reliable nuclear physics information for any nuclide.

    The recommended data included in NUBASE2020 fulfill several user-demanded requirements, namely that they are: a) complete − include all measured quantities and their uncertainties, b) up-to-date − include results from all recent publications, c) credible and reliable − identify and resolve contradictory results that exist in the scientific literature, as well as in other nuclear physics databases, d) properly referenced − provide comprehensive bibliographical information for all included properties.

    In general, NUBASE2020 was updated via three different routes: a) directly from the literature by compiling and evaluating data that were published in primary (nuclear physics journals) and secondary (abstracts, conference proceedings, private communications, theses, arXiv publications and laboratory reports) references; b) by consulting, and when merited by adopting, recommendations made in topical evaluations that include nuclear properties covered by NUBASE (see the text for details); c) by consulting, and when merited by adopting, recommended values from the “Evaluated Nuclear Structure Data File” (ENSDF) database [5].

    It is important to note that data presented in ENSDF and in other topical evaluations were carefully examined, and only results that were found to be valid and up-to-date were considered. In general, the content of ENSDF is very large, since it encompasses the complex nuclear structure and decay properties for all nuclei and all excited nuclear states. Maintenance of this library requires an enormous effort and it is not surprising that occasionally some older data are missing or misrepresented, and that some recent data are not included. When such cases were identified, the data were re-evaluated and the corresponding conclusions were added as comments in Table I.

    The content of NUBASE2020, together with the adopted policies that were used during the development of this nuclear physics data library, is described below. All experimental data available to the authors by October 30, 2020 were considered.

    2. Content of NUBASE2020

    The NUBASE2020 evaluation contains recommended properties for the ground state of 3340 nuclides and for 1938 excited isomeric (T 1/2 ≥ 100 ns) states, derived from all available experimental data. It also includes information for yet unobserved nuclei (218 in their ground state and 45 excited isomers) whose properties were estimated by following the systematic trends in neighboring nuclei (TNN, see section 3.1).

    For each nuclide and for each state (ground or isomeric), the following properties were compiled and, when necessary, evaluated: mass excess, excitation energy of the excited isomeric state, half-life, spin and parity, decay modes and their intensities, isotopic abundance (for stable nuclides), year of discovery and the corresponding bibliographical information for all experimental values of the above items.

    2.1 Mass excess

    In general, the knowledge of atomic masses can provide valuable information on the lifetimes of nuclear states and their decay modes, and in particular on the β -delayed particle decay probabilities for nuclei far from the line of stability.

    The mass-excess values and their uncertainties that are presented in Table I were adopted from the latest edition of the Atomic Mass Evaluation, AME2020, as described in the second and third articles of the present issue. Figure 1 displays the uncertainties of the mass-excess values as a function of N and Z.

    Figure 1

    Figure 1.  Nuclear chart displaying the mass-excess uncertainties for all nuclei in their ground state.
    DownLoad: Full-Size Img PowerPoint

    2.2 Isomers

    Nuclear isomers are excited, intrinsic (single-particle in nature) states with lifetimes ranging from nanoseconds (or even shorter) to years. There are several recent compilations and review articles, where the physics of nuclear isomers was discussed in detail and the reader is referred to Refs. [6, 7] and references therein.

    Following the NUBASE2003 publication [2], the present evaluation includes isomeric states with half-lives longer than 100 ns. Although this limit is somewhat arbitrary, the main reason for this choice was to include all short-lived isomers that can be directly produced at the present and future accelerator beam facilities and that can survive the time-of-flight path of the employed recoil mass separator, and as a consequence, their decay properties and/or masses can be directly measured.

    Figure 2 shows a compilation of all such known isomers as a function of N and Z.

    Figure 2

    Figure 2.  Nuclear chart displaying isomeric states with T 1/2 ≥ 100 ns. For a given isotope where multiple isomers exist, only the longest-lived state is plotted.
    DownLoad: Full-Size Img PowerPoint

    Isomers are listed in Table I in the order of increasing excitation energy and they are identified by the letters ‘m’, ‘n’, ‘p’, ‘q’, or ‘r’ which are appended to the nuclide name, e.g. 90 Nb for the ground state, 90 Nb m for the first excited isomer, 90 Nb n , 90 Nb p , 90 Nb q , and 90 Nb r for the second, third, fourth and fifth ones, respectively. In four cases, namely 98 Y, 174 Lu, 179 Ta and 214 Ra, a sixth isomer is presented and they were labeled with the letter ‘x’ (see the Explanation of Table I for details).

    The excitation energy of an isomeric states is determined by different experimental methods, which are generally attributed to the category of either internal or external relations. A typical internal relation involves the γ -ray energy, or the energies of a cascade of γ rays, associated with the isomer decay. The most-accurate values for the excitation energies of isomers that are deduced by this approach can be determined by a least-squares fit to the energies of all γ rays observed along the decay path of a particular isomer. In cases where internal relations cannot be established, connections to other nuclides (external relations) can be used to deduce the mass difference (excitation energy) between the ground state and isomers, and the excitation energies are taken from AME2020.

    The method used to establish the external relation for a particular isomer (the origin) is indicated by a two-letter code in Table I, next to the isomer excitation energy (see the Explanation of Table I for details). For internal relations, the origin field is left blank and the numerical values are taken either from ENSDF or from literature updates, where a least-squares fit to the measured γ -ray energies was performed, whenever possible.

    There are also cases where the energy difference between the isomer and the ground state can be obtained by both the internal and one, or more, external relations with comparable accuracies. In such cases, the excitation energy of the isomer is taken from AME2020. For example, the mass of 178 Lu m is determined in AME2020 at 66% from E x (IT) = 120(3) keV [1993Bu02] and at 34% from 176 Lu(t,p) 178 Lu m = 4482(5) keV [1981Gi01], resulting in an adjusted excitation energy of 123.8(2.6) keV for the isomer.

    In contrast to ENSDF, where the isomer excitation energies may not be quantified and are often given as floating levels with ‘+X’, ‘+Y’, etc., estimated values are always provided in NUBASE2020, based on theoretical considerations or TNN. In such cases, the reported excitation energies are considered as a non-experimental quantity and the values are flagged with the symbol ‘#’.

    When the existence of an isomer is uncertain and it is still under discussion, it is flagged with ‘EU’ (“Existence Uncertain”) in the origin field. A comment is usually added to indicate why the existence of this state is questioned or where this issue is discussed in more detail. Eleven isomers, namely 138 Pm m , 142 Nd m , 144 Cs n , 152 Pm n , 156 Tm m , 162 Lu n , 174 W m , 174 W n , 185 Bi n , 190 Tl n , and 273 Ds m are treated in this way in the present evaluation. Nevertheless, the mass excess and excitation energy values are given for all of them, except for 138 Pm m , 142 Nd m , 144 Cs n , 152 Pm n , 174 W m , 174 W n , and 190 Tl n , where the existence is strongly doubted.

    When an isomer was initially reported as “discovered”, but later this was proven to be an error, such a case is flagged with ‘RN’ (“Reported Non-existent”) in the origin field. Nine isomers, namely 76 Cu m , 84 Ga m , 84 As m , 85 Nb n , 86 Nb n , 117 La m , 181 Pb m , 196 Pb m , and 197 Bi n are treated in this way and no mass excess or excitation energy values are given. Similarly to the ‘EU’ cases, a “non-exist” label is also added. The use of the two flags, ‘EU’ and ‘RN’, was extended to cases where the discovery of a nuclide is questioned (e.g. 260 Fm or 289 Lv or 293 Og). However, an estimate for the ground state mass, derived from Trends from the Mass Surface (TMS), is always given in AME2020 and NUBASE2020.

    Sometimes, upper and lower limits are known for the excitation energy of the isomeric state. Such cases are treated with uniform probability distribution, as explained in section 3.2. For example, there is solid experimental evidence [1974De47] that the excitation energy of the 162 Tm m isomer is between the 66.9 keV and 192.0 keV levels and this information is presented (after rounding) in Table I as Ex=130(40) keV.

    When it is not clear which state is the ground state and which one is the isomer, the flag ‘ ∗ ’ is added in Table I. Similarly, when the uncertainty of the isomer excitation energy, Δ Ex , is relatively large compared to Ex , e.g. Δ Ex > Ex/2 , the assignment of the level as a ground or isomeric state is also considered to be uncertain and it is flagged with the symbol ‘ ∗ ’, as well.

    Based on new experimental mass information, the ordering of several ground and excited isomeric states was reversed in the present work, when compared to the recommendations in ENSDF, and such cases are flagged with the symbol ‘&’ in Table I. In a few other instances, evidence was found for a state that is located below the adopted in ENSDF ground state and such results were also flagged with the symbol ‘&’ in Table I. It is worth noting that because of the coupling between NUBASE2020 and AME2020 all changes in the ordering of nuclear levels are firmly established and synchronized.

    2.2.1   Isobaric analog states

    NUBASE2020 contains information for 205 Isobaric Analog States (IAS), which are labeled in Table I with the isospin multiplet value, T. Their excitation energies were determined via either the “internal” or “external” relation. The IAS nuclides are generally marked with the i or j superscripts, except for eight excited isomers, 16 N m , 26 Al m , 34 Cl m , 38 K m , 46 V m , 50 Mn m , 54 Co m , and 70 Br m . The isospin value is not given for most nuclei in their ground state, since they have T = ∣Tz∣ = 12 ∣(N−Z)∣ . However, it is included for the ground state of the N=Z , odd-odd 34 Cl, 42 Sc, 46 V, 50 Mn, 54 Co, 62 Ga, 66 As, 70 Br, and 74 Rb ( T=1 ) and 30 P, 38 K, and 58 Cu ( T=0 ) nuclides.

    Detailed experimental information about IAS was recently compiled in Refs. [8, 9].

    2.3 Half-life

    The lifetime is a fundamental property of a nuclear level. It is related to the total decay width, Γ , a linear sum of all partial decay widths ( γ ray, conversion electrons, α decay, β decay, fission, etc.), through the uncertainty relationship:

    Γ=ℏτ

    		(1)

    where τ = T 1/2 /ln(2) is the level mean life and T 1/2 is the half-life.

    Figures 3 displays the ground-state half-life as a function of N and Z for all nuclei included in Table I.

    Figure 3

    Figure 3.  Nuclear chart displaying the ground-state half-lives for all nuclei.
    DownLoad: Full-Size Img PowerPoint

    Some light nuclei (A < 30) that are located beyond the particle drip-lines are known to exist for a very short time before disintegrating by particle emissions. In such cases only the total level width can be measured and the half-life is deduced by means of equation 1 (in convenient units):

    T1/2[s]≃4.562×10−22/Γ[MeV]

    		(2)

    where Γ is the total width in the center of mass frame. The heaviest nuclide whose half-life is determined by this approach is 29 Cl.

    The following units are used in NUBASE2020 for a convenient display of half-lives: seconds (s) and its sub-units, minutes (m), hours (h), days (d) and years (y), and its sub-units (see Explanation of Table I for details). While several definitions can be used to convert values between years and days or seconds, such as Julian year, Gregorian year, Sidereal year, Tropical year and others, the conversion via Tropical year is adopted in NUBASE2020:

    1y=365.2422d=31556926s

    When more than one value is known for the half-life of a particular level, a statistical analysis was performed in accordance with the policies outlined in section 3.2. Experimental half-lives are sometimes given in the literature with most probable lower and upper limits. Such cases are treated with uniform probability distribution, as explained in section 3.2. For example, the half-life of 97 In m is given as 1.2 μ s ≤ T 1/2 ≤ 230 μ s in Ref. [2018Pa20] and the recommended value in NUBASE2020 is T 1/2 = 120(70) μ s. Half-lives with asymmetric uncertainties are also frequently reported in the literature. Since it is envisioned that NUBASE2020 will be used by specialists in various application fields, such values are symmetrized prior to performing any statistical analyses, as described in section 3.3.

    In experiments where rare events were detected, for example in studies of super-heavy nuclei, the half-lives reported in different publications were not directly averaged. Instead, when the information presented in the literature was sufficient, the time information associated with the individual events was combined and analyzed, as prescribed by Schmidt et. al. [1984Sc13]. In recent review articles that deal with properties of super-heavy nuclei [2014Kh04,2016Fo10,2016Ho09,2017Og01] events from several experiments were combined together in order to determine the best values. We have adopted these half-life values, rather than averaging the individual results.

    In cases of long-lived nuclides that are of importance to metrology and other applications, all available experimental data were carefully examined, including values published by various metrology laboratories over many years. As a policy, we adopted the latest reported value by a particular laboratory, including the latest results published by Unterweger and Fitzgerald [10], which superseded the earlier assessment made by the same authors [11].

    An upper or a lower limit for the half-life value is given in Table I for nuclides identified using a time-of-flight technique. The following policies were implemented: a) for observed nuclides, the lower limit for the half-life is given in the place of the uncertainty field. However, such a value should be used with caution, since it may be far shorter than the actual level half-life. In order to avoid confusion, a somewhat more realistic estimate, derived from TNN and flagged with #, is also given (see for example the data entry for 44 Si). The same notation is also used for half-life limits of very long-lived (stable) nuclei (see for example the data entry for 188 Os); b) for nuclides that were looked for, but not observed, the upper limit is given in the place of the uncertainty field. For example, upper limits were estimated for a number of unobserved nuclides by F. Pougheon [1993Po.A], based on the time-of-flight information and the production yields expected from TNN (see for example the data entry for 21 Al).

    In the course of this work it was found that half-lives for double β -decaying nuclides were not always consistently given in ENSDF. Since the two-neutrino ground-state-to-ground-state transition is the dominant decay mode, only those experimental half-life values, or their upper-limits, are included in NUBASE2020. In a few cases, other partial lifetime data are also compiled and these are given as comments in Table I. No attempt was made to convert the half-life values given by different authors to the same statistical confidence level (CL). The compilations by Barabash [2020Ba.A,2011Ba28] were consulted in covering such decays.

    For nuclei in their ground or excited isomeric state whose half-lives were not directly measured, values from TNN were estimates and included in Table I, whenever possible. Such cases are flagged with the symbol ‘#’.

    2.4 Spin and parity

    Spin and parity values are presented with or without parentheses, based on “weak” or “strong” arguments, respectively, as adopted in ENSDF [12], but with one important exception. Since, it is a policy of NUBASE2020 to make a clear distinction between experimental and non-experimental information, parentheses are used only when the so-called “weak” arguments are based on experimental observations. In cases where the assignments are based on theoretical predictions or TNN, the values are presented without parentheses and they are flagged with the symbol ‘#’. This is in contrast to ENSDF, where values determined from theory or systematics are given in parentheses, and as a consequence, it is not possible to distinguish these tentative values from ones determined from experimental data. It should also be noted, that despite well-defined evaluation policies [12], there are a number of inconsistencies in ENSDF regarding the spin and parity assignments. Often, the proposed spins and parities reflect the interpretation of a particular ENSDF evaluator, rather than that of firm policy rules. As a result, assignments to similar states in neighboring nuclei are put in parenthesis by one evaluator, but not by another, although similar experimental information is available.

    There is a large amount of recent experimental data on directly measured spins for nuclei far from the line of stability, where the “in-source” (e.g. RILIS at ISOLDE (CERN) and TRILIS at ISAC (TRIUMF)) and “collinear” (e.g. CRIS at ISOLDE (CERN)) laser spectroscopy techniques were deployed. In the present work, we compiled the experimentally measured spins for 1062 states (827 ground states and 235 isomers) and the corresponding values are flagged in Table I with the symbol ‘*’. We have consulted previous compilations by Fuller [13], Otten [1989Ot.A] and McDonald [14], as well as recently measured values in the literature. Figures 4 and 5 show plots of the directly measured spins for the ground and isomeric states, respectively, as a function of N and Z.

    Figure 4

    Figure 4.  Nuclear chart displaying the measured ground-state spins.
    DownLoad: Full-Size Img PowerPoint

    Figure 5

    Figure 5.  Nuclear chart displaying the measured isomeric-state spins.
    DownLoad: Full-Size Img PowerPoint

    The experimental methods that are used for spin determination do not provide direct information about the parity of a given state. However, we have used additional spectroscopy data, such as l value in transfer reactions, hindrance factors in α decay, measured magnetic moments, as well as other spectroscopic information, in order to make such assignments in Table I.

    2.5 Decay modes and their intensities

    Figure 6 displays the main ground-state decay modes for all nuclei included in Table I.

    Figure 6

    Figure 6.  Nuclear chart displaying the main decay mode for nuclei in their ground state.
    DownLoad: Full-Size Img PowerPoint

    The most important policy in assembling the information about the decay modes and their intensities was to unambiguously establish whether a particular decay is energetically allowed, but not experimentally observed (represented by a question mark alone ‘?’, e.g. ‘IT?’ or ‘ α ?’, the question mark refers to the decay mode), and whether the decay is actually observed, but its intensity is not determined (represented by ‘ =?’, e.g. ‘IT =?’ or ‘ α =?’, the question mark refers to the branching intensity).

