A5048258384- Nuclear physics research studies
- Quantum Chromodynamics and Particle Interactions
- Atomic and Molecular Physics
- Astronomical and nuclear sciences
- Advanced NMR Techniques and Applications
- Nuclear Physics and Applications
- Advanced Chemical Physics Studies
- Quantum Computing Algorithms and Architecture
- Quantum, superfluid, helium dynamics
- Quantum chaos and dynamical systems
- High-pressure geophysics and materials
- Nuclear reactor physics and engineering
- Astro and Planetary Science
- Superconducting Materials and Applications
- Magnetic confinement fusion research
- Quantum Information and Cryptography
- Particle accelerators and beam dynamics
- Quantum many-body systems
- Pulsars and Gravitational Waves Research
- Fusion materials and technologies
- High-Energy Particle Collisions Research
- Radioactive Decay and Measurement Techniques
- Quantum Mechanics and Applications
- Rare-earth and actinide compounds
- Atomic and Subatomic Physics Research
University of Surrey
2015-2025
United Kingdom Atomic Energy Authority
2022-2024
Culham Science Centre
2005-2024
Cadi Ayyad University
2020
Guildford Hospital
2010-2015
Culham Centre for Fusion Energy
2005-2013
Faculty of 1000 (United Kingdom)
2011
Universidad Nacional Autónoma de México
2009
KTH Royal Institute of Technology
2008
AlbaNova
2008
This paper presents a detailed assessment of the ability 240 Skyrme interaction parameter sets in literature to satisfy series criteria derived from macroscopic properties nuclear matter vicinity saturation density at zero temperature and their dependence, by liquid-drop model, experiments with giant resonances heavy-ion collisions. The objective is identify those parametrizations which best current understanding physics over wide range applications. Out models, only 16 are shown all these...
The nuclear mean-field model based on Skyrme forces or related density functionals has found wide-spread application to the description of ground states, collective vibrational excitations, and heavy-ion collisions. code Sky3D solves static dynamic equations in a three-dimensional Cartesian mesh with isolated periodic boundary conditions no further symmetry assumptions. Pairing can be included BCS approximation. is implemented view allow easy modifications for including additional physics...
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.
An enhanced electric octupole (E3) strength of 45(5) W.u. has been measured for the <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msup><a:mrow><a:mn>3</a:mn></a:mrow><a:mrow><a:mo>−</a:mo></a:mrow></a:msup><a:mo stretchy="false">→</a:mo><a:msup><a:mrow><a:mn>0</a:mn></a:mrow><a:mrow><a:mo>+</a:mo></a:mrow></a:msup></a:mrow></a:math> transition in <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"...
The effective Skyrme interaction has been used extensively in mean-field models for several decades and many different parametrizations of the have proposed. All these give similar agreement with experimental observables nuclear ground states as well properties infinite symmetric matter at saturation density ${n}_{0}.$ However, when applied over a wider range densities (up to $\ensuremath{\sim}{3n}_{0})$ they predict widely varying behavior both asymmetric matter. A particularly relevant...
Background: Nuclear fission is a complex large-amplitude collective decay mode in heavy nuclei. Microscopic density functional studies of have previously concentrated on adiabatic approaches based constrained static calculations ignoring dynamical excitations the fissioning nucleus and daughter products.Purpose: We explore ability dynamic mean-field methods to describe fast processes beyond barrier, using nuclide $^{240}\text{Pu}$ as an example.Methods: Time-dependent Hartree-Fock Skyrme...
Lead-208 is the heaviest known doubly magic nucleus and its structure therefore of special interest. Despite this magicity, which acts to provide a strong restorative force toward sphericity, it exhibit both octupole correlations some strongest quadrupole collectivity observed in systems. In Letter, we employ state-of-the-art experimental equipment conclusively demonstrate, through four Coulomb-excitation measurements, presence large, negative, spectroscopic moment for vibrational <a:math...
Mean lifetime measurements of low-lying yrast positive- and negative-parity states <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mmultiscripts><a:mi>Gd</a:mi><a:mprescripts/><a:none/><a:mn>150</a:mn></a:mmultiscripts></a:math> have been performed with the ROSPHERE array using <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mrow><b:mmultiscripts><b:mi>Ce</b:mi><b:mprescripts/><b:none/><b:mn>140</b:mn></b:mmultiscripts><b:mo>(</b:mo><b:mmultiscripts><b:mi...
The spectral distribution of isovector dipole strength is computed using the time-dependent Skyrme-Hartree-Fock method with subsequent analysis. calculations are done without any imposed symmetry restriction, allowing nuclear shape to be dealt with. scheme used study deformation dependence giant resonances and its interplay Landau fragmentation (owing 1ph states). Results shown for chain Nd isotopes, superdeformed $^{152}\mathrm{Dy}$, triaxial $^{188}\mathrm{Os}$, $^{238}\mathrm{U}$.
Absorbing boundary conditions are often employed in time-dependent mean-field calculations to cope with the problem of emitted particles which would otherwise return back onto system and falsify dynamical evolution. We scrutinize two widely used methods, imaginary potentials gradual attenuation by a mask function. To that end, we consider breathing oscillations $^{16}\mathrm{O}$ nucleus computed on radial one-dimensional grid coordinate space. The most critical test case is computation...
