Comparative analysis on total cross sections is performed on several leading quantum-mechanical perturbative boundary-proper theories for single charge-exchange in four-body heavy particle collisions at intermediate and high impact energies. These are the boundary-corrected first Born (CB1-4B), the four-body continuum distorted wave (CDW-4B), the boundary-corrected continuum intermediate state (BCIS-4B) and the Born distorted wave (BDW-4B) methods. The present applications are made for direct and inverse processes for which these methods employ different analytical calculations and algorithms in the corresponding computer programs. To cross-validate such varieties, the principle of detailed balance is advantageously explored to correlate the total cross sections for direct and inverse collisions. In this way, it is shown numerically that detailed balance is fully satisfied for all the four methods. To accurately describe the examined encounters, the appropriate solutions of four-body quantum-mechanical problems with four dynamically active particles (two nuclei and two electrons) are required. The first-order methods (e.g. CB1-4B) are based on one-step pathways with only the projectile–target interactions. The second-order methods (e.g. CDW-4B, BCIS-4B, BDW-4B) describe two-step processes via target ionization followed by capture of the emitted electron. The ejected electron must have a high momentum in order to be captured by a fast projectile. This ionization-capture mechanism is a quantum-mechanical analogue of the classical Thomas double scattering. It is suggested that detailed balance should beneficially be employed as a consistency check also in other distorted-wave computations (direct vs. inverse processes, with the underlying juxtaposition: prior vs. post transition amplitudes and static vs. dynamic correlations).
We updated the atomic energy tables of Visscher and Dyall to reflect contemporary developments in nuclear physics and chemistry. To achieve this objective more conveniently, a newly developed, highly accurate Gaussian basis set (single-family exponent even-tempered 80 (SFXE80)) was adopted instead of numerical basis functions in the Dirac–Hartree–Fock calculations. After confirming sufficient accuracy through a comparative assessment with numerical basis functions, the SFXE80 basis set was used to construct the updated total energy tables. Nuclear charge distributions were modeled using the homogeneous charged sphere, Gaussian, two-parameter Fermi (2pF), and augmented Gaussian 12 (AG12) models. A novel semi-analytical formulation was developed to evaluate the nuclear attraction integrals with Gaussian basis functions using the 2pF nuclear charge distribution. Furthermore, the AG12 parameters were fitted to align with the 2pF model definitions used in this study.
In this paper we present a large-scale sensitivity study of reaction rates in the s and i process. We identified all rates with the highest absolute sensitivity on the production of each element. In addition, the effect of the radioactive decays on the abundances during the time between the end of the nucleosynthesis and the actual observation is considered.
Contemporary theoretical descriptions of nuclear structure rely mainly on microscopic, single-particle frameworks often in competition with collective degrees of freedom, especially when deformation plays a dominant role. Such phenomena are prominent in the rare-earth region, where rotational band structures and enhanced electric quadrupole transitions are systematically examined. The Confined β-Soft (CBS) rotor model, introduced by N. Pietralla and O.M. Gorbachenko, bridges the gap between the X(5) critical point and the rigid-rotor limit in the region where the R4/2=E(4+)/E(2+) ratio lies between 2.904 and 3.333. In the present work, the CBS framework is employed to calculate ground-state band energies, associated B(E2) transition rates, and β-band excitations of even–even nuclei in the rare-earth region. The theoretical results are systematically compared with available experimental data, and predictions are provided for nuclear observables that have not yet been measured, offering guidance for future experimental investigations.
Theoretical photoionization cross-sections and angular distribution parameters for valence and subvalence shells of the elements from La to Sm are calculated with account for intrachannel and interchannel interactions for the energy region from threshold up to 30 Ry. Many-electron effects were accounted for within the framework of RPAE (Random Phase Approximation with Exchange) method, which is extended for average terms of unfilled shells. Calculations demonstrate a strong influence of 4f ionization on partial photoionization cross-sections sigma(5 s), and sigma(6s ) near 4f threshold and strong resonances in all partial photoionization cross-sections due interaction with the excitation 4d -> 4f.