    In cases of multiple decay modes, normalization of primary intensities to 100% was made only when the competing decays were experimentally observed. Otherwise, no such corrections were made.

    Similarly to previous versions of NUBASE [1–4], β+ denotes a decay process that includes both electron capture, ε , and positron emission, e + , decays, so that one can symbolically write β+=ε+e+ . It should be made clear that this notation is not the same as that used in ENSDF, where the combination of both modes is labeled as ε+β+ . When the available decay energy is below 2m e ≃ 1022 keV, only electron capture decay mode is allowed, while above that value the two processes are in competition. In the latter case, the separated intensities are not always experimentally available and they are frequently deduced from model calculations. Following one of the general policies of NUBASE that experimental information is exclusively used whenever possible, only measured values for β+ , ε and e+ are included in Table I. By the same token, both electron capture-delayed fission ( ε SF) and positron-delayed fission ( e+ SF) are given with the same symbol β+ SF.

    For β -delayed particle decays, intensity relations were carefully considered. By definition, the intensity of a specific β -delayed particle decay is taken as a percentage of the main β -decay mode. For example, if the decay of the (A, Z) nuclide is described as ‘ β− = 100; β− n = 20’, this means that for 100 decays of the parent, 80 (A, Z+1) and 20 (A–1, Z+1) daughter nuclei are produced and that 100 electrons and 20 delayed neutrons are emitted.

    This notation also holds for more complex β -delayed particle emissions. For example, a decay described by ‘ β− = 100; β− n = 30; β− 2n = 20; β−α = 10’ corresponds to the emission of 100 electrons, 70 (30+2 × 20) delayed-neutrons and 10 delayed- α particles; and in terms of residual nuclides, to 40 (A, Z+1), 30 (A–1, Z+1), 20 (A–2, Z+1) and 10 (A–4, Z–1), respectively.

    In general, the number of neutrons emitted per 100 β− decays, Pn , can be written as:

    Pn=∑ii×β−in;

    and similar expressions can be written for β− -delayed α and proton emissions. The number of residual daughter nuclides (A, Z+1) populated via β− decay is then:

    β−−∑iβ−in−∑jβ−jα−…

    Sometimes, the primary (parent) β decay can populate several excited states in the daughter nuclide, which can further decay by particle emission. However, in a case where the ground state of the daughter nuclide decays also by the same particle emission, some authors included its decay in the value for the corresponding β -delayed particle intensity. It is a policy of NUBASE2020 to not use such an approach for two main reasons: a) the energies of delayed particles emitted from excited states are generally much higher compared to those emitted from the ground state, thus implying different subsequent processes; b) the characteristic decay times from excited states are related to the parent, whereas decays from the daughter's ground state are connected to the daughter nuclide itself. For example, 9 C decays via β+ emission to the ground state of the proton-unbound 9 B nuclide (feeding intensity of 54.1(1.5)% [2001Be51]) and to several excited states that are proton and/or α unbound. If one takes the β+ intensities to the excited states in 9 B from Ref. [2000Ge09] and renormalizes them to per 100 decays of the parent, then β+ p = 7.5(0.6)% and β+α = 38.4(1.6)% can be determined for 9 C. In a slightly different example, 8 B decays via β+ emission only to two excited, α -unbound states in 8 Be, but not to the 8 Be ground state. Thus, one may write β+ = 100% and β+α = 100%, and therefore, no net population of the 8 Be ground state.

    It should be pointed out that the percentages given in the Table I are related to 100 decays of the parent nuclei, rather than to the primary decay mode fraction. For example, the delayed-fission probability in the decay of 228 Np is given in the original article as 0.020(9)% [1994Kr13], but this value is relative to the ε process, which has an intensity of 60(7)%. Thus, the renormalized delayed-fission intensity is 0.020(9)% × 0.60(7) = 0.012(6)% of the total decay intensity.

    In addition to applying direct updates from the literature, partial evaluations completed by other authors were also considered in the evaluation of delayed particle data. For example, in compiling data for delayed proton- and α -branching intensities, the work of Hardy and Hagberg [1989Ha.A], Jonson and Riisager [15], Blank and Borge [16] and Pfützner et al. [17], where the corresponding physics was reviewed, as well as the recent compilation of Batchelder [18], were consulted. Similarly, data on β -delayed neutron emission probabilities that were recommended by a recent IAEA Coordinated Research Project [19] were also consulted.

    2.6 Isotopic abundances

    Isotopic abundances are given in the decay field of Table I with the symbol IS and the values were taken from the most-recent publication of Meija et al. [20]. In several cases the IS values are listed in Ref. [20] as an interval [a,b] , but in Table I they are given as IS = (a+b)/2 with a variance σ 2 = (b−a)2/12 (see section 3.2).

    2.7 Year of discovery

    Similarly to the previous version of NUBASE [3, 4], Table I includes information about the year of discovery for each nuclide in its ground or isomeric state. For the former, recommendations by Thoennessen [21] were adopted. Similar criteria were used when assigning the year of discovery for isomeric states.

    2.8 References and Dissemination

    The year of the ENSDF archival file that was consulted during the development of NUBASE2020 is given in Table I. The entry is left blank when information for a particular nuclide was not available in ENSDF.

    The bibliographical information used in NUBASE2020 is referenced by means of the “Nuclear Science Reference” (NSR) database [22] keynumber style. However, references quoted in Table I are abbreviated with the first two digits of the year of publication being omitted from the NSR-style keynumbers. They are followed by up to three one-letter codes which specify the added or modified physics quantities (see the Explanation of Table I).

    In cases where more than one reference was needed to describe a particular update, they were included as comments in Table I. No references were given for estimated values.

    The initials of the former and present evaluators, e.g. GAU (G. AUDI), HWJ (W. HUANG), FGK (F. KONDEV), MMC (M. MACCORMICK), SAR (S. NAIMI) WGM (M. WANG), AHW (A. WAPSTRA), were used as reference keys where it may not be clear that the re-interpretation of data was made by the NUBASE evaluators.

    In cases of directly measured spins, references are provided only to papers that were not included in the most-recent compilation of McDonald et al. [14].

    The complete reference list is given at the end of this issue (see AME2020, Part II), together with the references used in AME2020.

    The recommended data for the basic nuclear physics properties are also made available as an ASCII-formatted file (nubase.mas20) at the dissemination websites of the collaboration [23].

    3. Policies of NUBASE2020

    3.1 Trends in neighboring nuclei (TNN)

    In general, NUBASE2020 contains numerical and bibliographical information for all known nuclei for which at least one property is experimentally known. However, it also includes results on yet unobserved nuclides, as well as data on properties (mostly excitation energy for isomers, half-lives and spins and/or parities) that are not yet measured. Such values are estimated from the systematics trends of a particular property in neighboring nuclei by ensuring a continuity in N, in Z, A, and in N−Z . This approach allowed to follow the behavior of a particular property as a function of N and Z in a consistent way and it proved beneficial in deducing values for other relevant properties. Similarly to AME2020, where masses estimated from Trends from the Mass Surface (TMS) are flagged with ‘#’, the same symbol is used in NUBASE2020 to indicate non-experimental information inferred from TNN. It should be pointed out, however, that deviations from TNN are expected when nuclear structure effects, such as deformation and/or shape changes, occur. Such data were taken into account to the best knowledge of the present authors.

    3.2 Averaging procedure and uncertainties

    It is a policy of NUBASE2020 to use one standard deviation as a representation of uncertainties associated with the recommended values. Unfortunately, authors of research articles do not always clarify the meaning of their reported uncertainties and, under such circumstances, these values are assumed to be one standard deviation. In several instances, uncertainties are not given at all and in such cases they were estimated by the evaluators, considering the limitations of the employed experimental method. When both the statistical and systematic uncertainties were reported in the literature, they were combined in a quadrature by the NUBASE2020 evaluators.

    Sometimes lower (l) and upper (u) limits of a particular quantity, q, are reported in the literature, e.g. q ∈ [l,u] . A policy of NUBASE2020 is that uniform probability distribution is assumed in such cases, which yields a mean value of m=(l+u)/2 and a standard deviation of σ = (u−l)/√12 ≃ 0.29 × (u−l) .

    When results from two or more independent measurements were reported in the literature, the corresponding values were weighted by their reported uncertainties and averaged. The weighted average value and its uncertainty are calculated as:

    ¯x±Δ¯x=N∑i=1wixi/N∑i=1wi±√1/N∑i=1wi

    		(3)

    where wi = 1/Δx2i and xi and Δxi are the value and its uncertainty reported in the ith experiment, and the summation is over all N experiments. For each average value the NORMALIZED CHI, χn (or ‘consistency factor’ or ‘Birge ratio’), defined as:

    χn=√1N−1N∑i=1wi(xi−¯x)2

    		(4)

    is also calculated.

    It is a policy of NUBASE2020 to use the weighted average result (equation 3) when χn is smaller or equal to 2.5. In cases where χn is larger than 2.5, but less or equal to 4, departure from the statistical result (equation 3) is allowed and the external uncertainty for the average value is adopted:

    ¯x±Δ¯x=N∑i=1wixi/N∑i=1wi±χn×√1/N∑i=1wi

    		(5)

    In rare cases when χn is larger than 4, all individual uncertainties are considered to be irrelevant and the arithmetic (unweighted) average is adopted:

    ¯x±Δ¯x=1NN∑i=1xi±√1N(N−1)N∑i=1(xi−¯x)2

    		(6)

    The values used in the statistical analysis of a particular quantity are given as comments in Table I. When contradictory (discrepant) results were identified in the literature, a great deal of attention was focused on establishing the reason for such discrepancies, and consequently, on rejecting (or correcting) the corresponding unreliable data prior to performing the statistical analysis. The reasons for such decisions are given as comments in Table I.

    3.3 Symmetrization of asymmetric uncertainties

    Experimental results are sometimes reported in the literature with asymmetric uncertainties, e.g. X+a−b , and it is a policy of NUBASE to symmetrize these uncertainties.

    Similarly to the previous version of NUBASE [1–4], the asymmetric uncertainty is associated with a two-piece normal distribution (sometimes called “split-normal distribution” or “Fechner distribution”), TN(X,a,b) , and the symmetrization is achieved by mapping this distribution into a normal (symmetric) distribution, N(μ,σ) , where μ is the mean value and σ is the standard deviation.

    The probability density function of a two-piece normal distribution is given as:

    f(x)={A×exp[−(x−X)2/2a2]ifx<X,A×exp[−(x−X)2/2b2]ifx<X

    		(7)

    It has a modal (most probable) value of x=X , a standard deviation b for x < X and a standard deviation a for x > X (see Figure 7), with A=(√π/2×(a+b))−1 . This distribution is formed by taking the left half of a normal distribution N(X,b) and the right half of a normal distribution N(X,a) and scaling them to give a common value of f(x) = A at the mode X (see Figure 7). The mean value and the variance of this distribution can be determined as [24]:

    Figure 7

    Figure 7.  (dashed black) original Normal distributions, N(X,b) (left on X) and N(X,a) (right on X), associated with the measured quantity X+a−b ; (solid blue) a two-piece normal distribution TN(X,a,b) ; (solid red) the equivalent Normal (symmetric) distribution, N(m,σ) ; see section 3.3 for details.
    DownLoad: Full-Size Img PowerPoint

    μ=X+√2/π×(a−b)

    		(8)

    σ2=(1−2/π)×(a−b)2+a×b

    		(9)

    The median value m, which divides the distribution into two equal areas is then:

    m={X+a√2×erf−1(a−b2a)ifa<b,X+b√2×erf−1(a−b2b)ifb<a.

    		(10)

    If one takes erf−1(z)≃√πz/2 then

    m−X≃√π/8×(a−b)≃0.6267×(a−b)

    		(11)

    In order to allow for a small non-linearity that appears for high values of m−X , equation 11 is modified to:

    m≃X+0.64×(a−b)

    		(12)

    Following the above approach, the two-piece normal distribution TN(X,a,b) is mapped into an equivalent normal (symmetric) distribution N(m, σ ) (see Figure 7) that have a mean value equal to the median value m (equation 12) and variance σ (equation 9). As a consequence, X+a−b is symmetrized to m ± σ and the latter is adopted in NUBASE2020.

    3.4 Rounding policy

    In general, values for properties presented in NUBASE2020 and their uncertainties are rounded off, even if unrounded ones were given in the literature or in ENSDF. However, for some very precise data, as well as for data that were deemed essential for traceability purposes (e.g. isotopic abundances), the precisions quoted in the original publications were retained.

    In cases where the two furthest-left significant digits in the uncertainty were larger than a given limit (set to 30 for the mass excess and excitation energy of isomers in order to be consistent with AME, and set to 25 for half-lives and branching ratios, as generally used in ENSDF), the adopted values and corresponding uncertainties were rounded off accordingly.

    4. Conclusions and outlook

    The NUBASE2020 evaluated nuclear data library contains the recommended values for the basic nuclear physics properties for all known nuclei, such as mass excess, excitation energy of the excited isomeric state, half-life, spin and parity, decay modes and their intensities, isotopic abundance (for stable nuclides), year of discovery, as well as the corresponding bibliographical information. It also contains information for yet unobserved nuclei whose properties were estimated by following the systematic trends in neighboring nuclei.

    One of the main requirements in the development of NUBASE2020 was to cover the available experimental data as completely as possible and to provide proper references to all experimental results, especially for cases that are not included in ENSDF or in other topical evaluations. Such a traceability would allow any user to promptly review the recommended data and, if necessary, to undertake a re-evaluation.

    NUBASE2020 is an integral part of AME2020 and the synchronization of these two libraries allows better homogeneity of all experimental data to be achieved. Furthermore, assignments of isomeric states and determination of their excitation energies were put on a firm basis and the data were improved.

    In the future development of NUBASE, it is envisioned to include additional nuclear properties, such as magnetic and quadrupole moments, charge-radii and isotope shifts, cross sections of importance to nuclear astrophysics applications, as well as additional decay properties of relevance to energy and non-energy applications, in order to better serve the broader nuclear physics community.

    5. Acknowledgments

    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) and in part by the National Key Research and Development Program of China (Grant No. 2016YFA0400504) and 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.

    We thank many colleagues who responded to our queries about the experimental data, as well as those who sent us preprints of their work prior publication. We also thank D. Lunney and B. Kay for the careful reading of the manuscript and useful comments.

