A5074969271- Nuclear physics research studies
- Quantum Chromodynamics and Particle Interactions
- Nuclear Physics and Applications
- Astronomical and nuclear sciences
- Nuclear reactor physics and engineering
- Atomic and Molecular Physics
- Quantum, superfluid, helium dynamics
- Advanced Chemical Physics Studies
- Rare-earth and actinide compounds
- Cold Atom Physics and Bose-Einstein Condensates
- Nuclear Materials and Properties
- Particle physics theoretical and experimental studies
- Pulsars and Gravitational Waves Research
- Advanced NMR Techniques and Applications
- Atomic and Subatomic Physics Research
- High-pressure geophysics and materials
- Physics of Superconductivity and Magnetism
- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Quantum chaos and dynamical systems
- High-Energy Particle Collisions Research
- Cold Fusion and Nuclear Reactions
- Quantum and electron transport phenomena
- Nuclear and radioactivity studies
- Geophysics and Gravity Measurements
State Grid Corporation of China (China)
2025
State Key Laboratory of Nuclear Physics and Technology
2015-2024
Peking University
2015-2024
Shenyang Institute of Computing Technology (China)
2024
University of Chinese Academy of Sciences
2024
Institute of Modern Physics
2023-2024
Chinese Academy of Sciences
2014-2024
University of Jinan
2024
Institute of Theoretical Physics
2014-2015
University of Tennessee at Knoxville
2008-2013
There has been much recent interest in nuclear fission, due part to a new appreciation of its relevance astrophysics, stability superheavy elements, and fundamental theory neutrino interactions. At the same time, there have important developments on conceptual computational level for theory. The promising theoretical avenues were subject workshop held at University York October 2019; this report summarises findings recommendations.
MADNESS (multiresolution adaptive numerical environment for scientific simulation) is a high-level software solving integral and differential equations in many dimensions that uses fast harmonic analysis methods with guaranteed precision are based on multiresolution separated representations. Underpinning the capabilities powerful petascale parallel programming aims to increase both programmer productivity code scalability. This paper describes features of briefly discusses some current...
Fission product yields are key infrastructure data for nuclear applications in many aspects. It is a challenge both experimentally and theoretically to obtain accurate complete energy-dependent fission yields. We apply the Bayesian neural network (BNN) approach learn existed predict unknowns with uncertainty quantification. demonstrated that BNN particularly useful evaluations of when incomplete experimental available. The results quite satisfactory on distribution positions energy dependencies
To synthesize new superheavy elements, the accurate prediction of nuclear masses nuclei is essential for calculations reaction Q values, neutron separation energies and α-decay energies, which are important estimating beam survival probabilities also identifications. In this work, we include existing in fitting procedure extended Skyrme density functionals as corresponding not available. Systematic well reproduced with a standard deviation 0.24 MeV. The high quality make it feasible direct...
Using an effective potential that is based on the Skyrme-Hartree-Fock mean-field model, systematic \ensuremath{\alpha}-decay properties of even-even heavy and superheavy nuclei have been investigated. Calculations do not raise any adjustable parameter. The obtained half-lives agree reasonably well with experimental data. characteristics deformation effect \ensuremath{\alpha} decay are discussed.
We study the bulk deformation properties of Skyrme nuclear energy density functionals (EDFs). Following simple arguments based on leptodermous expansion and liquid drop model, we apply functional theory to assess role surface symmetry in nuclei. To this end, validate commonly used parametrizations against data excitation energies superdeformed band heads Hg Pb isotopes fission isomers actinide After subtracting shell effects, results our self-consistent calculations are consistent with...
Recent experiments [Phys. Rev. Lett. 123, 092503 (2019); Phys. 118, 222501 (2017)] have made remarkable progress in measurements of the isotopic fission-fragment yields compound nucleus $^{239}\mathrm{U}$, which is great interests for fast-neutron reactors and benchmarks fission models. We apply Bayesian neural network (BNN) approach to learn existing evaluated charge infer incomplete $^{239}\mathrm{U}$. found that two-layer BNN improved compared single-layer overall performance. Our results...
The coordinate space formulation of the Hartree-Fock-Bogoliubov (HFB) method enables self-consistent treatment mean-field and pairing in weakly bound systems whose properties are affected by particle continuum space. Of particular interest neutron-rich, deformed drip-line nuclei which can exhibit novel associated with neutron skin. To describe such theoretically, we developed an accurate 2D lattice Skyrme-HFB solver {\hfbax} based on B-splines. Compared to previous implementations, made a...
