Nucleus++:a new tool bridging AME and NuBAsE for advancing nuclear data analysis

The newly developed software,Nucleus++,is an advanced tool for displaying basic nuclear physics properties from NubAsE and integrating comprehensive mass information for each nuclide from Atomic Mass Evaluation.Additionally,it allows users to compare experimental nuclear masses with predictions from different mass models.Building on the success and learning experiences of its predecessor,Nucleus,this enhanced tool introduces improved functionality and compatibility.With its user-friendly interface,Nucleus++was designed as a valuable tool for scholars and practitioners in the field of nuclear science.This article offers an in-depth description of Nucleus++,highlighting its main features and anticipated impacts on nuclear science research.

The NUBASE2012 evaluation of nuclear properties

This paper presents the NUBASE2012 evaluation that contains the recommended values for nuclear and decay properties of nuclides in their ground and excited isomeric （T1/2≥ 100 ns） states. All nuclides for which some experimental information is known are considered. NUBASE2012 covers all up to date experimental data published in primary （journal articles） and secondary （mainly laboratory reports and conference proceedings） references, together with the corresponding bibliographical information. During the development of NUBASE2012, the data available in the ＂Evaluated Nuclear Structure Data File＂ （ENSDF） database were consulted, and critically assessed of their validity and completeness. Furthermore, a large amount of new and somewhat older experimental results that were missing in ENSDF were compiled, evaluated and included in NUI3ASE2012. The atomic mass values were taken from the ＂Atomic Mass Evaluation＂ （AME2012, second and third parts of the present issue）. In cases where no experimental data were available for a particular nuclide, trends in the behavior of specific properties in neighboring nuclei （TNN） were examined. This approach allowed to estimate, whenever possible, values for a range of properties, and are labeled in NUBASE2012 as ＂non-experimental＂ （flagged ＂#＂）. Evaluation procedures and policies that were used during the development of this database are presented, together with a detailed table of recommended values and their uncertainties.

The NUBASE2016 evaluation of nuclear properties

This paper presents the NUBASE2016 evaluation that contains the recommended values for nuclear and decay properties of 3437 nuclides in their ground and excited isomeric （T1/2〉 100 ns） states. All nuclides for which any experimental information is known were considered. NUSASE2016 covers all data published by October 2016 in primary （journal articles） and secondary （mainly laboratory reports and conference proceedings） references, together with the corresponding bibliographical information. During the development of NUBASE2016, the data available in the ＂Evaluated Nuclear Structure Data File＂ （ENSDF） database were consulted and critically assessed for their validity and completeness. Furthermore, a large amount of new data and some older experimental results that were missing from ENSDF were compiled, evaluated and included in NUBASE2016. The atomic mass values were taken from the ＂Atomic Mass Evaluation＂ （AME2016, second and third parts of the present issue）. In cases where no experimental data were available for a particular nuclide, trends in the behavior of specific properties in neighboring nuclides （TNN） were examined. This approach allowed to estimate values for a range of properties that are labeled in NUBASE2016 as ＂non-experimental＂ （flagged ＂#＂）. Evaluation procedures and policies used during the development of this database are presented, together with a detailed table of recommended values and their uncertainties.

ATOMIC AND NUCLEAR PROPERTIES OF MATERIALS

Table 6.1 Abridged from pdg. ibl.gov/AtomicNuclearProperties by D. E. Groom （2007）. See web pages for more detail about entries in this table including chemical formulae, and for several hundred other entries. Quantities in parentheses are for gases at 20℃ and 1 atm, and square brackets indicate evaluation at 0℃ and 1 atm. Boiling points are at 1 atm.

Extraction of Nuclear Matter Properties from Nuclear Masses by a Model of Equation of State

The extraction of nuclear matter properties from measured nuclear masses is investigated in the energy density functional formalism of nuclei.It is shown that the volume energy a1 and the nuclear incompressibility Ko depend essentially on μnN -+- pZ - 2EN,whereas the symmetry energy J and the density symmetry coefficient L as well as symmetry incompressibility Ks depend essentially on μn - μp,where μp ＝μp - Ec/ Z,μn and μp are the neutron and proton chemical potentials respectively,EN the nuclear energy,and Ec the Coulomb energy.The obtained symmetry energy is J ＝ 28.5 MeV,while other coefficients are uncertain within ranges depending on the model of nuclear equation of state.

Revisiting the island of hexadecapoledeformation nuclei in the A≈150 mass region:focusing on the model application to nuclear shapes and masses

Based on the potential-energy-surface calculation,the impact of different deformation degrees of freedom on a single-particle structure and binding energies in nuclei around^(152)Nd,located on one of the hexadecapole-deformation islands,is analyzed in a multi-dimensional deformation space.Various energy maps,curves and tables are presented to indicate nuclear properties.The calculated equilibrium deformations and binding energies with different potential parameters are compared with experimental data and other theories.It is found that the inclusion of the hexadecapole deformations,especially the axial one,can improve the theoretical description of both nuclear shapes and masses.In addition,our calculated potential-energy curve shows that a critical deformation-point,β_(2)≈0.4,exists—the triaxial(hexadecapole)deformation effect can be neglectable but the hexadecapole(triaxial)one plays an important role before(after)such a critical point.

The NUBASE2020 evaluation of nuclear physics properties

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.

Commissioning of a high-resolution collinear laser spectroscopy apparatus with a laser ablation ion source

Collinear laser spectroscopy is a powerful tool for studying the nuclear spins,electromagnetic moments,and charge radii of exotic nuclei.To study the nuclear properties of unstable nuclei at the Beijing Radioactive Ion-beam Facility(BRIF)and the future High Intensity Heavy-ion Accelerator Facility(HIAF),we developed a collinear laser spectroscopy apparatus integrated with an offline laser ablation ion source and a laser system.The overall performance of this state-of-the-art technique was evaluated,and the system was commissioned using a bunched stable ion beam.The high-resolution optical spectra for the 4s ^(2)S_(1/2)→4p^(2)P_(3/2)(D2)ionic transition of ^(40;42;44;48)Ca isotopes were successfully measured.The extracted isotope shifts relative to ^(40)Ca showed excellent agreement with the literature values.This system is now ready for use at radioactive ion beam facilities such as the BRIF and paves the way for the further development of higher-sensitivity collinear resonance ionization spectroscopy techniques.

Nuclear structure and decay modes of Ra isotopes within an axially deformed relativistic mean field model

We examine the structural properties and half-life decay of Ra isotopes within the axially deformed Relativistic Mean-Field（RMF）theory with NL3 force parameters.We work out the binding energy（BE）,RMS radii,two-neutron separation energies（S（2n））,and some other observables.The results are in good agreement with the finite-range droplet model（FRDM）and experimental results.Considering the possibility of neutron magic number,theα-decay and cluster decay half-lives of Ra isotopes are calculated systematically using the Q-values obtained from the RMF formalism.These decay half-life calculations are carried out by taking three different empirical formulae.The calculated decay half-lives are found to be highly sensitive to the choice of Q-values.Possible shell or sub-shell closures are found at daughter nuclei with N=128 and N=126 when alpha and 8Be,12C,18O respectively are emitted from Ra isotopes.Though the cluster radioactivity is affected by the shell closure of parent and daughter,a long half-life indicates the stability of the parent,and a small parent half-life indicates that the shell stability of the daughter against decay.