    References

    [1] G. Audi, O. Bersillon, J. Blachot and A.H. Wapstra, Nucl. Phys. A 624, 1 (1997 doi: 10.1016/S0375-9474(97)00482-X
    [2] G. Audi, O. Bersillon, J. Blachot and A.H. Wapstra, Nucl. Phys. A 729, 3 (2003 doi: 10.1016/j.nuclphysa.2003.11.001
    [3] G. Audi, F.G. Kondev, M. Wang, B. Pfeiffer, X. Sun, J. Blachot and M. MacCormick, Chin. Phys. C 36, 12 (2012
    [4] G. Audi, F.G. Kondev, M. Wang, W.J. Huang, S. Naimi, Chin. Phys. C 41, 03001 (2017
    [5] T.W. Burrows, Nucl. Instrum. Meth. 286 (1990) 595; http://www.nndc.bnl.gov/ensdf/
    [6] F.G. Kondev, G.D. Dracoulis, T. Kibédi, At. Data Nucl. Data Tables 103-104 (2015) 50; F.G. Kondev, G.D. Dracoulis, T. Kibédi, At. Data Nucl. Data Tables 105-106 (2015) 105 (erratum)
    [7] G.D. Dracoulis, P.M. Walker, F.G. Kondev, Rep. Prog. Phys. 79, 076301 (2016 doi: 10.1088/0034-4885/79/7/076301
    [8] M. MacCormick and G. Audi, Nucl. Phys. A 925, 61 (2014 doi: 10.1016/j.nuclphysa.2014.01.007
    [9] Y.H. Lama, B. Blank, N.A. Smirnova, J.B. Bueb, and M.S. Antony, At. Data Nucl. Data Tables 99, 680 (2013 doi: 10.1016/j.adt.2012.11.002
    [10] M.P. Unterweger and R. Fitzgerald, Appl. Radiat. Isot. 159, 108976 (2020 doi: 10.1016/j.apradiso.2019.108976
    [11] M.P. Unterweger and R. Fitzgerald, Appl. Radiat. Isot. 87, 92 (2014 doi: 10.1016/j.apradiso.2013.11.017
    [12] General Policies, Nucl. Data Sheets 164, 478 (2020 doi: 10.1016/j.nds.2020.01.002
    [13] G.H. Fuller, J. Phys. Chem. Ref. Data 5, 835 (1976 doi: 10.1063/1.555544
    [14] A. MacDonald, B. Karamy, K. Setoodehnia, B.Singh, Nucl. Data Sheets 114, 397 (2013 doi: 10.1016/j.nds.2013.03.002
    [15] B. Jonson and K. Riisager, Nucl. Phys. A 693, 77 (2001 doi: 10.1016/S0375-9474(00)00560-1
    [16] B. Blank and M. Borge, Prog. Part. Nucl. Phys. 60, 403 (2008 doi: 10.1016/j.ppnp.2007.12.001
    [17] M. Pfützner, M. Karny, L.V. Grigorenko, K. Riisager, Rev. Mod. Phys. 84, 567 (2012 doi: 10.1103/RevModPhys.84.567
    [18] J.C. Batchelder, At. Data Nucl. Data Tables 132, 101323 (2020 doi: 10.1016/j.adt.2019.101323
    [19] IAEA Coordinated Research Project on a reference database for beta-delayed neutron emission; https://www-nds.iaea.org/beta-delayed-neutron/; M. Birch, B. Singh, I. Dillmann, D. Abriola, T.D. Johnson, E.A. McCutchan, and A.A. Sonzogni, Nucl. Data Sheets 128 (2015) 131; J. Liang, B. Singh, E.A. McCutchan, I. Dillmann, M. Birch, A.A. Sonzogni, X. Huang, M. Kang, J. Wang, G. Mukherjee, K. Banerjee, D. Abriola, A. Algora, A.A. Chen, T.D. Johnson, and K. Miernik, Nucl. Data Sheets168 (2020) 1.
    [20] J. Meija, T.B. Coplen, M. Berglund, W.A. Brand, P. De Bièvre, M. Gröning, N.E. Holden, J. Irrgeher, R.D. Loss, T. Walczyk and T. Prohaska, Pure Appl. Chem. 88(3), 293 (2016 doi: 10.1515/pac-2015-0503
    [21] M. Thoennessen, “The Discovery of Isotopes: A Complete Compilation”, Springer International Publishing Switzerland 2016; https://people.nscl.msu.edu/thoennes/isotopes/
    [22] B. Pritychenko, E. Běták, M.A. Kellett, B. Singh and J. Totans, Nucl. Instrum. Methods Phys. Res. A640 (2011) 213; http://www.nndc.bnl.gov/nsr/
    [23] The NUBASE2020 files in electronic-distribution format and additional complementary information can be retrieved from the main dissemination websities of the present collaboration: IMP at http://amdc.impcas.ac.cn/; ANL at https://www.anl.gov/phy/atomic-mass-dataresources; IAEA at https://www-nds.iaea.org/amdc/
    [24] S. John, Comun. Statist. -Theor. Meth. 11(8), 879 (1982 doi: 10.1080/03610928208828279

  • References

    [1] G. Audi, O. Bersillon, J. Blachot and A.H. Wapstra, Nucl. Phys. A 624, 1 (1997 doi: 10.1016/S0375-9474(97)00482-X
    [2] G. Audi, O. Bersillon, J. Blachot and A.H. Wapstra, Nucl. Phys. A 729, 3 (2003 doi: 10.1016/j.nuclphysa.2003.11.001
    [3] G. Audi, F.G. Kondev, M. Wang, B. Pfeiffer, X. Sun, J. Blachot and M. MacCormick, Chin. Phys. C 36, 12 (2012
    [4] G. Audi, F.G. Kondev, M. Wang, W.J. Huang, S. Naimi, Chin. Phys. C 41, 03001 (2017
    [5] T.W. Burrows, Nucl. Instrum. Meth. 286 (1990) 595; http://www.nndc.bnl.gov/ensdf/
    [6] F.G. Kondev, G.D. Dracoulis, T. Kibédi, At. Data Nucl. Data Tables 103-104 (2015) 50; F.G. Kondev, G.D. Dracoulis, T. Kibédi, At. Data Nucl. Data Tables 105-106 (2015) 105 (erratum)
    [7] G.D. Dracoulis, P.M. Walker, F.G. Kondev, Rep. Prog. Phys. 79, 076301 (2016 doi: 10.1088/0034-4885/79/7/076301
    [8] M. MacCormick and G. Audi, Nucl. Phys. A 925, 61 (2014 doi: 10.1016/j.nuclphysa.2014.01.007
    [9] Y.H. Lama, B. Blank, N.A. Smirnova, J.B. Bueb, and M.S. Antony, At. Data Nucl. Data Tables 99, 680 (2013 doi: 10.1016/j.adt.2012.11.002
    [10] M.P. Unterweger and R. Fitzgerald, Appl. Radiat. Isot. 159, 108976 (2020 doi: 10.1016/j.apradiso.2019.108976
    [11] M.P. Unterweger and R. Fitzgerald, Appl. Radiat. Isot. 87, 92 (2014 doi: 10.1016/j.apradiso.2013.11.017
    [12] General Policies, Nucl. Data Sheets 164, 478 (2020 doi: 10.1016/j.nds.2020.01.002
    [13] G.H. Fuller, J. Phys. Chem. Ref. Data 5, 835 (1976 doi: 10.1063/1.555544
    [14] A. MacDonald, B. Karamy, K. Setoodehnia, B.Singh, Nucl. Data Sheets 114, 397 (2013 doi: 10.1016/j.nds.2013.03.002
    [15] B. Jonson and K. Riisager, Nucl. Phys. A 693, 77 (2001 doi: 10.1016/S0375-9474(00)00560-1
    [16] B. Blank and M. Borge, Prog. Part. Nucl. Phys. 60, 403 (2008 doi: 10.1016/j.ppnp.2007.12.001
    [17] M. Pfützner, M. Karny, L.V. Grigorenko, K. Riisager, Rev. Mod. Phys. 84, 567 (2012 doi: 10.1103/RevModPhys.84.567
    [18] J.C. Batchelder, At. Data Nucl. Data Tables 132, 101323 (2020 doi: 10.1016/j.adt.2019.101323
    [19] IAEA Coordinated Research Project on a reference database for beta-delayed neutron emission; https://www-nds.iaea.org/beta-delayed-neutron/; M. Birch, B. Singh, I. Dillmann, D. Abriola, T.D. Johnson, E.A. McCutchan, and A.A. Sonzogni, Nucl. Data Sheets 128 (2015) 131; J. Liang, B. Singh, E.A. McCutchan, I. Dillmann, M. Birch, A.A. Sonzogni, X. Huang, M. Kang, J. Wang, G. Mukherjee, K. Banerjee, D. Abriola, A. Algora, A.A. Chen, T.D. Johnson, and K. Miernik, Nucl. Data Sheets168 (2020) 1.
    [20] J. Meija, T.B. Coplen, M. Berglund, W.A. Brand, P. De Bièvre, M. Gröning, N.E. Holden, J. Irrgeher, R.D. Loss, T. Walczyk and T. Prohaska, Pure Appl. Chem. 88(3), 293 (2016 doi: 10.1515/pac-2015-0503
    [21] M. Thoennessen, “The Discovery of Isotopes: A Complete Compilation”, Springer International Publishing Switzerland 2016; https://people.nscl.msu.edu/thoennes/isotopes/
    [22] B. Pritychenko, E. Běták, M.A. Kellett, B. Singh and J. Totans, Nucl. Instrum. Methods Phys. Res. A640 (2011) 213; http://www.nndc.bnl.gov/nsr/
    [23] The NUBASE2020 files in electronic-distribution format and additional complementary information can be retrieved from the main dissemination websities of the present collaboration: IMP at http://amdc.impcas.ac.cn/; ANL at https://www.anl.gov/phy/atomic-mass-dataresources; IAEA at https://www-nds.iaea.org/amdc/
    [24] S. John, Comun. Statist. -Theor. Meth. 11(8), 879 (1982 doi: 10.1080/03610928208828279