Ion-atom collision dynamics are fundamental to a broad spectrum of physical processes, spanning plasma physics, astrophysics, controlled thermonuclear fusion, and gas-phase chemical reactions. Among these, interactions between hydrogen ions and noble gases - articularly neon - are especially valuable as benchmark systems, owing to their comparatively simple electronic structure and their frequent occurrence in both laboratory plasmas and astrophysical media. In this work, we investigate the mobility of H+ ions in their ground state as well as their first and second excited states as they drift through a neon buffer gas, while also examining the influence of hydrogen isotopes (D+ and T+) on the resulting transport properties. The calculations are performed within the framework of the three-temperature theory for solving the Boltzmann kinetic equation, utilizing quantum-mechanically derived transport cross sections at low temperatures. The computed mobility values are compared with existing theoretical predictions and experimental measurements, demonstrating good agreement across the studied range.
Accurate nuclear cross-section data for proton-induced reactions on zinc are essential for assessing production routes of medically relevant radionuclides and for benchmarking nuclear reaction models. In this work, experimental excitation functions for natZn(p,x) reactions were determined in the proton energy range of 5-60 MeV. The investigated radionuclides comprise 57,58,60Co, 61,64,67Cu, 66,67,68Ga, and 62,65,69mZn, including both established and emerging isotopes of medical interest, activation assessment, and nuclear data evaluation. The measurements were carried out using the stacked-foil activation technique followed by high-resolution gamma-ray spectrometry. The resulting cross sections were systematically compared with previously reported experimental data and with theoretical predictions obtained using TALYS-2.2. Overall, good agreement with the most literature datasets was observed within the experimental uncertainties. The present dataset provides a comprehensive and consistent set of excitation functions over a broad energy interval, extending and refining the available experimental database for natZn(p,x) reactions. These results contribute to improved reliability in nuclear data evaluation, reaction modelling, and production planning for clinically relevant and prospective medical radionuclides.
The scaled distorted wave (sDW) approximation is used to study electron-impact ionization cross sections for energy levels of the ground 4d5 configuration and the metastable 4d45s and 4d35s2 configurations of the Mo+ ion. The sDW cross sections are obtained by applying scaling functions to the direct ionization and excitation cross sections calculated using the distorted wave (DW) approximation. Study demonstrates fairly good agreement to experimental data for the lowest energy levels of the 4d5 and 4d45s configurations. The direct ionization from these energy levels contributes 60%-80% to the total ionization process at peaks of the cross sections. Excitations from the 4p, 4d, and 5s subshells are analyzed in this work. Convergence of the excitation-autoionization channels is examined by including the excitations up to shells with n 30 and l 4.
In the present study, we undertook a comprehensive compilation and critical reassessment of >740 reported measurements spanning over five decades, concerning six K-shell X-ray intensity ratios: K alpha(2)/K alpha(1), K beta (y) (1)/K alpha 1, K beta(2)/K alpha(1), K beta(y) (2)/K alpha(1), K beta (y)( 2)/K beta (y)( 1), and K beta(3)/K beta(1), for elements with atomic numbers in the range Z =13 (Al) and Z = 99 (Es). The collected data were systematically organized in tabular form, and for each element, weighted mean values were derived, thereby establishing a sturdier baseline for cross-comparison throughout the dataset. Based on these weighted values, semi-empirical trends were delineated by fitting polynomial functions as a function of the atomic number. Complementing this survey of experimental results, we performed 93 additional calculations employing the multiconfiguration Dirac-Fock (MCDF) method, explicitly incorporating relativistic effects. Standard deviations were represented graphically, enabling the identification of global trends while simultaneously highlighting anomalous data points that may warrant re-measurement. Among the investigated ratios, K alpha(2)/K alpha(1)and K beta(3)/K beta(1) exhibited the most consistent behavior across the elemental sequence. Conversely, K beta(2)/K alpha(1) displayed significant dispersion at higher atomic numbers, most plausibly attributable to instrumental constraints such as spectral line overlap. The remaining ratios occupied an intermediate position, with discrepancies often traceable to a limited number of individual studies. Overall, this work provides a renewed perspective on K-shell X-ray intensity ratios. By integrating an extensive review of prior measurements with semi-empirical adjustments and newly generated MCDF calculations, we establish a consolidated reference set intended to support future experimental applications and theoretical de velopments in atomic physics.
