Atomic Data and Nuclear Data Tables最新文献

Spanning the center-of-mass energy range of 10⁻⁴ to 10${}^8\mathrm{eV}$, presented here are recommended integral and differential cross sections for elastic scattering in collisions of protons with atomic hydrogen. The recommended values have been determined by analysis of results of three primary theoretical methods with overlapping regimes of applicability within this broad range of collision energies. With comparison to data available in the literature and study of the numerical and physical convergences of the calculations, uncertainty quantification of the results has been made, which in turn aids uncertainty quantification of the astrophysical and other environment simulations the data is aimed at enabling. Along with other data for processes including excitation, ionization, and charge transfer, the present data support improved transport modeling of the passage of protons through atomic hydrogen, describing energy loss, charge change, secondary electron production, and photon emission.

The energy levels of 1s², 1s2s, and 2s2p configurations for He-like ions ($4\le Z\le 54$) are calculated using the multi-configuration Dirac–Hartree–Fock​ methods. The transition energies, transition rates, and oscillator strengths of 2s2p$\to$1s² and 2s2p$\to$1s2s are also calculated. A parallel calculation based on the Dirac–Fock–Slater method with a local central potential is performed using the Flexible Atomic Code to cross-check the accuracy of the data. The Breit interaction and quantum electrodynamics effects, including self-energy and vacuum polarization, are included as perturbations in these calculations. The average relative standard deviation of the energy levels from the available NIST data is about 0.2% for both methods. The transition energies and rates are in reasonable agreement with other available theoretical and experimental data, and the consistency between the transition energies calculated by the two methods reaches 99.9%. These results are expected to help future investigations on double K-shell vacancy decays of He-like ions.

This work is an update of the 1998 publication by Singh et al. [1] and reviews the log $ft$ values for all the known $\beta$-decay branches ($\beta$−, $\beta$＋/EC). Furthermore, an update of all $Q$-values (from AME2020  [2]), as well as a recalculation of all the log $ft$ values (through BetaShape code [3], [4]) has been conducted using relevant data in the ENSDF database, as well as in newer literature. Only those cases have been considered in this review, where the beta transitions occur between levels of firm single spin assignments (86% of the transitions), and with probable single spin assignments (14% of the transitions), but with firm parity assignments for all the transitions. Weak $\beta$ branches of $<$1% intensity in complex decay schemes have generally been omitted. Out of a total of 26 318 $\beta$ transitions extracted from the ENSDF database and current literature, data for only 4038 $\beta$ transitions survived the filtering criteria in the present review. The log $ft$ values in $\beta$ decay, spanning about 21 orders of magnitude, have been classified into allowed and forbidden categories according to the classification scheme of Konopinski [5]. All log $ft$ values have been deduced using the BetaShape code with new developments presented in this study. A very few number of log $ft$ values for very low-energy beta transitions ($<$5 keV) survived the cut criteria and are briefly discussed in terms of atomic overlap corrections. Also tabulated and briefly discussed are seven superallowed cases with $\Delta$T = 0, T${}_z$(parent) = −2, while a known case for ²⁸S to ²⁸P has been omitted as reliable EC/$\beta$＋feeding to the analog state in ²⁸P cannot be assigned due to lack of adequate experimental and detailed data for this decay. Centroid, width, minimum and maximum values for each category have been deduced. Uncertainties have been estimated and are also given. For literature coverage in the present review, see discussion in text.

A new expression for a calculation of the pre-neutron emission average total kinetic energy of fission fragments (TKE), which takes into account the dependence of TKE on both $Z^2/A^{1/3}$ and the excitation energy of the fissioning nuclei, is found using the 728 experimental values of the TKE. These 728 values of TKE for 115 fissioning nuclei with the numbers of proton and nucleons in the ranges $48\le Z\le 120$ and $78\le A\le 302$ are measured by various experimental groups in different reactions at various excitation energies of the fissioning nuclei. The dependence of the TKE on the excitation energy of the fissioning nuclei is clearly shown for many nuclei. The account of the excitation energy dependence of the TKE leads to the smallest value of the root-mean-square deviation between the experimental and theoretical TKE values.

We aim to investigate atomic properties of Sb-like sequence: Sb I, Te II, I III, Xe IV, and Cs V. The multiconfiguration Dirac–Hartree–Fock and relativistic configuration interaction methods, which are implemented in the general-purpose relativistic atomic structure package GRASP2018, are used in the present work. The lowest energy levels of the $5s^{2}5p^3$, $5s5p^4$, $5p^5$, $5s5p^{3}5d$, and $5s^{2}5p^2\{6s,7s,6p,7p,5d,6d,4f\}$ configurations and electric dipole, magnetic dipole, and electric quadrupole transitions between states of these configurations are computed. Accuracy of energy levels are evaluated by comparing it with the National Institute of Standards and Technology Atomic Spectra Database recommended values and with other methods. Accuracy of transitions data are investigated using quantitative and qualitative evaluation method.