  • Access

    加载中

Cited by

1. Alsultan, T.Y.T., Majekodunmi, J.T., Kumar, R. et al. Impact of nuclear rotation corrections on alpha decay half-lives of superheavy nuclei within 98 ≤ Z ≤ 120[J]. Nuclear Physics A, 2024. doi: 10.1016/j.nuclphysa.2023.122784
2. Nabi, J.-U., Ullah, A., Iqbal, M. Energy rates due to Fe isotopes during presupernova evolution of massive stars[J]. New Astronomy, 2024. doi: 10.1016/j.newast.2023.102114
3. Pakulla, J.J., Mike, J.W., Raymond, D.A. et al. Trace element and Sr-Nd-Hf-Pb isotope evidence for a multi-magma chamber system beneath the Deccan Volcanic Province, India[J]. Chemical Geology, 2023. doi: 10.1016/j.chemgeo.2023.121749
4. L., R.R., Anushree, H.S. et al. Improved semi-empirical formulae for Beta-decay[J]. Physics Open, 2023. doi: 10.1016/j.physo.2023.100187
5. Krasta, T., Manika, I., Kuzmin, A. et al. Effect of ion-induced secondary radiations on the formation of extended defects and radiolysis beyond the range of swift 12C, 50Ti, and 52Cr ions in LiF[J]. Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms, 2023. doi: 10.1016/j.nimb.2023.165142
6. Nesterenko, D.A., Ruotsalainen, J., Stryjczyk, M. et al. High-precision measurements of low-lying isomeric states in In 120-124 with the JYFLTRAP double Penning trap[J]. Physical Review C, 2023, 108(5): 054301. doi: 10.1103/PhysRevC.108.054301
7. Jaries, A., Stryjczyk, M., Kankainen, A. et al. Precision mass measurement of 173 Hf for nuclear structure of 173 Lu and the γ process[J]. European Physical Journal A, 2023, 59(11): 263. doi: 10.1140/epja/s10050-023-01176-4
8. Yazdankish, E., Nejatolahi, M. Improved calculation of alpha decay half-life by incorporating nuclei deformation shape and proximity potential[J]. Physica Scripta, 2023, 98(11): 115309. doi: 10.1088/1402-4896/acfe52
9. Qi, L.-J., Zhang, D.-M., Luo, S. et al. Cluster radioactivity half-lives of trans-lead nuclei with a statistical physical preformation factor[J]. European Physical Journal A, 2023, 59(11): 255. doi: 10.1140/epja/s10050-023-01162-w
10. Santhosh, K.P., Anjali, V.K. Systematic studies on α decay of Po, At, Rn, Fr and Ra using modified generalized liquid drop model[J]. European Physical Journal A, 2023, 59(10): 248. doi: 10.1140/epja/s10050-023-01164-8
11. Kiselyova, S.S., Petrov, V.G. Sorption of Zirconium on Quartz[J]. Physics of Particles and Nuclei Letters, 2023, 20(5): 1263-1265. doi: 10.1134/S1547477123050436
12. Alsultan, T.Y.T., Majekodunmi, J.T., Kumar, R. et al. Study of Rotational Effect on Even-Even 254,256Rf Isotopes of α-Particle Radioactivity Using Various Semi-Empirical Formulae[J]. Physics of Particles and Nuclei Letters, 2023, 20(5): 969-975. doi: 10.1134/S1547477123050059
13. Deng, D., Ren, Z., Wang, N. Unusual behavior in the systematics of α -preformation factors above Z, N= 50 doubly magic shell closures[J]. European Physical Journal A, 2023, 59(10): 226. doi: 10.1140/epja/s10050-023-01138-w
14. Parker, M.C., Jeynes, C. Ab Initio Thermodynamics Calculation of Beta Decay Rates[J]. Annalen der Physik, 2023, 535(10): 2300259. doi: 10.1002/andp.202300259
15. Anjali, V.K., Santhosh, K.P. α decay half-lives of nuclei W, Re, Os, Ir and Pt in the range 157≤A≤193 using the modified generalised liquid drop model (MGLDM)[J]. Physica Scripta, 2023, 98(10): 105303. doi: 10.1088/1402-4896/acf34d
16. Singh, B., Chen, J. Nuclear Structure and Decay Data for A=167 Isobars[J]. Nuclear Data Sheets, 2023. doi: 10.1016/j.nds.2023.08.001
17. Tavares, O.A.P., Terranova, M.L. Physical viability for nuclear batteries[J]. Journal of Radioanalytical and Nuclear Chemistry, 2023, 332(10): 3933-3942. doi: 10.1007/s10967-023-09034-9
18. Suescún-Díaz, D., Ibáñez-Paredes, M.C., Chala-Casanova, J.A. Stochastic radioactive decay[J]. Physica A: Statistical Mechanics and its Applications, 2023. doi: 10.1016/j.physa.2023.129109
19. Huang, W.J., Zhou, X., Zhang, Y.H. et al. Ground-state mass of the odd-odd N=Z nuclide Br 70[J]. Physical Review C, 2023, 108(3): 034301. doi: 10.1103/PhysRevC.108.034301
20. Liu, X., Jiang, J.-D., Qi, L.-J. et al. Systematic calculations of cluster radioactivity half-lives with a screened electrostatic barrier[J]. Chinese Physics C, 2023, 47(9): 094103. doi: 10.1088/1674-1137/ace351
21. Cui, T., Yang, Y. Yield calculation for delayed gamma-ray neutron activation analysis[J]. Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2023. doi: 10.1016/j.nima.2023.168380
22. Gharaei, R., Jalali Shakib, M., Santhosh, K.P. Description of temperature effects on proton radioactivity[J]. Nuclear Physics A, 2023. doi: 10.1016/j.nuclphysa.2023.122700
23. Rodrigo, A., Otuka, N., Takács, S. et al. Compilation of isomeric ratios of light particle induced nuclear reactions[J]. Atomic Data and Nuclear Data Tables, 2023. doi: 10.1016/j.adt.2023.101583
24. Bonnard, J., Dobaczewski, J., Danneaux, G. et al. Nuclear DFT electromagnetic moments in heavy deformed open-shell odd nuclei[J]. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2023. doi: 10.1016/j.physletb.2023.138014
25. Oganessian, Y.T., Utyonkov, V.K., Shumeiko, M.V. et al. New isotope Ds 276 and its decay products Hs 272 and Sg 268 from the Th 232 + Ca 48 reaction[J]. Physical Review C, 2023, 108(2): 024611. doi: 10.1103/PhysRevC.108.024611
26. Zhang, D.-M., Qi, L.-J., Gui, H.-F. et al. Analytic formula for the proton radioactivity spectroscopic factor[J]. Physical Review C, 2023, 108(2): 024318. doi: 10.1103/PhysRevC.108.024318
27. Seif, W.M., Abdulghany, A.R. Stability and α decay of translead isomers and the related preformation probability of α particles[J]. Physical Review C, 2023, 108(2): 024308. doi: 10.1103/PHYSREVC.108.024308
28. Hartley, D.J., Kondev, F.G., Carpenter, M.P. et al. First β-decay spectroscopy study of 157Nd[J]. Physical Review C, 2023, 108(2): 024307. doi: 10.1103/PhysRevC.108.024307
29. Li, W., Zhang, X., Niu, Z. Studies of nuclear β-decay half-lives with Bayesian neural network approach | [贝叶斯神经网络方法对原子核 β 衰变寿命的研究][J]. He Jishu/Nuclear Techniques, 2023, 46(8): 080013. doi: 10.11889/j.0253-3219.2023.hjs.46.080013
30. Shao, L.. Optimization of Deuteron Irradiation of 176Yb for Producing 177Lu of High Specific Activity Exceeding 3000 GBq/mg[J]. Molecules, 2023, 28(16): 6053. doi: 10.3390/molecules28166053
31. Saxena, G., Jain, A. Cluster radioactivity from trans-tin to superheavy region using an improved empirical formula[J]. European Physical Journal A, 2023, 59(8): 189. doi: 10.1140/epja/s10050-023-01102-8
32. Wang, Z., Ren, Z. Effects of nuclear surface polarization on exotic cluster radioactivity in trans-lead nuclei[J]. Physical Review C, 2023, 108(2): 024306. doi: 10.1103/PhysRevC.108.024306
33. Borzov, I.N.. Self-Consistent Study of the Ground State and β-Decay Properties in C, N, O Region[J]. Physics of Particles and Nuclei, 2023, 54(4): 581-585. doi: 10.1134/S1063779623040093
34. Nabi, J.-U., Bayram, T., Riaz, M. et al. Re-examination of β-decay in Hg, Pb and Po Isotopes[J]. Physica Scripta, 2023, 98(8): 085314. doi: 10.1088/1402-4896/ace80b
35. Xiao, Q., Cheng, J.-H., Wang, B.-L. et al. Half-lives for proton emission and α decay within the deformed Gamow-like model[J]. Journal of Physics G: Nuclear and Particle Physics, 2023, 50(8): 085102. doi: 10.1088/1361-6471/acdfeb
36. Chen, J., Singh, B. Nuclear Structure and Decay Data for A=44 Isobars[J]. Nuclear Data Sheets, 2023. doi: 10.1016/j.nds.2023.06.001
37. Jain, A., Sharma, P.K., Jain, S.K. et al. Decay properties of undetected superheavy nuclei with Z > 110[J]. Physica Scripta, 2023, 98(8): 085304. doi: 10.1088/1402-4896/ace00d
38. He, W., Li, Q., Ma, Y. et al. Machine learning in nuclear physics at low and intermediate energies[J]. Science China: Physics, Mechanics and Astronomy, 2023, 66(8): 282001. doi: 10.1007/s11433-023-2116-0
39. Kullmann, I., Goriely, S., Just, O. et al. Impact of systematic nuclear uncertainties on composition and decay heat of dynamical and disc ejecta in compact binary mergers[J]. Monthly Notices of the Royal Astronomical Society, 2023, 523(2): 2551-2576. doi: 10.1093/mnras/stad1458
40. Zhou, X., Wang, M., Zhang, Y.H. et al. Mass measurements show slowdown of rapid proton capture process at waiting-point nucleus 64Ge[J]. Nature Physics, 2023, 19(8): 1091-1097. doi: 10.1038/s41567-023-02034-2
41. Liu, Z.X., Lam, Y.H., Lu, N. et al. The optimized point-coupling interaction for the relativistic energy density functional of Hartree-Bogoliubov approach quantifying the nuclear bulk properties[J]. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2023. doi: 10.1016/j.physletb.2023.137946
42. Pahlavani, M.R., Ahmadvand, F. Study of α -decay half-life for axially symmetric deformed even-even isotopes of nuclei with atomic numbers 8 8 ≤ Z ≤ 1 0 4[J]. International Journal of Modern Physics E, 2023, 32(7): 2350036. doi: 10.1142/S0218301323500362
43. Qi, L.-J., Zhang, D.-M., Luo, S. et al. Cluster radioactivity preformation probability of trans-lead nuclei in the NpNn scheme[J]. Physical Review C, 2023, 108(1): 014325. doi: 10.1103/PhysRevC.108.014325
44. Scharl, K., Ding, S., Holthoff, G. et al. Setup for the Ionic Lifetime Measurement of the 229mTh3+ Nuclear Clock Isomer[J]. Atoms, 2023, 11(7): 108. doi: 10.3390/atoms11070108
45. Holmbeck, E.M., Surman, R., Roederer, I.U. et al. HD 222925: A New Opportunity to Explore the Astrophysical and Nuclear Conditions of r-process Sites[J]. Astrophysical Journal, 2023, 951(1): 30. doi: 10.3847/1538-4357/acccf3
46. Turkat, S., Mougeot, X., Singh, B. et al. Systematics of logft values for β−, and EC/β＋transitions[J]. Atomic Data and Nuclear Data Tables, 2023. doi: 10.1016/j.adt.2023.101584
47. Denisov, V.Y.. Pre-neutron emission average total kinetic energy of fission fragments[J]. Atomic Data and Nuclear Data Tables, 2023. doi: 10.1016/j.adt.2023.101582
48. Svetlichnyi, A., Savenkov, S., Nepeivoda, R. et al. Clustering in Oxygen Nuclei and Spectator Fragments in 16O–16O Collisions at the LHC[J]. Physics (Switzerland), 2023, 5(2): 381-390. doi: 10.3390/physics5020027
49. Luo, S., Qi, L.-J., Zhang, D.-M. et al. An improved empirical formula of α decay half-lives for superheavy nuclei[J]. European Physical Journal A, 2023, 59(6): 125. doi: 10.1140/epja/s10050-023-01040-5
50. Koning, A., Hilaire, S., Goriely, S. TALYS: modeling of nuclear reactions[J]. European Physical Journal A, 2023, 59(6): 131. doi: 10.1140/epja/s10050-023-01034-3
51. Qi, L.-J., Zhang, D.-M., Luo, S. et al. New Geiger-Nuttall law for cluster radioactivity half-lives[J]. Chinese Physics C, 2023, 47(6): 064107. doi: 10.1088/1674-1137/accc78
52. Majekodunmi, J.T., Alsultan, T.Y.T., Anwar, K. et al. The α-particle clustering and half-lives of the newly discovered 207,208Th decay chains within relativistic-Hartree-Bogoliubov approach[J]. Nuclear Physics A, 2023. doi: 10.1016/j.nuclphysa.2023.122652
53. Wang, M., Zhang, Y.H., Zhou, X. et al. Mass Measurement of Upper fp -Shell N=Z-2 and N=Z-1 Nuclei and the Importance of Three-Nucleon Force along the N=Z Line[J]. Physical Review Letters, 2023, 130(19): 192501. doi: 10.1103/PhysRevLett.130.192501
54. Pomorski, K., Nerlo-Pomorska, B., Schmitt, C. et al. Fourier-over-spheroid shape parametrization applied to nuclear fission dynamics[J]. Physical Review C, 2023, 107(5): 054616. doi: 10.1103/PhysRevC.107.054616
55. Litvinov, Y.A., Chen, R.J. Radioactive decays of stored highly charged ions[J]. European Physical Journal A, 2023, 59(5): 102. doi: 10.1140/epja/s10050-023-00978-w
56. Hila, F.C., Jecong, J.F.M., Dingle, C.A.M. et al. ENDF/B-VIII.0-based fast neutron removal cross sections database in Z = 1 to 92 generated via multi-layered spherical geometry[J]. Radiation Physics and Chemistry, 2023. doi: 10.1016/j.radphyschem.2023.110770
57. Nasrudin, D., Rochman, C., Putra, R.P. et al. Improving people's energy literacy through the nuclear energy web[J]. AIP Conference Proceedings, 2023. doi: 10.1063/5.0114561
58. Mollaebrahimi, A., Hornung, C., Dickel, T. et al. Studying Gamow-Teller transitions and the assignment of isomeric and ground states at N = 50[J]. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2023. doi: 10.1016/j.physletb.2023.137833
59. Venczel, M., Veress, Á., Szentmiklósi, L. et al. Dynamic Thermal Neutron Radiography for Filling Process Analysis and CFD Model Validation of Visco-Dampers[J]. Machines, 2023, 11(4): 485. doi: 10.3390/machines11040485
60. Zhang, D.-M., Qi, L.-J., Zhu, D.-X. et al. Systematic study on the proton radioactivity of spherical proton emitters[J]. Nuclear Science and Techniques, 2023, 34(4): 55. doi: 10.1007/s41365-023-01201-7
61. Nichols, A.L., Dimitriou, P., Algora, A. et al. Improving fission-product decay data for reactor applications: part I—decay heat[J]. European Physical Journal A, 2023, 59(4): 78. doi: 10.1140/epja/s10050-023-00969-x
62. Singh, B., Chen, J. Nuclear Structure and Decay Data for A=71 Isobars[J]. Nuclear Data Sheets, 2023. doi: 10.1016/j.nds.2023.02.001
63. Şekerci̇, M., Özdoğan, H., Kaplan, A. A study on the cross-section data of 43,44m,46,47Sc isotopes via (d,x) reactions on natural abundance targets under the effects of deuteron optical models[J]. Applied Radiation and Isotopes, 2023. doi: 10.1016/j.apradiso.2023.110714
64. Chiera, N.M., Dressler, R., Sprung, P. et al. Determination of the half-life of gadolinium-148[J]. Applied Radiation and Isotopes, 2023. doi: 10.1016/j.apradiso.2023.110708
65. Ullah, A., Nabi, J.-U., Tahir, M. Investigation of Effects of Pairing Correlations on Calculated β -Decay Half-lives of fp-Shell Nuclei[J]. Brazilian Journal of Physics, 2023, 53(2): 39. doi: 10.1007/s13538-022-01236-y
66. Khalaf, S.A.J., Ridha, A.R. Properties of Ground-State of 17,19,20,24,26F using the Wave Functions of Harmonic-Oscillator and Spherical Hankel Functions[J]. Iraqi Journal of Science, 2023, 64(2): 668-675. doi: 10.24996/ijs.2023.64.2.16
67. Denisov, V.Y.. Simple expressions for calculation of proximity interaction of arbitrarily oriented deformed nuclei[J]. International Journal of Modern Physics E, 2023, 32(1): 2350005. doi: 10.1142/S0218301323500052
68. Pradeep Kumar, K., Santhosh, K.P. Synthesis of superheavy elements[J]. Pramana - Journal of Physics, 2023, 97(1): 47. doi: 10.1007/s12043-023-02517-0
69. Vasanthi, L., Rajeswari, N.S. Nuclear surface diffuseness in cluster decay[J]. Pramana - Journal of Physics, 2023, 97(1): 41. doi: 10.1007/s12043-022-02510-z
70. Jain, A., Sharma, P.K., Jain, S.K. et al. Cluster radioactivity in trans-lead region: A systematic study with modified empirical formulas[J]. Nuclear Physics A, 2023. doi: 10.1016/j.nuclphysa.2022.122597
71. Chandran, M., Santhosh, K.P. α and 2α decay of nuclei in the region 94≤Z≤101 using the modified generalized liquid drop model[J]. Physical Review C, 2023, 107(2): 024614. doi: 10.1103/PhysRevC.107.024614
72. Xu, Y.-Y., Hu, X.-Y., Zhu, D.-X. et al. Systematic study of proton radioactivity half-lives[J]. Nuclear Science and Techniques, 2023, 34(2): 30. doi: 10.1007/s41365-023-01178-3
73. Holmbeck, E.M., Sprouse, T.M., Mumpower, M.R. Nucleosynthesis and observation of the heaviest elements[J]. European Physical Journal A, 2023, 59(2): 28. doi: 10.1140/epja/s10050-023-00927-7
74. Zhang, M., Zhou, X., Wang, M. et al. Bρ -defined isochronous mass spectrometry and mass measurements of 58 Ni fragments[J]. European Physical Journal A, 2023, 59(2): 27. doi: 10.1140/epja/s10050-023-00928-6
75. Goriely, S.. Nuclear properties for nuclear astrophysics studies[J]. European Physical Journal A, 2023, 59(2): 16. doi: 10.1140/epja/s10050-023-00931-x
76. Chen, J., Fang, J.Y., Hao, Y.W. et al. Impact of Nuclear β-decay Half-life Uncertainties on the r-process Simulations[J]. Astrophysical Journal, 2023, 943(2): 102. doi: 10.3847/1538-4357/acaeab
77. Kondev, F.G.. Nuclear Data Sheets for A=201[J]. Nuclear Data Sheets, 2023. doi: 10.1016/j.nds.2023.01.003
78. Jia, J., Li, H., Dong, C. Shell-model Study of Two-neutrino Double-Beta Decay for Z = 40-50 Nuclei and their SSD Properties[J]. Physica Scripta, 2023, 98(2): 025301. doi: 10.1088/1402-4896/acadb6
79. Yuan, Z., Bai, D., Wang, Z. et al. Research on two-proton radioactivity in density-dependent cluster model[J]. Science China: Physics, Mechanics and Astronomy, 2023, 66(2): 222012. doi: 10.1007/s11433-022-1994-8
80. Letourneau, A., Savu, V., Lhuillier, D. et al. Origin of the Reactor Antineutrino Anomalies in Light of a New Summation Model with Parametrized β- Transitions[J]. Physical Review Letters, 2023, 130(2): 021801. doi: 10.1103/PhysRevLett.130.021801
81. Chuvilskaya, T.V.. High-spin isomers production in (α,n)-reactions[J]. Journal of Physics: Conference Series, 2023, 2586(1): 012051. doi: 10.1088/1742-6596/2586/1/012051
82. Ly, N.D., Duy, N.N., Uyen, N.K. et al. BETA-DECAY HALF-LIFE UNCERTAINTY OF THE EXTREMELY NEUTRON-RICH NUCLEI DUE TO NUCLEAR-MASS DEVIATION[J]. Acta Physica Polonica B, 2023, 54(8): 8-A3. doi: 10.5506/APhysPolB.54.8-A3
83. Belhaddouf, R., Oudih, M.R., Fellah, M. et al. Alpha decay and cluster radioactivity investigation of actinide nuclei[J]. International Journal of Modern Physics E, 2023. doi: 10.1142/S021830132350043X
84. Hameed, A.M., Ridha, A.R. Ground State Structure of Helium and Phosphorus Isotopes using the Radial Wave Functions of Harmonic-Oscillator and Hulthen Potentials[J]. Iraqi Journal of Science, 2023, 64(5): 2250-2260. doi: 10.24996/ijs.2023.64.5.13
85. Verma, D.S., Vivek, Kushmakshi Bulk and neutron–proton asymmetry coefficients of the semi-empirical mass formula tuned to ground state mass excess of AME2020 and/or FRDM(2012)[J]. Atomic Data and Nuclear Data Tables, 2023. doi: 10.1016/j.adt.2023.101619
86. Tavares, O.A.P., Terranova, M.L. A semiempirical evaluation of half-life of 146 Sm isotope[J]. Modern Physics Letters A, 2023. doi: 10.1142/S0217732323501158
87. Mumpower, M., Li, M., Sprouse, T.M. et al. Bayesian averaging for ground state masses of atomic nuclei in a Machine Learning approach[J]. Frontiers in Physics, 2023. doi: 10.3389/fphy.2023.1198572
88. Pomorski, K., Nerlo-Pomorska, B. FISSION FRAGMENTS MASS YIELDS OF ACTINIDE NUCLEI[J]. Acta Physica Polonica B, Proceedings Supplement, 2023, 14(6): 4-A21. doi: 10.5506/APhysPolBSupp.16.4-A21
89. Hukkanen, M., Ryssens, W., Ascher, P. et al. Odd-odd neutron-rich rhodium isotopes studied with the double Penning trap JYFLTRAP[J]. Physical Review C, 2023, 107(1): 014306. doi: 10.1103/PhysRevC.107.014306
90. Ma, N.-N., Zhao, T.-L., Wang, W.-X. et al. Simple deep-learning approach for α -decay half-life studies[J]. Physical Review C, 2023, 107(1): 014310. doi: 10.1103/PhysRevC.107.014310
91. Göbel, M., Acharya, B., Hammer, H.-W. et al. Final-state interactions and spin structure in E1 breakup of Li 11 in halo effective field theory[J]. Physical Review C, 2023, 107(1): 014617. doi: 10.1103/PhysRevC.107.014617
92. Xing, Y.M., Yuan, C.X., Wang, M. et al. Isochronous mass measurements of neutron-deficient nuclei from Sn 112 projectile fragmentation[J]. Physical Review C, 2023, 107(1): 014304. doi: 10.1103/PhysRevC.107.014304
93. Candela, V., Cavallini, C., Gasparrini, C. et al. Investigations on Caesium Dispersion and Molybdenum Coating on SPIDER Components[J]. Materials, 2023, 16(1): 206. doi: 10.3390/ma16010206
94. Qi, L.-J., Zhang, D.-M., Luo, S. et al. Systematic calculations of cluster radioactivity half-lives in trans-lead nuclei[J]. Chinese Physics C, 2023, 47(1): 014101. doi: 10.1088/1674-1137/ac94bd
95. Denisov, V.Y.. Estimation of the double alpha-decay half-life[J]. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2022. doi: 10.1016/j.physletb.2022.137569
96. He, C., Guo, J.-Y. Structure and α decay for the neutron-deficient nuclei with 89≤Z≤94 in the density-dependent cluster model combined with a relativistic mean-field approach[J]. Physical Review C, 2022, 106(6): 064310. doi: 10.1103/PhysRevC.106.064310
97. Wu, J., Nishimura, S., Söderström, P.-A. et al. First observation of isomeric states in Zr 111, Nb 113, and Mo 115[J]. Physical Review C, 2022, 106(6): 064328. doi: 10.1103/PhysRevC.106.064328
98. Mumpower, M.R., Kawano, T., Sprouse, T.M. β- -delayed fission in the coupled quasiparticle random-phase approximation plus Hauser-Feshbach approach[J]. Physical Review C, 2022, 106(6): 065805. doi: 10.1103/PhysRevC.106.065805
99. Lalkovski, S., Kisyov, S. Evolution of the j-1 anomalous states of the j-3 multiplets[J]. Physical Review C, 2022, 106(6): 064319. doi: 10.1103/PhysRevC.106.064319
100. Luo, S., Xu, Y.-Y., Zhu, D.-X. et al. Improved Geiger–Nuttall law for α -decay half-lives of heavy and superheavy nuclei[J]. European Physical Journal A, 2022, 58(12): 244. doi: 10.1140/epja/s10050-022-00898-1
101. Basunia, M.S., Chakraborty, A. Nuclear Data Sheets for A=24[J]. Nuclear Data Sheets, 2022. doi: 10.1016/j.nds.2022.11.002
102. Wei, X.-B., Wei, H.-L., Wang, Y.-T. et al. Multiple-models predictions for drip line nuclides in projectile fragmentation of 40 , 48 Ca, 58 , 64 Ni, and 78 , 86 Kr at 140 MeV/u[J]. Nuclear Science and Techniques, 2022, 33(12): 155. doi: 10.1007/s41365-022-01137-4
103. Nabi, J.-U., Ullah, A., Khan, Z. Investigation of β-decay properties of neutron-rich Cerium isotopes[J]. Physica Scripta, 2022, 97(12): 125302. doi: 10.1088/1402-4896/ac9be7
104. Xing, F., Qi, H., Cui, J. et al. An improved Gamow-like formula for α-decay half-lives[J]. Nuclear Physics A, 2022. doi: 10.1016/j.nuclphysa.2022.122528
105. Crawford, H.L., Tripathi, V., Allmond, J.M. et al. Crossing N=28 Toward the Neutron Drip Line: First Measurement of Half-Lives at FRIB[J]. Physical Review Letters, 2022, 129(21): 212501. doi: 10.1103/PhysRevLett.129.212501
106. Huang, M.H., Gan, Z.G., Zhang, Z.Y. et al. α decay of the new isotope 204Ac[J]. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2022. doi: 10.1016/j.physletb.2022.137484
107. Choplin, A., Goriely, S., Siess, L. Synthesis of thorium and uranium in asymptotic giant branch stars[J]. Astronomy and Astrophysics, 2022. doi: 10.1051/0004-6361/202244928
108. Fang, J.Y., Chen, J., Niu, Z.M. Gross theory of β decay by considering the spin-orbit splitting from relativistic Hartree-Bogoliubov theory[J]. Physical Review C, 2022, 106(5): 054318. doi: 10.1103/PhysRevC.106.054318
109. Ismail, M., Ellithi, A.Y., Adel, A. et al. An improved unified formula for α -decay and cluster radioactivity of heavy and superheavy nuclei[J]. European Physical Journal A, 2022, 58(11): 225. doi: 10.1140/epja/s10050-022-00882-9
110. Wang, Q., Yan, X.-L., Chen, X.-C. et al. Spectral baseline estimation using penalized least squares with weights derived from the Bayesian method[J]. Nuclear Science and Techniques, 2022, 33(11): 148. doi: 10.1007/s41365-022-01132-9
111. Typel, S., Oertel, M., Klähn, T. et al. CompOSE reference manual: Version 3.01, CompStar Online Supernovæ Equations of State, “harmonising the concert of nuclear physics and astrophysics”, https://compose.obspm.fr[J]. European Physical Journal A, 2022, 58(11): 221. doi: 10.1140/epja/s10050-022-00847-y
112. Wang, M., Zhang, M., Zhou, X. et al. Bρ -defined isochronous mass spectrometry: An approach for high-precision mass measurements of short-lived nuclei[J]. Physical Review C, 2022, 106(5): L051301. doi: 10.1103/PhysRevC.106.L051301