we calculate the nonrelativistic energies of the nD states (3 <= n <= 10) of lithium atom using the Rayleigh-Ritz variational method in Hylleraas coordinates, incorporating a zeroth-order wave function. The leading-order relativistic and quantum electrodynamics (QED) corrections are evaluated perturbatively, while higher-order QED effects are estimated. Our results provide the most accurate theoretical values to date for the ionization energies, fine-structure splittings, and nD-2P transition frequencies of these states. When compared with available experimental data, our results show excellent agreement in some cases, but significant discrepancies in others. These differences suggest that the uncertainties in certain experimental results may have been underestimated. Furthermore, our theoretical predictions surpass the precision of existing experimental data by at least one order of magnitude in all cases. As such, they serve as benchmark values for future experimental and theoretical studies of the lithium atom. In addition, high precision oscillator strengths for transitions between n ' P and nD states with 2 <= n ' <= 10 and 3 <= n <= 10 are also obtained.
We present a systematic calculation of the Huff factor for nuclei with atomic numbers (Z) in the range of 6≤Z≤94. The Huff factor quantifies the increase in the partial lifetime of the decay-in-orbit (DIO) of the muonic atom and serves as an essential correction factor for extracting the nuclear muon capture rate from the measured lifetimes of the muonic atom. However, previous calculations typically provided only the atomic number dependence and neglected isotope dependence—an assumption whose reliability had not been examined, despite its importance for a comprehensive understanding of the nuclear muon capture rate. In this work, we calculate the Huff factor using nuclear charge distributions obtained from a fully self-consistent microscopic nuclear structure model that incorporates pairing and deformation effects. The resultant Huff factors exhibit a monotonic decrease with increasing Z, while the isotope dependence is found to be small. Our results also show good agreement with previous calculations, supporting the reliability of the present framework. The comprehensive set of Huff factors presented here constitutes the first unified values currently available and will serve as a basis for future evaluations of muon nuclear data.
Westcott g factors are used in Neutron Activation Analysis (NAA) and Prompt Gamma-ray Activation Analysis (PGAA) to evaluate the impact of non-1/v behavior in the neutron-capture cross sections of certain nuclei on activation product yields. This non-1/v behavior arises from the presence of neutron resonances in the neutron-capture cross sections that overlap with the source neutron spectrum at low (< 5 eV) energies. Historically, Westcott g factors that have been cataloged for NAA and PGAA applications are the result of calculations that assume a Maxwellian neutron flux distribution with a given temperature. In this work, we use this approach with updated neutron-capture cross sections from the Evaluated Nuclear Data File, version VIII.1 (ENDF/B-VIII.1) to tabulate Westcott g factor values for a broad range of Maxwellian distribution temperatures, comparing the results against currently-available g factors from International Atomic Energy Agency tables and other sources. It was discovered during this analysis that the use of guided thermal and cold-neutron beams at certain facilities necessitates an approach for evaluating Westcott g factors based on arbitrary non-Maxwellian spectra. In this paper, we present an approach for calculating g factors with user-specified neutron spectra, and we demonstrate these methods to obtain Westcott g-factors for guided-and cold-neutron beams at the Budapest Research Reactor and the Forschungsreaktor M & uuml;nchen II reactor. As part of this work, open-source software has been developed that can be used to perform these calculations for applications in PGAA and NAA experiments.
We present a calculation of the low-energy phase shift and scattering length for the strontium atom, using the Dirac-Coulomb Hamiltonian augmented with a model polarization potential. The scattering length is extracted from the asymptotic behavior of the wave function in the zero-energy limit. To evaluate the reliability of our results, we compare them with existing experimental data and previous theoretical predictions. Bound-state properties are obtained using a multiconfigurational approach with the GRASP2018 package, while continuum states are computed with a modified version of the GRASP code, known as GRASPC, recently published in Computer Physics Communications.