A systematic study of fission-barrier dependence on excitation energy has been performed using the self-consistent finite-temperature Hartree-Fock + BCS (FT-HF BCS) formalism with SkM${}^{*}$ Skyrme density functional. The calculations have carried out for even-even superheavy nuclei $Z$ ranging between 110 and 124. For an accurate description fission pathways, effects triaxial reflection-asymmetric degrees freedom fully incorporated. Our survey demonstrates that isentropic barriers changes...
The quasiparticle energy spectrum of the Hartree-Fock-Bogoliubov (HFB) equations contains discrete bound states, resonances, and nonresonant continuum states. We study structure unbound weakly nuclei within several methods that do not rely on imposing scattering or outgoing boundary conditions. Various approximations are examined to estimate resonance widths. It is shown stabilization method works well for all HFB resonances except very narrow ones. Thomas-Fermi approximation has been be...
The systematic quenching of spectroscopic factors in terms separation energy asymmetry single-nucleon knockout reactions remains a puzzle. We propose core screening effect to consider the hindrance when strongly bound nucleons projectile nucleus are removed by heavy-ion target. is simulated as density dependent suppression single-particle wave functions inside projectile. Our study shows that parameterized can significantly reduce isospin dependence factors, offering insights into nuclear...
The total-Routhian-surface (TRS) calculation provides a powerful theoretical tool to describe the collective rotations of nuclei. It gives straightforward way determine nuclear deformation which can change with increasing rotational frequency. In most cases, however, TRS calculations conventional pairing approach (e.g., Bardeen-Cooper-Schrieffer pairing) encounter nonconvergence problem when applied sidebands are built on broken-pair excited intrinsic configurations. To overcome this...
The fission processes of thermal excited nuclei are conventionally studied by statistical models which rely on inputs phenomenological level densities and potential barriers. Therefore the microscopic descriptions spontaneous induced very desirable for a unified understanding various processes. We propose to study rates, at both low high temperatures, with microscopically calculated temperature-dependent barriers collective mass parameters. finite-temperature Skyrme-Hartree-Fock+BCS method....
The non-perturbative ab initio calculations of infinite nuclear matter using In-Medium Similarity Renormalization Group (IMSRG) method is developed in this work, which enables with chiral two and three-nucleon forces at N$^2$LO N$^3$LO. Results from the many-body perturbation theory different orders coupled-cluster are also presented for comparison. It shown that approaches lead to divergences a harder interaction pure neutron matter. For symmetric matter, such would appear even soft...
We employed the Skyrme-Hartree-Fock model to investigate density distributions and their dependence on nuclear shapes isospins in superheavy mass region. Different Skyrme forces were used for calculations with a special comparison experimental data $^{208}\mathrm{Pb}$. The ground-state deformations, radii, neutron-skin thicknesses \ensuremath{\alpha}-decay energies also calculated. Density discussed of single-particle wave functions shell fillings. Calculations show that deformations have...
Condensed Fermi systems with an odd number of particles can be described by means polarizing external fields having a time-odd character. We illustrate how this works for gases and atomic nuclei treated density-functional theory or Hartree-Fock-Bogoliubov theory. discuss the method based on introducing two chemical potentials different superfluid components, whereby one may change particle-number parity underlying quasiparticle vacuum. Formally, is variant noncollective cranking, procedure...
Based on the Hartree-Fock-Bogoliubov solutions in large deformed coordinate spaces, finite amplitude method for quasiparticle random-phase approximation (FAM-QRPA) has been implemented, providing a suitable approach to probing collective excitations of weakly bound nuclei embedded continuum. The monopole excitation modes magnesium isotopes up neutron drip line have studied with FAM-QRPA framework both coordinate-space and harmonic oscillator basis methods. Enhanced soft strengths...
We demonstrate that Bayesian machine learning can be used to treat the vast amount of experimental fission data which are noisy, incomplete, discrepant, and correlated. As an example, two-dimensional cumulative yields (CFY) neutron-induced $^{238}$U evaluated with energy dependencies uncertainty qualifications. For independent (IFY) very few data, heterogeneous fusion CFY IFY is employed interpolate dependence. This work shows facilitate further utilization imperfect raw nuclear data.
To explore the nature of collective modes in weakly bound nuclei, we have investigated deformation effects and surface flow patterns isovector dipole a shape-coexisting nucleus, $^{40}\mathrm{Mg}$. The calculations were done fully self-consistent continuum finite-amplitude quasiparticle random phase approximation large deformed spatial mesh. An unexpected result pygmy giant having disproportionate splittings strength functions was obtained. Furthermore, transition current densities...
The Bayesian machine learning is a promising tool for the evaluation of nuclear fission data but its potential capability has not been fully realized. We attempt to optimize performances multilayer neural networks evaluations yields. influences adjustments data, activation functions, network structures have studied. In particular, negative values net functions penalized avoid non-physical inferences Presently with double hidden layers optimal compared single-layer or deeper networks. These...