113. Xu, Y.-Y., Zhu, D.-X., Zou, Y.-T. et al. Systematic study on α-decay half-lives of uranium isotopes with a screened electrostatic barrier* * Supported in part by the National Natural Science Foundation of China (12175100, 11975132), the Construct Program of the Key Discipline in Hunan Province, the Research Foundation of Education Bureau of Hunan Province, China (21B0402, 18A237), the Natural Science Foundation of Hunan Province, China (2018JJ2321), the Innovation Group of Nuclear and Particle Physics in USC, the Shandong Province Natural Science Foundation, China (ZR2019YQ01), the Hunan Provincial Innovation Foundation For Postgraduate (CX20210942) and the Opening Project of Cooperative Innovation Center for Nuclear Fuel Cycle Technology and Equipment, University of South China (2019KFZ10)[J]. Chinese Physics C, 2022, 46(11): 114103. doi: 10.1088/1674-1137/ac7fe8
114. Singh, B., Tuli, J.K., Browne, E. Nuclear Structure and Decay Data for A=231 Isobars[J]. Nuclear Data Sheets, 2022. doi: 10.1016/j.nds.2022.10.002
115. Singh, B., Chen, J. Nuclear Structure and Decay Data for A=149 Isobars[J]. Nuclear Data Sheets, 2022. doi: 10.1016/j.nds.2022.10.001
116. Zou, Y.-T., Pan, X., Li, X.-H. et al. Favored one proton radioactivity within a one-parameter model* * Supported by National Natural Science Foundation of China (Grant No.12175100 and No. 11705055), the construct program of the key discipline in Hunan province, the Research Foundation of Education Bureau of Hunan Province, China (Grant No. 18A237), the Innovation Group of Nuclear and Particle Physics in USC, the Shandong Province Natural Science Foundation, China (Grant No. ZR2019YQ01), and the Hunan Provincial Innovation Foundation For Postgraduate (Grant No. CX20210942).[J]. Communications in Theoretical Physics, 2022, 74(11): 115302. doi: 10.1088/1572-9494/ac7e2c
117. Shehzadi, R., Nabi, J.-U., Farooq, F. Half-life prediction of some neutron-rich exotic nuclei prior to peak A = 130[J]. Physica Scripta, 2022, 97(11): 115301. doi: 10.1088/1402-4896/ac95df
118. Walker, P.M.. Isomers as a bridge between nuclear and atomic physics[J]. Radiation Physics and Chemistry, 2022. doi: 10.1016/j.radphyschem.2022.110095
119. Huang, H., Zhang, W.Q., Andreyev, A.N. et al. First observation of the decay of the 13/2+ isomer in 183Hg and B(M2) systematics of neutron transitions across the nuclear chart[J]. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2022. doi: 10.1016/j.physletb.2022.137345
120. Vescovi, D., Reifarth, R., Cristallo, S. et al. Neutron-capture measurement candidates for the r-process in neutron star mergers[J]. Frontiers in Astronomy and Space Sciences, 2022. doi: 10.3389/fspas.2022.994980
121. Gamage, N.D., Sandler, R., Buchinger, F. et al. Precise Q -value measurements of Ag 112,113 and Cd 115 with the Canadian Penning trap for evaluation of potential ultralow Q -value β decays[J]. Physical Review C, 2022, 106(4): 045503. doi: 10.1103/PhysRevC.106.045503
122. Cheng, J.-H., Zhang, Z., Wu, X.-J. et al. Systematic study of proton radioactivity half-lives based on the relationship between Skyrme-Hartree-Fock and the macroscopic quantities of nuclear matter* * Supported in part by the National Natural Science Foundation of China (12175100), the construct program of the key discipline in Hunan province, the Research Foundation of Education Bureau of Hunan Province, China (18A237), the Natural Science Foundation of Hunan Province, China (2015JJ3103, 2015JJ2123), the Innovation Group of Nuclear and Particle Physics in USC[J]. Chinese Physics C, 2022, 46(10): 104104. doi: 10.1088/1674-1137/ac7a99
123. Davis, A.M.. Short-Lived Nuclides in the Early Solar System: Abundances, Origins, and Applications[J]. Annual Review of Nuclear and Particle Science, 2022. doi: 10.1146/annurev-nucl-010722-074615
124. Wahid, S.G., Tandel, S.K., Suman, S. et al. Emergence of an island of extreme nuclear isomerism at high excitation near 208Pb[J]. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2022. doi: 10.1016/j.physletb.2022.137262
125. Royer, G.. Calculation of two-proton radioactivity and application to Be 9, Li 6,7, He 3,6, and H 2,3 emissions[J]. Physical Review C, 2022, 106(3): 034605. doi: 10.1103/PhysRevC.106.034605
126. Moreno, O., Sarriguren, P., Algora, A. et al. Bulk and decay properties of neutron-deficient odd-mass Hg isotopes near A=185[J]. Physical Review C, 2022, 106(3): 034317. doi: 10.1103/PhysRevC.106.034317
127. Xu, Y.-Y., Zhu, D.-X., Chen, X. et al. A unified formula for α decay half-lives[J]. European Physical Journal A, 2022, 58(9): 163. doi: 10.1140/epja/s10050-022-00812-9
128. Cheng, S., Wu, W., Cao, L. et al. Isospin effects on α decay and cluster radioactivity[J]. European Physical Journal A, 2022, 58(9): 168. doi: 10.1140/epja/s10050-022-00825-4
129. Deng, J.-G., Zhang, H.-F. Probing the robustness of N=126 shell closure via the α decay systematics[J]. European Physical Journal A, 2022, 58(9): 165. doi: 10.1140/epja/s10050-022-00813-8
130. Peng, C., Feng, Z.-Q. Production of neutron-rich heavy nuclei around N= 162 in multinucleon transfer reactions[J]. European Physical Journal A, 2022, 58(9): 162. doi: 10.1140/epja/s10050-022-00819-2
131. Chen, J., Singh, B. Nuclear Structure and Decay Data for A=31 Isobars[J]. Nuclear Data Sheets, 2022. doi: 10.1016/j.nds.2022.08.002
132. Mumpower, M.R., Sprouse, T.M., Lovell, A.E. et al. Physically interpretable machine learning for nuclear masses[J]. Physical Review C, 2022, 106(2): L021301. doi: 10.1103/PhysRevC.106.L021301
133. Zhang, W.Q., Andreyev, A.N., Liu, Z. et al. Identification of excited states in Bi 188 and Po 188[J]. Physical Review C, 2022, 106(2): 024317. doi: 10.1103/PhysRevC.106.024317
134. Nesterenko, D.A., Blaum, K., Delahaye, P. et al. Direct determination of the excitation energy of the quasistable isomer Ta 180m[J]. Physical Review C, 2022, 106(2): 024310. doi: 10.1103/PhysRevC.106.024310
135. Medeiros, E.L., Teruya, N., Duarte, S.B. et al. Nonlocality effect in α decay of heavy and superheavy nuclei[J]. Physical Review C, 2022, 106(2): 024608. doi: 10.1103/PhysRevC.106.024608
136. Wang, Z., Ren, Z. Favored α -decay half-lives of odd- A and odd-odd nuclei using an improved density-dependent cluster model with anisotropic surface diffuseness[J]. Physical Review C, 2022, 106(2): 024311. doi: 10.1103/PhysRevC.106.024311
137. Suman, S., Tandel, S.K., Wahid, S.G. et al. Successive neutron alignments in the yrast, negative-parity band of oblate-deformed Tl 199[J]. Physical Review C, 2022, 106(2): 024316. doi: 10.1103/PhysRevC.106.024316
138. Borzov, I.N., Tolokonnikov, S.V. Self-Consistent Study of the Ground State and β-Decay Properties of Oxygen and Fluorine Isotopes[J]. Physics of Atomic Nuclei, 2022, 85(4): 351-359. doi: 10.1134/S1063778822040068
139. Akrawy, D.T., Budaca, A.I., Saxena, G. et al. Generalization of the screened universal α-decay law by asymmetry and angular momentum[J]. European Physical Journal A, 2022, 58(8): 145. doi: 10.1140/epja/s10050-022-00789-5
140. Quyen, N.T.T., Chae, K.Y., Uyen, N.K. et al. Beta-decay half-lives of the isotopes close to the neutron drip line and astrophysical implications[J]. Physica Scripta, 2022, 97(8): 085301. doi: 10.1088/1402-4896/ac7d16
141. Belli, P., Bernabei, R., Cappella, F. et al. Search for naturally occurring seaborgium with radiopure 116CdWO4crystal scintillators[J]. Physica Scripta, 2022, 97(8): 085302. doi: 10.1088/1402-4896/ac7a6d
142. Kelderman, C.A.A., Davey, P.R.W.J., Ma, M.T. et al. Hexadentate technetium-99m bis(thiosemicarbazonato) complexes: synthesis, characterisation and biodistribution[J]. Dalton Transactions, 2022, 51(37): 14064-14078. doi: 10.1039/d2dt01264b
143. Pan, C., Cheoun, M.-K., Choi, Y.-B. et al. Deformed relativistic Hartree-Bogoliubov theory in continuum with a point-coupling functional. II. Examples of odd Nd isotopes[J]. Physical Review C, 2022, 106(1): 014316. doi: 10.1103/PhysRevC.106.014316
144. Batchelder, J.C., Hurst, A.M., Basunia, M.S. Nuclear Data Sheets for A=186[J]. Nuclear Data Sheets, 2022. doi: 10.1016/j.nds.2022.06.001
145. Ismail, M., Ellithi, A.Y., Adel, A. et al. Improved empirical formulas for α-decay half-lives of heavy and superheavy nuclei[J]. Physica Scripta, 2022, 97(7): 075303. doi: 10.1088/1402-4896/ac758c
146. Ma, C.-W., Wei, X.-B., Chen, X.-X. et al. Precise machine learning models for fragment production in projectile fragmentation reactions using Bayesian neural networks[J]. Chinese Physics C, 2022, 46(7): 074104. doi: 10.1088/1674-1137/ac5efb
147. Zhang, W.Q., Andreyev, A.N., Liu, Z. et al. First observation of a shape isomer and a low-lying strongly-coupled prolate band in neutron-deficient semi-magic 187Pb[J]. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2022. doi: 10.1016/j.physletb.2022.137129
148. Chen, M.-H., Hu, R.-C., Liang, E.-W. Radioactively Powered Gamma-Ray Transient Associated with a Kilonova from Neutron Star Merger[J]. Astrophysical Journal Letters, 2022, 932(1): L7. doi: 10.3847/2041-8213/ac7470
149. Li, H.-F., Xu, X., Wang, M. et al. On the masses of A = 54 isospin septet and the isobaric multiplet mass equation[J]. Chinese Physics C, 2022, 46(6): 064001. doi: 10.1088/1674-1137/ac5600
150. Nichols, A.L.. Status of the decay data for medical radionuclides: Existing and potential diagnostic γemitters, diagnostic β+emitters and therapeutic radioisotopes[J]. Radiochimica Acta, 2022, 110(6-9): 609-644. doi: 10.1515/ract-2022-0004
151. Pan, X., Zou, Y.-T., He, B. et al. Systematic study of two-proton radioactivity half-lives using two-potential approach with different Skyrme interactions[J]. International Journal of Modern Physics E, 2022, 31(5): 2250051. doi: 10.1142/S0218301322500513
152. Gui, H.-F., Liu, H.-M., Wu, X.-J. et al. Systematic study of α decay half-lives for even-even nuclei within a deformed two-potential approach[J]. Communications in Theoretical Physics, 2022, 74(5): 055301. doi: 10.1088/1572-9494/ac6576
153. Prohaska, T., Irrgeher, J., Benefield, J. et al. Standard atomic weights of the elements 2021 (IUPAC Technical Report)[J]. Pure and Applied Chemistry, 2022, 94(5): 573-600. doi: 10.1515/pac-2019-0603
154. Fan, J., Xu, C. Exploring the half-lives of extremely long-lived α emitters[J]. Chinese Physics C, 2022, 46(5): 054105. doi: 10.1088/1674-1137/ac500d
155. Choplin, A., Goriely, S., Hirschi, R. et al. The p-process in exploding rotating massive stars[J]. Astronomy and Astrophysics, 2022. doi: 10.1051/0004-6361/202243331
156. Azeez, O.K., Yahya, W.A., Saeed, A.A. Predictions of the alpha-decay half-lives of even-even superheavy nuclei using modified Gamow-like model[J]. Physica Scripta, 2022, 97(5): 055302. doi: 10.1088/1402-4896/ac619d
157. Royer, G., Ferrier, Q., Pineau, M. Alpha and cluster decays of superheavy elements and 2p radioactivity of medium nuclei[J]. Nuclear Physics A, 2022. doi: 10.1016/j.nuclphysa.2022.122427
158. Duy, N.N., Uyen, N.K., Chae, K.Y. MRTOF-S: a toolkit for pre-estimating precise mass measurements using MRTOF spectrometer[J]. Journal of the Korean Physical Society, 2022, 80(9): 887-897. doi: 10.1007/s40042-022-00427-9
159. Vladimirova, E.V., Simonov, M.V., Negrebetskiy, V.V. et al. New Mass Evaluation and Its Implication for the Neutron-Rich Nucleosynthesis Product Yield[J]. Bulletin of the Russian Academy of Sciences: Physics, 2022, 86(4): 473-478. doi: 10.3103/S1062873822040268
160. Lam, Y.H., Liu, Z.X., Heger, A. et al. Impact of the New 65As(p, γ)66Se Reaction Rate on the Two-proton Sequential Capture of 64Ge, Weak GeAs Cycles, and Type I X-Ray Bursts Such as the Clocked Burster GS 1826-24[J]. Astrophysical Journal, 2022, 929(1): 72. doi: 10.3847/1538-4357/ac4d8b
161. Gillespie, S.A., Brown, K.W., Charity, R.J. et al. Proton decay spectroscopy of S 28 and Cl 30[J]. Physical Review C, 2022, 105(4): 044321. doi: 10.1103/PhysRevC.105.044321
162. Yagi, A., Odahara, A., Nishibata, H. et al. Various nuclear structures in Xe 140 studied by β decay of ground and isomeric states in i 140[J]. Physical Review C, 2022, 105(4): 044325. doi: 10.1103/PhysRevC.105.044325
163. Porter, W.S., Ashrafkhani, B., Bergmann, J. et al. Mapping the N=40 island of inversion: Precision mass measurements of neutron-rich Fe isotopes[J]. Physical Review C, 2022, 105(4): L041301. doi: 10.1103/PhysRevC.105.L041301
164. Geue, N., Bandemer, J., Rossa, J. et al. asks of the school competition Chemie-die-stimmt!: From nuclides and decay chains | [Von Nukliden und Zerfallsreihen: Aufgaben des Schülerwettbewerbs Chemie-die-stimmt!][J]. Chemie in Unserer Zeit, 2022, 56(2): 138-140. doi: 10.1002/ciuz.202200005
165. Sharma, R., Jain, A., Sharma, P.K. et al. A comprehensive study of decay modes associated with Pb isotopes[J]. Physica Scripta, 2022, 97(4): 045307. doi: 10.1088/1402-4896/ac607c
166. Basunia, M.S.. Nuclear Data Sheets for A=213[J]. Nuclear Data Sheets, 2022. doi: 10.1016/j.nds.2022.03.002
167. Nica, N., Singh, B. Nuclear Data Sheets for A=147[J]. Nuclear Data Sheets, 2022. doi: 10.1016/j.nds.2022.03.001
168. Mukai, M., Hirayama, Y., Watanabe, Y.X. et al. Ground-state β-decay spectroscopy of Ta 187[J]. Physical Review C, 2022, 105(3): 034331. doi: 10.1103/PhysRevC.105.034331
169. Tezekbayeva, M.S., Yeremin, A.V., Svirikhin, A.I. et al. Study of the production and decay properties of neutron-deficient nobelium isotopes[J]. European Physical Journal A, 2022, 58(3): 52. doi: 10.1140/epja/s10050-022-00707-9
170. Zerkin, V.V., Pritychenko, B., Totans, J. et al. EXFOR-NSR PDF database: A system for nuclear knowledge preservation and data curation[J]. Journal of Instrumentation, 2022, 17(3): P03012. doi: 10.1088/1748-0221/17/03/P03012
171. Parr, E., Smith, J.F., Greenlees, P.T. et al. Single-particle states and parity doublets in odd- Z Ac 221 and Pa 225 from α -decay spectroscopy[J]. Physical Review C, 2022, 105(3): 034303. doi: 10.1103/PhysRevC.105.034303
172. Yahya, W.A., Ibrahim, T.T. Cluster decay half-lives using relativistic density dependent double folding model[J]. European Physical Journal A, 2022, 58(3): 48. doi: 10.1140/epja/s10050-022-00701-1
173. Zhang, K., Cheoun, M.-K., Choi, Y.-B. et al. Nuclear mass table in deformed relativistic Hartree–Bogoliubov theory in continuum, I: Even–even nuclei[J]. Atomic Data and Nuclear Data Tables, 2022. doi: 10.1016/j.adt.2022.101488
174. Wang, Z., Bai, D., Ren, Z. Improved density-dependent cluster model in a -decay calculations within anisotropic deformation-dependent surface diffuseness[J]. Physical Review C, 2022, 105(2): 024327. doi: 10.1103/PhysRevC.105.024327
175. Cheng, J.-H., Li, Y., Yu, T.-P. Systematic study of laser-assisted proton radioactivity from deformed nuclei[J]. Physical Review C, 2022, 105(2): 024312. doi: 10.1103/PhysRevC.105.024312
176. Meisel, Z., Hamaker, A., Bollen, G. et al. Improved nuclear physics near A=61 refines urca neutrino luminosities in accreted neutron star crusts[J]. Physical Review C, 2022, 105(2): 025804. doi: 10.1103/PhysRevC.105.025804
177. Iimura, H., Katakura, J., Ohya, S. Nuclear Data Sheets for A=126[J]. Nuclear Data Sheets, 2022. doi: 10.1016/j.nds.2022.02.001
178. Xu, Y.-Y., Liu, H.-M., Zhu, D.-X. et al. An improved formula for the favored α decay half-lives[J]. European Physical Journal A, 2022, 58(2): 16. doi: 10.1140/epja/s10050-022-00666-1
179. Wang, X.-Q., Sun, X.-X., Zhou, S.-G. Microscopic study of higher-order deformation effects on the ground states of superheavy nuclei around 270Hs[J]. Chinese Physics C, 2022, 46(2): 024107. doi: 10.1088/1674-1137/ac3904
180. Uyen, N.K., Chae, K.Y., Duy, N.N. et al. Beta-decay half-lives of the extremely neutron-rich nuclei in the closed-shell N = 50, 82, 126 groups[J]. Journal of Physics G: Nuclear and Particle Physics, 2022, 49(2): 025201. doi: 10.1088/1361-6471/ac3cfa
181. Tian, R., Li, H., Hu, Y. et al. Probe of proton drip line nuclei near Z = 50 indicated by nuclear shell model[J]. Results in Physics, 2022. doi: 10.1016/j.rinp.2022.105173
182. Chien, L.H., Phuc, N.T.T. On the Bohr-Sommerfeld quantization condition and assault frequency in a semiclassical model for α decay[J]. Nuclear Physics A, 2022. doi: 10.1016/j.nuclphysa.2021.122373
183. Yahya, W.A., Olusola, I.D., Saeed, A.A. et al. Half-lives of α-decay from nuclei with Z = 92 − 118 using the double folding model with relativistic NN interactions[J]. Nuclear Physics A, 2022. doi: 10.1016/j.nuclphysa.2021.122360
184. Shimada, A.. Recent Progress of 135Cs Concentration and135Cs/137Cs Isotopic Ratio Measurement[J]. Bunseki Kagaku, 2022, 71(12): 625-633. doi: 10.2116/bunsekikagaku.71.625
185. Cai, B., Yuan, C. Theoretical description of the decay width of neutron emission in light nuclei | [轻质量原子核中子发射的衰变宽度理论描述][J]. Kexue Tongbao/Chinese Science Bulletin, 2022, 67(23): 2782-2789. doi: 10.1360/TB-2022-0151
186. Kankainen, A., Goriely, S. Nuclear Data and Experiments for Astrophysics[J]. Lecture Notes in Physics, 2022. doi: 10.1007/978-3-031-10751-1_4
187. Neve, F.. Chemistry of superheavy transition metals[J]. Journal of Coordination Chemistry, 2022, 75(17-18): 2287-2307. doi: 10.1080/00958972.2022.2084394
188. Li, P., Bai, J., Niu, Z. et al. β-decay half-lives studied using neural network method | [神经网络方法对β衰变寿命的研究][J]. Scientia Sinica: Physica, Mechanica et Astronomica, 2022, 52(5): 252006. doi: 10.1360/SSPMA-2021-0299
189. Terranova, M.L., Tavares, O.A.P. The periodic table of the elements: the search for transactinides and beyond[J]. Rendiconti Lincei, 2022. doi: 10.1007/s12210-022-01057-w
190. Saeed, A.A., Yahya, W.A., Azeez, O.K. PREDICTIONS OF α-DECAY HALF-LIVES FOR NEUTRON-DEFICIENT NUCLEI WITH THE AID OF ARTIFICIAL NEURAL NETWORK[J]. Acta Physica Polonica B, 2022, 53(1): A4. doi: 10.5506/APhysPolB.53.1-A4
191. Sarriguren, P.. Competition between weak and α -decay modes in superheavy nuclei[J]. Physical Review C, 2022, 105(1): 014312. doi: 10.1103/PhysRevC.105.014312
192. Chen, J.. Nuclear Data Sheets for A=48[J]. Nuclear Data Sheets, 2022. doi: 10.1016/j.nds.2021.12.001
193. Yahya, W.A., Kimene Kaya, B.D.C. The α-decay half-lives of heavy nuclei via the double folding model with the use of relativistic NN interactions[J]. International Journal of Modern Physics E, 2022, 31(1): 2250002. doi: 10.1142/S0218301322500021
194. Budaca, R., Budaca, A.I. Deformation dependence of the screened decay law for proton emission[J]. Nuclear Physics A, 2022. doi: 10.1016/j.nuclphysa.2021.122355
195. Wang, X., Clark, A.M., Ellis, J. et al. r-Process Radioisotopes from Near-Earth Supernovae and Kilonovae[J]. Astrophysical Journal, 2021, 923(2): 219. doi: 10.3847/1538-4357/ac2d90
196. Watanabe, H., Yuan, C.X., Lorusso, G. et al. Impact of shell evolution on Gamow-Teller β decay from a high-spin long-lived isomer in 127Ag[J]. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2021. doi: 10.1016/j.physletb.2021.136766
197. Hassanzad, M., Ghodsi, O.N. Theoretical study on the favored alpha-decay half-lives of deformed nuclei[J]. Chinese Physics C, 2021, 45(12): 124106. doi: 10.1088/1674-1137/ac28f3
198. Paul, S.F., Bergmann, J., Cardona, J.D. et al. Mass measurements of Ga 60-63 reduce x-ray burst model uncertainties and extend the evaluated T=1 isobaric multiplet mass equation[J]. Physical Review C, 2021, 104(6): 065803. doi: 10.1103/PhysRevC.104.065803
199. Santhosh, K.P.. Theoretical studies on two-proton radioactivity[J]. Physical Review C, 2021, 104(6): 064613. doi: 10.1103/PhysRevC.104.064613
200. Wan, N., Fan, J. Systematical calculations on α -cluster preformation factors and decay half-lives of light nuclei near the recently observed α emitters Xe 108 and Te 104[J]. Physical Review C, 2021, 104(6): 064320. doi: 10.1103/PhysRevC.104.064320
201. Li, H., Ren, Z., Dong, C. et al. Closed-shell effect in two-neutrino double- β decay for fp shell nuclei[J]. Physical Review C, 2021, 104(6): 064307. doi: 10.1103/PhysRevC.104.064307
202. Singh, B., Chen, J. Nuclear Data Sheets for A=64[J]. Nuclear Data Sheets, 2021. doi: 10.1016/j.nds.2021.11.002
203. Bao, M., Wei, Q. Nuclear structure evolution reflected from local relations[J]. Symmetry, 2021, 13(12): 2253. doi: 10.3390/sym13122253
204. Saxena, G., Kumawat, M., Sharma, R. et al. Collapse of N = 28 magicity in exotic 40Mg - Probe of deformed halo and 2n-radioactivity at Mg neutron drip-line[J]. Journal of Physics G: Nuclear and Particle Physics, 2021, 48(12): 125102. doi: 10.1088/1361-6471/ac288b
205. Xing, F., Cui, J., Wang, Y. et al. Two-proton radioactivity of ground and excited states within a unified fission model[J]. Chinese Physics C, 2021, 45(12): 124105. doi: 10.1088/1674-1137/ac2425
206. Sharma, P.K., Jain, A., Saxena, G. New modified empirical formulae for favoured and unfavoured α-decay[J]. Nuclear Physics A, 2021. doi: 10.1016/j.nuclphysa.2021.122318
207. Doherty, D.T., Andreyev, A.N., Seweryniak, D. et al. Solving the Puzzles of the Decay of the Heaviest Known Proton-Emitting Nucleus Bi 185[J]. Physical Review Letters, 2021, 127(20): 202501. doi: 10.1103/PhysRevLett.127.202501
208. Andel, B., Van Duppen, P., Andreyev, A.N. et al. New β -decaying state in Bi 214[J]. Physical Review C, 2021, 104(5): A76. doi: 10.1103/PhysRevC.104.054301
209. Liu, M., Yuan, C. Cross-shell excitation in F and Ne isotopes around N = 20[J]. Symmetry, 2021, 13(11): 2167. doi: 10.3390/sym13112167
210. Kondev, F.G.. Nuclear Data Sheets for A=203[J]. Nuclear Data Sheets, 2021. doi: 10.1016/j.nds.2021.09.002
211. Chen, J., Singh, B. Nuclear Data Sheets for A=194[J]. Nuclear Data Sheets, 2021. doi: 10.1016/j.nds.2021.09.001
212. Ma, C.-W., Wei, H.-L., Liu, X.-Q. et al. Nuclear fragments in projectile fragmentation reactions[J]. Progress in Particle and Nuclear Physics, 2021. doi: 10.1016/j.ppnp.2021.103911
213. Yahya, W.A., Falaye, B.J. Alpha decay study of Thorium isotopes using double folding model with NN interactions derived from relativistic mean field theory[J]. Nuclear Physics A, 2021. doi: 10.1016/j.nuclphysa.2021.122311
214. Çakmak, Ş., Çakmak, N. Beta decay logft values for zinc isotopes by using pn-QRPA[J]. Nuclear Physics A, 2021. doi: 10.1016/j.nuclphysa.2021.122287
215. Naik, H., Dange, S.P., Singh, R.J. et al. Post-neutron mass yield distribution in the thermal neutron induced fission of 238Pu[J]. Annals of Nuclear Energy, 2021. doi: 10.1016/j.anucene.2021.108493
216. Piersa-Siłkowska, M., Korgul, A., Benito, J. et al. First -decay spectroscopy of and new -decay branches of[J]. Physical Review C, 2021, 104(4): 044328. doi: 10.1103/PhysRevC.104.044328
217. Duy Ly, N., Ngoc Duy, N., Kim Uyen, N. et al. Examination of n - T 9conditions required by N = 50, 82, 126 waiting points in r-process[J]. Communications in Theoretical Physics, 2021, 73(10): 105301. doi: 10.1088/1572-9494/ac1dad
218. Beck, S., Kootte, B., Dedes, I. et al. Mass Measurements of Neutron-Deficient Yb Isotopes and Nuclear Structure at the Extreme Proton-Rich Side of the N=82 Shell[J]. Physical Review Letters, 2021, 127(11): 112501. doi: 10.1103/PhysRevLett.127.112501
219. Baldik, R.. Investigating the excitation functions of the neutron-induced reactions leading to the radioactive products on natural titanium isotopes[J]. Fusion Engineering and Design, 2021. doi: 10.1016/j.fusengdes.2021.112725
220. Zhang, K., He, X., Meng, J. et al. Predictive power for superheavy nuclear mass and possible stability beyond the neutron drip line in deformed relativistic Hartree-Bogoliubov theory in continuum[J]. Physical Review C, 2021, 104(2): L021301. doi: 10.1103/PhysRevC.104.L021301