This study presents new tables for Stevens' multiplicative factors < L||beta||L > and < L||gamma||L > for ions with a 4f(n) configuration. The tables, denoted as Table 4 and Table 5, provide values for these factors that were calculated for 4f(n) ions in the |L, L-z, S, S-z > basis, which distinguishes them from typically used tables expressed in the |J, J(z)> basis and commonly truncated for 4f(n) ions. These values are crucial for describing the magnetic and electric properties of compounds containing lanthanide ions. To the best of our knowledge, these values have not been explicitly tabulated in any previous publication. The tables may help in the analysis of experimental data and the modeling of magnetic and electric properties for ions with a 4f(n) configuration.
The authors would like to thank Prof. Dr. Ulf Litz & eacute;n, University of Lund, Sweden, for making available the UV-FT spectrum, on which most of our investigations were performed. Open Access Funding was provided by Graz University of Technology.
This paper presents an overview of the latest results of measuring differential and integrated gamma-ray emission cross sections in reactions induced by 14.1 MeV neutrons for 16 elements (Li, B, N, F, Na, Mg, S, Cl, K, V, Mn, Co, Ni, Cu, Zn, Sn) carried out within the framework of the TANGRA (TAgged Neutrons and Gamma RAys) project. The experiments were performed using high-resolution gamma-ray detectors based on LaBr3(Ce) crystals and high-purity germanium (HPGe) detectors. A distinctive feature of this work was the use of the tagged neutron method to determine the number of neutrons hitting the sample and background rejection by time of flight. Differential cross sections were obtained in the angular range of 12-89 degrees, with subsequent expansion into Legendre polynomials of even degree to obtain the integrated cross sections.
Currently, 1917 nuclear isomers with half-lives longer than 100 ns have been discovered in 1310 different nuclides and 103 different elements. While the physical properties of isomers have been compiled before, this is the first compilation of the isomer discoveries. For each isomer the reference, year, laboratory and country are documented.
The results of calculations for the total energies, ionization energies, and one-electron binding energies for ground-state configurations of tungsten ions W I to W73+ are presented. Calculations are performed in the intermediate coupling scheme on the basis of the Dirac-Fock method with taking into account the Breit and quantum electrodynamics corrections. Within the framework of the configuration interaction approach, all relativistic configurations corresponding to the non-relativistic one are used to obtain total energies and wave functions in the intermediate coupling scheme. The ionization energies are calculated as differences between the total energies of the neighboring ions with charges differing by one unit. Comparisons are given with other available data.
Multiconfiguration Dirac-Hartree-Fock (MCDHF) and relativistic configuration interaction (RCI) methods have been used to calculate the energies of 1s22s22p 2P1/2,3/2 levels for the boron isoelectronic sequence with Z = 5-92. It is found that the fine-structure splitting can be corrected by adding the frequency-dependent part of the Breit correction, which can result in a significant improvement of up to about 0.2% especially for high-Z B-like ions. We suggest that the fine-structure 1s22s22p 2P3/2-2P1/2splittings in the boron isoelectronic sequence could be used to accurately test current theoretical methods to calculate the corrections of Breit and quantum electrodynamic (QED) effects. As far as the QED effects are concerned, the self-energy correction dominates for the low-and mid-Z range (Z = 5-79), but then decreases to change sign for Z = 87 and meanwhile after Z = 80 the vacuum polarization is the leading term. It is also found that the frequency-dependent part of Breit correction strongly cancel out the SE and the total QED effects for Z = 56 and 60, respectively. This allows us to accurately test VP and Breit correlation for these ions. The uncertainties of the frequency-independent Breit correction and Coulomb correlation are expected to be at least 2 orders of magnitude smaller than the QED and frequency-dependent part of Breit corrections for intermediate-and high-Z B-like ions. Finally, the present M1 and E2 transition probabilities between the fine-structure levels are calculated and they are in good agreement with other theoretical and experimental results, especially for the mid-and high-Z ions.