The energies of the canonical (standard, amino-keto) and tautomeric (non-standard, imino-enol) charge-neutral forms adenine-thymine base pair (A-T A*-T*, respectively) are calculated using density functional theory. reaction pathway is then computed a transition state search to provide asymmetric double-well potential minima along with barrier height shape, which combined create energy surface polynomial fit. influence quantum tunnelling on proton transfer within H-bond (modelled as DFT...
Background: Nuclear fission is a complex large-amplitude collective decay mode in heavy nuclei. Microscopic density functional studies of have previously concentrated on adiabatic approaches based constrained static calculations ignoring dynamical excitations the fissioning nucleus and daughter products.Purpose: We explore ability dynamic mean-field methods to describe induced processes, using quadrupole boosts nuclide $^{240}\mathrm{Pu}$ as an example.Methods: Following upon work presented...
Energy dependence of fission observables is a key issue for wide nuclear applications. We studied real-time dynamics from low-energy to high excitations in the compound nucleus $^{240}\mathrm{Pu}$ with time-dependent Hartree-Fock $+$ BCS approach. It shown that evolution time later phase towards scission considerably lengthened at finite temperature. As role dynamical pairing vanishing excitations, random transition between single-particle levels around Fermi surface mimic thermal...
The Sky3D code has been widely used to describe nuclear ground states, collective vibrational excitations, and heavy-ion collisions. approach is based on Skyrme forces or related energy density functionals. static dynamic equations are solved a three-dimensional grid, pairing implemented in the BCS approximation. This updated version of aims facilitate calculation strength functions regime linear response theory, while retaining all existing functionality use cases. benchmarked against...
We investigate the role of odd-odd (with respect to time inversion) couplings in Skyrme force on collisions light nuclei, employing a fully three-dimensional numerical treatment without any symmetry restrictions and with modern functionals. demonstrate necessity these suppress spurious spin excitations owing spin-orbit free translational motion nucleus but show that collision situation there is strong excitation even spin-saturated systems which persists departing fragments. The energy loss...
The nuclear time-dependent Hartree-Fock model formulated in the three-dimensional space,based on full Skyrme energy density functional and complemented with tensor force,is presented for first time. Full self-consistency is achieved by model. application to isovector giant dipole resonance discussed linear limit, ranging from spherical nuclei (16O, 120Sn) systems displaying axial or triaxial deformation (24Mg, 28Si, 178Os, 190W, 238U). Particular attention paid spin-dependent terms central...
We revisit the problem of kink in charge radius shift neutron-rich even isotopes near N=126 shell closure. show that ability a Skyrme force to reproduce isotope is determined by occupation neutron 1i(11/2) orbital beyond and corresponding change it causes deeply-bound protons orbitals with principal quantum number 1. Given observed position single-particle energies, one must either ensure allowed through correlations, or not demand energies agree experimental values at mean-field level.
Collinear laser spectroscopy experiments with the Sc + transition 3d4s 3 D 2 → 3d4p F at λ = 363.1 nm were performed on 42-46 isotopic chain using an ion guide isotope separator a cooler-buncher.Nuclear magnetic dipole and electric quadrupole moments as well shifts determined from hyperfine structure for five ground states two isomers.Extensive multiconfigurational Dirac-Fock calculations in order to evaluate specific mass-shift, M SMS , field-shift, F, parameters which allowed evaluation of...
Structural evolution in neutron-rich Os and W isotopes is investigated terms of the interacting boson model (IBM) Hamiltonian determined by (constrained) Hartree-Fock-Bogoliubov calculations with Gogny-D1S energy density functional (EDF). The interaction strengths IBM are produced mapping potential surface (PES) Gogny-EDF quadrupole degrees freedom onto corresponding PES system. We examine prolate-to-oblate shape/phase transition which predicted to take place this region as a function...
The dipole response of ${}_{34}^{76}$Se in the energy range from 4 to 9 MeV has been analyzed using a $(\stackrel{P\vec}{\ensuremath{\gamma}},{\ensuremath{\gamma}}^{\ensuremath{'}})$ polarized photon scattering technique, performed at High Intensity $\ensuremath{\gamma}$-Ray Source facility Triangle Universities Nuclear Laboratory, complement previous work unpolarized photons. results this offer both an enhanced sensitivity scan and unambiguous determination parities observed $J=1$ states....
The Skyrme effective interaction, with its multitude of parameterisations, along implemen- tation using the static and time-dependent density functional (TDHF) formalism have allowed for a range microscopic calculations low-energy heavy-ion collisions. These allow variation interaction an interpretation results this informed by comparison to experimental data. Initial progress in implementing TDHF collisions necessarily used many approximations geometry or interaction. Over last decade so,...
Background: It is generally acknowledged that the time-dependent Hartree--Fock (TDHF) method provides a useful foundation for fully microscopic many-body theory of low-energy heavy ion reactions. The TDHF also known in nuclear physics small-amplitude domain, where it description collective states, and based on mean-field formalism, which has been relatively successful approximation to problem. Currently, being widely used study fusion excitation functions, fission, deep-inelastic scattering...