Figures(7)

Get Citation
F.G. Kondev, M. Wang, W.J. Huang, S. Naimi and G. Audi. The NUBASE2020 evaluation of nuclear physics properties[J]. Chinese Physics C, 2021, 45(3): 030001. doi: 10.1088/1674-1137/abddae
F.G. Kondev, M. Wang, W.J. Huang, S. Naimi and G. Audi. The NUBASE2020 evaluation of nuclear physics properties[J]. Chinese Physics C, 2021, 45(3): 030001.  doi: 10.1088/1674-1137/abddae shu
Milestone
Received: 2021-01-19
Article Metric
Article has an altmetric score of 37
Article has an altmetric score of 37

Article Views(3878)
PDF Downloads(353)
Cited by(450)
Policy on re-use
To reuse of Open Access content published by CPC, for content published under the terms of the Creative Commons Attribution 3.0 license (“CC CY”), the users don’t need to request permission to copy, distribute and display the final published version of the article and to create derivative works, subject to appropriate attribution.
通讯作者: 陈斌, bchen63@163.com
  • 1. 

    沈阳化工大学材料科学与工程学院 沈阳 110142

  1. 本站搜索
  2. 百度学术搜索
  3. 万方数据库搜索
  4. CNKI搜索

Email This Article

Title:
Email:

The NUBASE2020 evaluation of nuclear physics properties

    Corresponding author: M. Wang, wangm@impcas.ac.cn (M. Wang), corresponding author
  • 1. Physics Division, Argonne National Laboratory, Lemont, IL 60439, USA
  • 2. Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
  • 3. School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
  • 4. Advanced Energy Science and Technology Guangdong Laboratory, Huizhou 516003, China
  • 5. Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
  • 6. Université Paris-Saclay, CNRS/IN2P3, IJCLab, 91405 Orsay, France
  • 7. RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
  • Received Date: 2021-01-19
  • Available Online: 2021-03-15

Abstract: 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.

    HTML

    1.   Introduction

    • NUBASE2020 is an evaluated nuclear data library that contains the recommended values of the main nuclear physics properties: masses, excitation energies (for excited isomers), half-lives, spins and parities and decay modes, and their intensities, for all known nuclei in their ground and excited, isomeric (T 1/2 ≥ 100 ns) states. It also includes information for yet unobserved nuclides that is based on systematic trends of nuclear properties in neighboring nuclei. The present publication includes updated results for these properties, which were reported in previous versions of this library [1–4]. The recommended data are presented in Table I.

      The information included in NUBASE2020 represents the fundamental building blocks of the modern nuclear physics, and specifically of the nuclear structure and nuclear astrophysics research. One of the main applications of NUBASE2020 is the “Atomic Mass Evaluation” (AME2020 - the second and third articles included in this issue) where it is imperative to have an unambiguous identification of all states involved in a particular decay, reaction or mass-spectrometry measurement. This is the main reason for coupling the two evaluations together in the present issue. Furthermore, with the advances of modern mass-spectrometry techniques and the availability of intense stable and rare-isotope beams, a large number of short-lived nuclei can be produced in a single experiment and their masses can be measured with a high precision. Thus, NUBASE2020 can be a trusted source of information in future mass measurements, where an unambiguous identification of specific nuclides in complex mass-spectrometry data would be required.

      NUBASE2020 also serves nuclear structure research, astrophysics network calculations, and theoretical studies of nuclear properties, where complete, up-to-date and reliable data for all known nuclei are needed. It can be particularly useful in present and future studies of nuclei and their properties at the major nuclear physics facilities around the world, such as FAIR, ISOLDE and SPIRAL2 (Europe), ATLAS and FRIB (USA), HIAF (China), RIBF at RIKEN (Japan), ISAC and ARIEL (Canada), and elsewhere.

      Furthermore, the evaluated data included in NUBASE2020 are a valuable source of information for specialists in a number of applied nuclear fields, such as safeguards, nuclear forensics, reactor engineering, waste management, material analysis, medical diagnostics and radiotherapy, and elsewhere, where one needs to access reliable nuclear physics information for any nuclide.

      The recommended data included in NUBASE2020 fulfill several user-demanded requirements, namely that they are: a) complete − include all measured quantities and their uncertainties, b) up-to-date − include results from all recent publications, c) credible and reliable − identify and resolve contradictory results that exist in the scientific literature, as well as in other nuclear physics databases, d) properly referenced − provide comprehensive bibliographical information for all included properties.

      In general, NUBASE2020 was updated via three different routes: a) directly from the literature by compiling and evaluating data that were published in primary (nuclear physics journals) and secondary (abstracts, conference proceedings, private communications, theses, arXiv publications and laboratory reports) references; b) by consulting, and when merited by adopting, recommendations made in topical evaluations that include nuclear properties covered by NUBASE (see the text for details); c) by consulting, and when merited by adopting, recommended values from the “Evaluated Nuclear Structure Data File” (ENSDF) database [5].

      It is important to note that data presented in ENSDF and in other topical evaluations were carefully examined, and only results that were found to be valid and up-to-date were considered. In general, the content of ENSDF is very large, since it encompasses the complex nuclear structure and decay properties for all nuclei and all excited nuclear states. Maintenance of this library requires an enormous effort and it is not surprising that occasionally some older data are missing or misrepresented, and that some recent data are not included. When such cases were identified, the data were re-evaluated and the corresponding conclusions were added as comments in Table I.

      The content of NUBASE2020, together with the adopted policies that were used during the development of this nuclear physics data library, is described below. All experimental data available to the authors by October 30, 2020 were considered.

    2.   Content of NUBASE2020

    • The NUBASE2020 evaluation contains recommended properties for the ground state of 3340 nuclides and for 1938 excited isomeric (T 1/2 ≥ 100 ns) states, derived from all available experimental data. It also includes information for yet unobserved nuclei (218 in their ground state and 45 excited isomers) whose properties were estimated by following the systematic trends in neighboring nuclei (TNN, see section 3.1).

      For each nuclide and for each state (ground or isomeric), the following properties were compiled and, when necessary, evaluated: mass excess, excitation energy of the excited isomeric state, half-life, spin and parity, decay modes and their intensities, isotopic abundance (for stable nuclides), year of discovery and the corresponding bibliographical information for all experimental values of the above items.

      • 2.1.   Mass excess

    • In general, the knowledge of atomic masses can provide valuable information on the lifetimes of nuclear states and their decay modes, and in particular on the β -delayed particle decay probabilities for nuclei far from the line of stability.

      The mass-excess values and their uncertainties that are presented in Table I were adopted from the latest edition of the Atomic Mass Evaluation, AME2020, as described in the second and third articles of the present issue. Figure 1 displays the uncertainties of the mass-excess values as a function of N and Z.

      Figure 1.  Nuclear chart displaying the mass-excess uncertainties for all nuclei in their ground state.

      • 2.2.   Isomers

    • Nuclear isomers are excited, intrinsic (single-particle in nature) states with lifetimes ranging from nanoseconds (or even shorter) to years. There are several recent compilations and review articles, where the physics of nuclear isomers was discussed in detail and the reader is referred to Refs. [6, 7] and references therein.

      Following the NUBASE2003 publication [2], the present evaluation includes isomeric states with half-lives longer than 100 ns. Although this limit is somewhat arbitrary, the main reason for this choice was to include all short-lived isomers that can be directly produced at the present and future accelerator beam facilities and that can survive the time-of-flight path of the employed recoil mass separator, and as a consequence, their decay properties and/or masses can be directly measured.

      Figure 2 shows a compilation of all such known isomers as a function of N and Z.

      Figure 2.  Nuclear chart displaying isomeric states with T 1/2 ≥ 100 ns. For a given isotope where multiple isomers exist, only the longest-lived state is plotted.

      Isomers are listed in Table I in the order of increasing excitation energy and they are identified by the letters ‘m’, ‘n’, ‘p’, ‘q’, or ‘r’ which are appended to the nuclide name, e.g. 90 Nb for the ground state, 90 Nb m for the first excited isomer, 90 Nb n , 90 Nb p , 90 Nb q , and 90 Nb r for the second, third, fourth and fifth ones, respectively. In four cases, namely 98 Y, 174 Lu, 179 Ta and 214 Ra, a sixth isomer is presented and they were labeled with the letter ‘x’ (see the Explanation of Table I for details).

      The excitation energy of an isomeric states is determined by different experimental methods, which are generally attributed to the category of either internal or external relations. A typical internal relation involves the γ -ray energy, or the energies of a cascade of γ rays, associated with the isomer decay. The most-accurate values for the excitation energies of isomers that are deduced by this approach can be determined by a least-squares fit to the energies of all γ rays observed along the decay path of a particular isomer. In cases where internal relations cannot be established, connections to other nuclides (external relations) can be used to deduce the mass difference (excitation energy) between the ground state and isomers, and the excitation energies are taken from AME2020.

      The method used to establish the external relation for a particular isomer (the origin) is indicated by a two-letter code in Table I, next to the isomer excitation energy (see the Explanation of Table I for details). For internal relations, the origin field is left blank and the numerical values are taken either from ENSDF or from literature updates, where a least-squares fit to the measured γ -ray energies was performed, whenever possible.

      There are also cases where the energy difference between the isomer and the ground state can be obtained by both the internal and one, or more, external relations with comparable accuracies. In such cases, the excitation energy of the isomer is taken from AME2020. For example, the mass of 178 Lu m is determined in AME2020 at 66% from E x (IT) = 120(3) keV [1993Bu02] and at 34% from 176 Lu(t,p) 178 Lu m = 4482(5) keV [1981Gi01], resulting in an adjusted excitation energy of 123.8(2.6) keV for the isomer.

      In contrast to ENSDF, where the isomer excitation energies may not be quantified and are often given as floating levels with ‘+X’, ‘+Y’, etc., estimated values are always provided in NUBASE2020, based on theoretical considerations or TNN. In such cases, the reported excitation energies are considered as a non-experimental quantity and the values are flagged with the symbol ‘#’.

      When the existence of an isomer is uncertain and it is still under discussion, it is flagged with ‘EU’ (“Existence Uncertain”) in the origin field. A comment is usually added to indicate why the existence of this state is questioned or where this issue is discussed in more detail. Eleven isomers, namely 138 Pm m , 142 Nd m , 144 Cs n , 152 Pm n , 156 Tm m , 162 Lu n , 174 W m , 174 W n , 185 Bi n , 190 Tl n , and 273 Ds m are treated in this way in the present evaluation. Nevertheless, the mass excess and excitation energy values are given for all of them, except for 138 Pm m , 142 Nd m , 144 Cs n , 152 Pm n , 174 W m , 174 W n , and 190 Tl n , where the existence is strongly doubted.

      When an isomer was initially reported as “discovered”, but later this was proven to be an error, such a case is flagged with ‘RN’ (“Reported Non-existent”) in the origin field. Nine isomers, namely 76 Cu m , 84 Ga m , 84 As m , 85 Nb n , 86 Nb n , 117 La m , 181 Pb m , 196 Pb m , and 197 Bi n are treated in this way and no mass excess or excitation energy values are given. Similarly to the ‘EU’ cases, a “non-exist” label is also added. The use of the two flags, ‘EU’ and ‘RN’, was extended to cases where the discovery of a nuclide is questioned (e.g. 260 Fm or 289 Lv or 293 Og). However, an estimate for the ground state mass, derived from Trends from the Mass Surface (TMS), is always given in AME2020 and NUBASE2020.

      Sometimes, upper and lower limits are known for the excitation energy of the isomeric state. Such cases are treated with uniform probability distribution, as explained in section 3.2. For example, there is solid experimental evidence [1974De47] that the excitation energy of the 162 Tm m isomer is between the 66.9 keV and 192.0 keV levels and this information is presented (after rounding) in Table I as Ex=130(40) keV.

      When it is not clear which state is the ground state and which one is the isomer, the flag ‘ ∗ ’ is added in Table I. Similarly, when the uncertainty of the isomer excitation energy, Δ Ex , is relatively large compared to Ex , e.g. Δ Ex > Ex/2 , the assignment of the level as a ground or isomeric state is also considered to be uncertain and it is flagged with the symbol ‘ ∗ ’, as well.

      Based on new experimental mass information, the ordering of several ground and excited isomeric states was reversed in the present work, when compared to the recommendations in ENSDF, and such cases are flagged with the symbol ‘&’ in Table I. In a few other instances, evidence was found for a state that is located below the adopted in ENSDF ground state and such results were also flagged with the symbol ‘&’ in Table I. It is worth noting that because of the coupling between NUBASE2020 and AME2020 all changes in the ordering of nuclear levels are firmly established and synchronized.

      • 2.2.1.   Isobaric analog states

    • NUBASE2020 contains information for 205 Isobaric Analog States (IAS), which are labeled in Table I with the isospin multiplet value, T. Their excitation energies were determined via either the “internal” or “external” relation. The IAS nuclides are generally marked with the i or j superscripts, except for eight excited isomers, 16 N m , 26 Al m , 34 Cl m , 38 K m , 46 V m , 50 Mn m , 54 Co m , and 70 Br m . The isospin value is not given for most nuclei in their ground state, since they have T = ∣Tz∣ = 12 ∣(N−Z)∣ . However, it is included for the ground state of the N=Z , odd-odd 34 Cl, 42 Sc, 46 V, 50 Mn, 54 Co, 62 Ga, 66 As, 70 Br, and 74 Rb ( T=1 ) and 30 P, 38 K, and 58 Cu ( T=0 ) nuclides.

      Detailed experimental information about IAS was recently compiled in Refs. [8, 9].

      • 2.3.   Half-life

    • The lifetime is a fundamental property of a nuclear level. It is related to the total decay width, Γ , a linear sum of all partial decay widths ( γ ray, conversion electrons, α decay, β decay, fission, etc.), through the uncertainty relationship:

      Γ=ℏτ

      		(1)

      where τ = T 1/2 /ln(2) is the level mean life and T 1/2 is the half-life.

      Figures 3 displays the ground-state half-life as a function of N and Z for all nuclei included in Table I.

      Figure 3.  Nuclear chart displaying the ground-state half-lives for all nuclei.

      Some light nuclei (A < 30) that are located beyond the particle drip-lines are known to exist for a very short time before disintegrating by particle emissions. In such cases only the total level width can be measured and the half-life is deduced by means of equation 1 (in convenient units):

      T1/2[s]≃4.562×10−22/Γ[MeV]

      		(2)

      where Γ is the total width in the center of mass frame. The heaviest nuclide whose half-life is determined by this approach is 29 Cl.

      The following units are used in NUBASE2020 for a convenient display of half-lives: seconds (s) and its sub-units, minutes (m), hours (h), days (d) and years (y), and its sub-units (see Explanation of Table I for details). While several definitions can be used to convert values between years and days or seconds, such as Julian year, Gregorian year, Sidereal year, Tropical year and others, the conversion via Tropical year is adopted in NUBASE2020:

      1y=365.2422d=31556926s

      When more than one value is known for the half-life of a particular level, a statistical analysis was performed in accordance with the policies outlined in section 3.2. Experimental half-lives are sometimes given in the literature with most probable lower and upper limits. Such cases are treated with uniform probability distribution, as explained in section 3.2. For example, the half-life of 97 In m is given as 1.2 μ s ≤ T 1/2 ≤ 230 μ s in Ref. [2018Pa20] and the recommended value in NUBASE2020 is T 1/2 = 120(70) μ s. Half-lives with asymmetric uncertainties are also frequently reported in the literature. Since it is envisioned that NUBASE2020 will be used by specialists in various application fields, such values are symmetrized prior to performing any statistical analyses, as described in section 3.3.

      In experiments where rare events were detected, for example in studies of super-heavy nuclei, the half-lives reported in different publications were not directly averaged. Instead, when the information presented in the literature was sufficient, the time information associated with the individual events was combined and analyzed, as prescribed by Schmidt et. al. [1984Sc13]. In recent review articles that deal with properties of super-heavy nuclei [2014Kh04,2016Fo10,2016Ho09,2017Og01] events from several experiments were combined together in order to determine the best values. We have adopted these half-life values, rather than averaging the individual results.

      In cases of long-lived nuclides that are of importance to metrology and other applications, all available experimental data were carefully examined, including values published by various metrology laboratories over many years. As a policy, we adopted the latest reported value by a particular laboratory, including the latest results published by Unterweger and Fitzgerald [10], which superseded the earlier assessment made by the same authors [11].

      An upper or a lower limit for the half-life value is given in Table I for nuclides identified using a time-of-flight technique. The following policies were implemented: a) for observed nuclides, the lower limit for the half-life is given in the place of the uncertainty field. However, such a value should be used with caution, since it may be far shorter than the actual level half-life. In order to avoid confusion, a somewhat more realistic estimate, derived from TNN and flagged with #, is also given (see for example the data entry for 44 Si). The same notation is also used for half-life limits of very long-lived (stable) nuclei (see for example the data entry for 188 Os); b) for nuclides that were looked for, but not observed, the upper limit is given in the place of the uncertainty field. For example, upper limits were estimated for a number of unobserved nuclides by F. Pougheon [1993Po.A], based on the time-of-flight information and the production yields expected from TNN (see for example the data entry for 21 Al).

      In the course of this work it was found that half-lives for double β -decaying nuclides were not always consistently given in ENSDF. Since the two-neutrino ground-state-to-ground-state transition is the dominant decay mode, only those experimental half-life values, or their upper-limits, are included in NUBASE2020. In a few cases, other partial lifetime data are also compiled and these are given as comments in Table I. No attempt was made to convert the half-life values given by different authors to the same statistical confidence level (CL). The compilations by Barabash [2020Ba.A,2011Ba28] were consulted in covering such decays.

      For nuclei in their ground or excited isomeric state whose half-lives were not directly measured, values from TNN were estimates and included in Table I, whenever possible. Such cases are flagged with the symbol ‘#’.

      • 2.4.   Spin and parity

    • Spin and parity values are presented with or without parentheses, based on “weak” or “strong” arguments, respectively, as adopted in ENSDF [12], but with one important exception. Since, it is a policy of NUBASE2020 to make a clear distinction between experimental and non-experimental information, parentheses are used only when the so-called “weak” arguments are based on experimental observations. In cases where the assignments are based on theoretical predictions or TNN, the values are presented without parentheses and they are flagged with the symbol ‘#’. This is in contrast to ENSDF, where values determined from theory or systematics are given in parentheses, and as a consequence, it is not possible to distinguish these tentative values from ones determined from experimental data. It should also be noted, that despite well-defined evaluation policies [12], there are a number of inconsistencies in ENSDF regarding the spin and parity assignments. Often, the proposed spins and parities reflect the interpretation of a particular ENSDF evaluator, rather than that of firm policy rules. As a result, assignments to similar states in neighboring nuclei are put in parenthesis by one evaluator, but not by another, although similar experimental information is available.

      There is a large amount of recent experimental data on directly measured spins for nuclei far from the line of stability, where the “in-source” (e.g. RILIS at ISOLDE (CERN) and TRILIS at ISAC (TRIUMF)) and “collinear” (e.g. CRIS at ISOLDE (CERN)) laser spectroscopy techniques were deployed. In the present work, we compiled the experimentally measured spins for 1062 states (827 ground states and 235 isomers) and the corresponding values are flagged in Table I with the symbol ‘*’. We have consulted previous compilations by Fuller [13], Otten [1989Ot.A] and McDonald [14], as well as recently measured values in the literature. Figures 4 and 5 show plots of the directly measured spins for the ground and isomeric states, respectively, as a function of N and Z.

      Figure 4.  Nuclear chart displaying the measured ground-state spins.

      Figure 5.  Nuclear chart displaying the measured isomeric-state spins.

      The experimental methods that are used for spin determination do not provide direct information about the parity of a given state. However, we have used additional spectroscopy data, such as l value in transfer reactions, hindrance factors in α decay, measured magnetic moments, as well as other spectroscopic information, in order to make such assignments in Table I.

      • 2.5.   Decay modes and their intensities

    • Figure 6 displays the main ground-state decay modes for all nuclei included in Table I.

      Figure 6.  Nuclear chart displaying the main decay mode for nuclei in their ground state.

      The most important policy in assembling the information about the decay modes and their intensities was to unambiguously establish whether a particular decay is energetically allowed, but not experimentally observed (represented by a question mark alone ‘?’, e.g. ‘IT?’ or ‘ α ?’, the question mark refers to the decay mode), and whether the decay is actually observed, but its intensity is not determined (represented by ‘ =?’, e.g. ‘IT =?’ or ‘ α =?’, the question mark refers to the branching intensity).

      In cases of multiple decay modes, normalization of primary intensities to 100% was made only when the competing decays were experimentally observed. Otherwise, no such corrections were made.

      Similarly to previous versions of NUBASE [1–4], β+ denotes a decay process that includes both electron capture, ε , and positron emission, e + , decays, so that one can symbolically write β+=ε+e+ . It should be made clear that this notation is not the same as that used in ENSDF, where the combination of both modes is labeled as ε+β+ . When the available decay energy is below 2m e ≃ 1022 keV, only electron capture decay mode is allowed, while above that value the two processes are in competition. In the latter case, the separated intensities are not always experimentally available and they are frequently deduced from model calculations. Following one of the general policies of NUBASE that experimental information is exclusively used whenever possible, only measured values for β+ , ε and e+ are included in Table I. By the same token, both electron capture-delayed fission ( ε SF) and positron-delayed fission ( e+ SF) are given with the same symbol β+ SF.

      For β -delayed particle decays, intensity relations were carefully considered. By definition, the intensity of a specific β -delayed particle decay is taken as a percentage of the main β -decay mode. For example, if the decay of the (A, Z) nuclide is described as ‘ β− = 100; β− n = 20’, this means that for 100 decays of the parent, 80 (A, Z+1) and 20 (A–1, Z+1) daughter nuclei are produced and that 100 electrons and 20 delayed neutrons are emitted.

      This notation also holds for more complex β -delayed particle emissions. For example, a decay described by ‘ β− = 100; β− n = 30; β− 2n = 20; β−α = 10’ corresponds to the emission of 100 electrons, 70 (30+2 × 20) delayed-neutrons and 10 delayed- α particles; and in terms of residual nuclides, to 40 (A, Z+1), 30 (A–1, Z+1), 20 (A–2, Z+1) and 10 (A–4, Z–1), respectively.

      In general, the number of neutrons emitted per 100 β− decays, Pn , can be written as:

      Pn=∑ii×β−in;

      and similar expressions can be written for β− -delayed α and proton emissions. The number of residual daughter nuclides (A, Z+1) populated via β− decay is then:

      β−−∑iβ−in−∑jβ−jα−…

      Sometimes, the primary (parent) β decay can populate several excited states in the daughter nuclide, which can further decay by particle emission. However, in a case where the ground state of the daughter nuclide decays also by the same particle emission, some authors included its decay in the value for the corresponding β -delayed particle intensity. It is a policy of NUBASE2020 to not use such an approach for two main reasons: a) the energies of delayed particles emitted from excited states are generally much higher compared to those emitted from the ground state, thus implying different subsequent processes; b) the characteristic decay times from excited states are related to the parent, whereas decays from the daughter's ground state are connected to the daughter nuclide itself. For example, 9 C decays via β+ emission to the ground state of the proton-unbound 9 B nuclide (feeding intensity of 54.1(1.5)% [2001Be51]) and to several excited states that are proton and/or α unbound. If one takes the β+ intensities to the excited states in 9 B from Ref. [2000Ge09] and renormalizes them to per 100 decays of the parent, then β+ p = 7.5(0.6)% and β+α = 38.4(1.6)% can be determined for 9 C. In a slightly different example, 8 B decays via β+ emission only to two excited, α -unbound states in 8 Be, but not to the 8 Be ground state. Thus, one may write β+ = 100% and β+α = 100%, and therefore, no net population of the 8 Be ground state.

      It should be pointed out that the percentages given in the Table I are related to 100 decays of the parent nuclei, rather than to the primary decay mode fraction. For example, the delayed-fission probability in the decay of 228 Np is given in the original article as 0.020(9)% [1994Kr13], but this value is relative to the ε process, which has an intensity of 60(7)%. Thus, the renormalized delayed-fission intensity is 0.020(9)% × 0.60(7) = 0.012(6)% of the total decay intensity.

      In addition to applying direct updates from the literature, partial evaluations completed by other authors were also considered in the evaluation of delayed particle data. For example, in compiling data for delayed proton- and α -branching intensities, the work of Hardy and Hagberg [1989Ha.A], Jonson and Riisager [15], Blank and Borge [16] and Pfützner et al. [17], where the corresponding physics was reviewed, as well as the recent compilation of Batchelder [18], were consulted. Similarly, data on β -delayed neutron emission probabilities that were recommended by a recent IAEA Coordinated Research Project [19] were also consulted.

      • 2.6.   Isotopic abundances

    • Isotopic abundances are given in the decay field of Table I with the symbol IS and the values were taken from the most-recent publication of Meija et al. [20]. In several cases the IS values are listed in Ref. [20] as an interval [a,b] , but in Table I they are given as IS = (a+b)/2 with a variance σ 2 = (b−a)2/12 (see section 3.2).

      • 2.7.   Year of discovery

    • Similarly to the previous version of NUBASE [3, 4], Table I includes information about the year of discovery for each nuclide in its ground or isomeric state. For the former, recommendations by Thoennessen [21] were adopted. Similar criteria were used when assigning the year of discovery for isomeric states.

      • 2.8.   References and Dissemination

    • The year of the ENSDF archival file that was consulted during the development of NUBASE2020 is given in Table I. The entry is left blank when information for a particular nuclide was not available in ENSDF.

      The bibliographical information used in NUBASE2020 is referenced by means of the “Nuclear Science Reference” (NSR) database [22] keynumber style. However, references quoted in Table I are abbreviated with the first two digits of the year of publication being omitted from the NSR-style keynumbers. They are followed by up to three one-letter codes which specify the added or modified physics quantities (see the Explanation of Table I).

      In cases where more than one reference was needed to describe a particular update, they were included as comments in Table I. No references were given for estimated values.

      The initials of the former and present evaluators, e.g. GAU (G. AUDI), HWJ (W. HUANG), FGK (F. KONDEV), MMC (M. MACCORMICK), SAR (S. NAIMI) WGM (M. WANG), AHW (A. WAPSTRA), were used as reference keys where it may not be clear that the re-interpretation of data was made by the NUBASE evaluators.

      In cases of directly measured spins, references are provided only to papers that were not included in the most-recent compilation of McDonald et al. [14].

      The complete reference list is given at the end of this issue (see AME2020, Part II), together with the references used in AME2020.

      The recommended data for the basic nuclear physics properties are also made available as an ASCII-formatted file (nubase.mas20) at the dissemination websites of the collaboration [23].

    3.   Policies of NUBASE2020

      3.1.   Trends in neighboring nuclei (TNN)

    • In general, NUBASE2020 contains numerical and bibliographical information for all known nuclei for which at least one property is experimentally known. However, it also includes results on yet unobserved nuclides, as well as data on properties (mostly excitation energy for isomers, half-lives and spins and/or parities) that are not yet measured. Such values are estimated from the systematics trends of a particular property in neighboring nuclei by ensuring a continuity in N, in Z, A, and in N−Z . This approach allowed to follow the behavior of a particular property as a function of N and Z in a consistent way and it proved beneficial in deducing values for other relevant properties. Similarly to AME2020, where masses estimated from Trends from the Mass Surface (TMS) are flagged with ‘#’, the same symbol is used in NUBASE2020 to indicate non-experimental information inferred from TNN. It should be pointed out, however, that deviations from TNN are expected when nuclear structure effects, such as deformation and/or shape changes, occur. Such data were taken into account to the best knowledge of the present authors.

      • 3.2.   Averaging procedure and uncertainties

    • It is a policy of NUBASE2020 to use one standard deviation as a representation of uncertainties associated with the recommended values. Unfortunately, authors of research articles do not always clarify the meaning of their reported uncertainties and, under such circumstances, these values are assumed to be one standard deviation. In several instances, uncertainties are not given at all and in such cases they were estimated by the evaluators, considering the limitations of the employed experimental method. When both the statistical and systematic uncertainties were reported in the literature, they were combined in a quadrature by the NUBASE2020 evaluators.

      Sometimes lower (l) and upper (u) limits of a particular quantity, q, are reported in the literature, e.g. q ∈ [l,u] . A policy of NUBASE2020 is that uniform probability distribution is assumed in such cases, which yields a mean value of m=(l+u)/2 and a standard deviation of σ = (u−l)/√12 ≃ 0.29 × (u−l) .

      When results from two or more independent measurements were reported in the literature, the corresponding values were weighted by their reported uncertainties and averaged. The weighted average value and its uncertainty are calculated as:

      ¯x±Δ¯x=N∑i=1wixi/N∑i=1wi±√1/N∑i=1wi

      		(3)

      where wi = 1/Δx2i and xi and Δxi are the value and its uncertainty reported in the ith experiment, and the summation is over all N experiments. For each average value the NORMALIZED CHI, χn (or ‘consistency factor’ or ‘Birge ratio’), defined as:

      χn=√1N−1N∑i=1wi(xi−¯x)2

      		(4)

      is also calculated.

      It is a policy of NUBASE2020 to use the weighted average result (equation 3) when χn is smaller or equal to 2.5. In cases where χn is larger than 2.5, but less or equal to 4, departure from the statistical result (equation 3) is allowed and the external uncertainty for the average value is adopted:

      ¯x±Δ¯x=N∑i=1wixi/N∑i=1wi±χn×√1/N∑i=1wi

      		(5)

      In rare cases when χn is larger than 4, all individual uncertainties are considered to be irrelevant and the arithmetic (unweighted) average is adopted:

      ¯x±Δ¯x=1NN∑i=1xi±√1N(N−1)N∑i=1(xi−¯x)2

      		(6)

      The values used in the statistical analysis of a particular quantity are given as comments in Table I. When contradictory (discrepant) results were identified in the literature, a great deal of attention was focused on establishing the reason for such discrepancies, and consequently, on rejecting (or correcting) the corresponding unreliable data prior to performing the statistical analysis. The reasons for such decisions are given as comments in Table I.

      • 3.3.   Symmetrization of asymmetric uncertainties

    • Experimental results are sometimes reported in the literature with asymmetric uncertainties, e.g. X+a−b , and it is a policy of NUBASE to symmetrize these uncertainties.

      Similarly to the previous version of NUBASE [1–4], the asymmetric uncertainty is associated with a two-piece normal distribution (sometimes called “split-normal distribution” or “Fechner distribution”), TN(X,a,b) , and the symmetrization is achieved by mapping this distribution into a normal (symmetric) distribution, N(μ,σ) , where μ is the mean value and σ is the standard deviation.

      The probability density function of a two-piece normal distribution is given as:

      f(x)={A×exp[−(x−X)2/2a2]ifx<X,A×exp[−(x−X)2/2b2]ifx<X

      		(7)

      It has a modal (most probable) value of x=X , a standard deviation b for x < X and a standard deviation a for x > X (see Figure 7), with A=(√π/2×(a+b))−1 . This distribution is formed by taking the left half of a normal distribution N(X,b) and the right half of a normal distribution N(X,a) and scaling them to give a common value of f(x) = A at the mode X (see Figure 7). The mean value and the variance of this distribution can be determined as [24]:

      Figure 7.  (dashed black) original Normal distributions, N(X,b) (left on X) and N(X,a) (right on X), associated with the measured quantity X+a−b ; (solid blue) a two-piece normal distribution TN(X,a,b) ; (solid red) the equivalent Normal (symmetric) distribution, N(m,σ) ; see section 3.3 for details.

      μ=X+√2/π×(a−b)

      		(8)

      σ2=(1−2/π)×(a−b)2+a×b

      		(9)

      The median value m, which divides the distribution into two equal areas is then:

      m={X+a√2×erf−1(a−b2a)ifa<b,X+b√2×erf−1(a−b2b)ifb<a.

      		(10)

      If one takes erf−1(z)≃√πz/2 then

      m−X≃√π/8×(a−b)≃0.6267×(a−b)

      		(11)

      In order to allow for a small non-linearity that appears for high values of m−X , equation 11 is modified to:

      m≃X+0.64×(a−b)

      		(12)

      Following the above approach, the two-piece normal distribution TN(X,a,b) is mapped into an equivalent normal (symmetric) distribution N(m, σ ) (see Figure 7) that have a mean value equal to the median value m (equation 12) and variance σ (equation 9). As a consequence, X+a−b is symmetrized to m ± σ and the latter is adopted in NUBASE2020.

      • 3.4.   Rounding policy

    • In general, values for properties presented in NUBASE2020 and their uncertainties are rounded off, even if unrounded ones were given in the literature or in ENSDF. However, for some very precise data, as well as for data that were deemed essential for traceability purposes (e.g. isotopic abundances), the precisions quoted in the original publications were retained.

      In cases where the two furthest-left significant digits in the uncertainty were larger than a given limit (set to 30 for the mass excess and excitation energy of isomers in order to be consistent with AME, and set to 25 for half-lives and branching ratios, as generally used in ENSDF), the adopted values and corresponding uncertainties were rounded off accordingly.

    4.   Conclusions and outlook

    • The NUBASE2020 evaluated nuclear data library contains the recommended values for the basic nuclear physics properties for all known nuclei, such as mass excess, excitation energy of the excited isomeric state, half-life, spin and parity, decay modes and their intensities, isotopic abundance (for stable nuclides), year of discovery, as well as the corresponding bibliographical information. It also contains information for yet unobserved nuclei whose properties were estimated by following the systematic trends in neighboring nuclei.

      One of the main requirements in the development of NUBASE2020 was to cover the available experimental data as completely as possible and to provide proper references to all experimental results, especially for cases that are not included in ENSDF or in other topical evaluations. Such a traceability would allow any user to promptly review the recommended data and, if necessary, to undertake a re-evaluation.

      NUBASE2020 is an integral part of AME2020 and the synchronization of these two libraries allows better homogeneity of all experimental data to be achieved. Furthermore, assignments of isomeric states and determination of their excitation energies were put on a firm basis and the data were improved.

      In the future development of NUBASE, it is envisioned to include additional nuclear properties, such as magnetic and quadrupole moments, charge-radii and isotope shifts, cross sections of importance to nuclear astrophysics applications, as well as additional decay properties of relevance to energy and non-energy applications, in order to better serve the broader nuclear physics community.

    5.   Acknowledgments

    • 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) and in part by the National Key Research and Development Program of China (Grant No. 2016YFA0400504) and 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.

      We thank many colleagues who responded to our queries about the experimental data, as well as those who sent us preprints of their work prior publication. We also thank D. Lunney and B. Kay for the careful reading of the manuscript and useful comments.

Reference (24)

目录

Link
IOPScience
SCOAP3
arXiv
Chinese Physical Society
Journal information
Introduction
Editorial Board
Others
Subscribe
Contact us
QQ: 1307685413
Tel: +86-010-88235947
Fax: +86-010-88233126
E-mail: cpc@ihep.ac.cn

  • CPC Website

  • IOP Website

  • CPC WeChat

Copyright © Institute of High Energy Physics, Chinese Academy of Sciences, 19B Yuquan Road, Beijing 100049, China 京ICP备05002789号-1

Supported by: Beijing Renhe Information Technology Co. Ltd  E-mail: info@rhhz.net

/

DownLoad:  Full-Size Img  PowerPoint
Return
Return