Nuclear Dynamics with the Sky3D code

A description is presented of how to use the Sky3D time-dependent Hartree-Fock code to calculate giant monopole resonances. This requires modification to the code, and a step-by-step guide of how to make the necessary modification is given. An example of how to analyse the output of the code to obtain quantities of physics interest is included. Together, the modifications and the post-processing are intended to serve as a typical example of how the code, which was designed to be extendable to particular users' needs, can be extended.Comment: submitted to Proceedings of the International Workshop on Nuclear Theory 33 (Rila, Bulgaria

On the Stable Relative Orientation of Groups Connected by a Carbon-Carbon Single Bond

Langseth and his co-workers [1] have recently applied the results of essentially incomplete spectroscopic studies of liquid cyclohexane, symmetrical tetrachloroethane, and ethylene deuterobromide to a discussion of the intramolecular forces restricting internal rotation about the C-C bond. We believe that none of their structural conclusions is correct. Their discussion is based on their conclusion that in these molecules the opposed or eclipse configurations are the stable ones. Insofar as liquid cyclohexane and symmetrical tetrachloroethane are concerned this conclusion is most probably incorrect since it directly contradicts the results of a great number of more straightforward studies of these and similar molecules

Continuum time-dependent Hartree-Fock for giant resonances in spherical nuclei

This paper deals with the solution of the spherically symmetric time-dependent Hartree-Fock approximation applied in the case of nuclear giant monopole resonances. The problem is spatially unbounded as the resonance state is in the continuum. The practical requirement to perform the calculation in a finite-sized spatial region results in a difficulty with the spatial boundary conditions. Here we propose a absorbing boundary condition scheme to handle the conflict. The derivation, via a Laplace transform method, and implementation is described. The accuracy and efficiency of the scheme is tested and the results presented to support the case that they are a effective way of handling the artificial boundary.Comment: 13 pages, 8 figure

Low-Energy Heavy-Ion Reactions and the Skyrme Effective Interaction

The Skyrme effective interaction, with its multitude of parameterisations, along with its implemen- tation using the static and time-dependent density functional (TDHF) formalism have allowed for a range of microscopic calculations of low-energy heavy-ion collisions. These calculations allow variation of the effective interaction along with an interpretation of the results of this variation informed by a comparison to experimental data. Initial progress in implementing TDHF for heavy-ion collisions necessarily used many approximations in the geometry or the interaction. Over the last decade or so, the implementations have overcome all restrictions, and studies have begun to be made where details of the effective interaction are being probed. This review surveys these studies in low energy heavy-ion reactions, finding significant effects on observables from the form of the spin-orbit interaction, the use of the tensor force, and the inclusion of time-odd terms in the density functional.Comment: submitted to Prog. Part. Nucl. Phy

Shapes and Dynamics from the Time-Dependent Mean Field

Explaining observed properties in terms of underlying shape degrees of freedom is a well--established prism with which to understand atomic nuclei. Self--consistent mean--field models provide one tool to understand nuclear shapes, and their link to other nuclear properties and observables. We present examples of how the time--dependent extension of the mean--field approach can be used in particular to shed light on nuclear shape properties, particularly looking at the giant resonances built on deformed nuclear ground states, and at dynamics in highly-deformed fission isomers. Example calculations are shown of $^{28}$Si in the first case, and $^{240}$Pu in the latter case.Comment: 9 pages, 5 figures, to appear in proceedings of International Workshop "Shapes and Dynamics of Atomic Nuclei: Contemporary Aspects" (SDANCA-15), 8-10 October 2015, Sofia, Bulgari

Cause of the charge radius isotope shift at the \emph{N}=126 shell gap

We discuss the mechanism causing the `kink' in the charge radius isotope shift at the N=126 shell closure. The occupation of the 1$i_{11/2}$ neutron orbital is the decisive factor for reproducing the experimentally observed kink. We investigate whether this orbital is occupied or not by different Skyrme effective interactions as neutrons are added above the shell closure. Our results demonstrate that several factors can cause an appreciable occupation of the 1$i_{11/2}$ neutron orbital, including the magnitude of the spin-orbit field, and the isoscalar effective mass of the Skyrme interaction. The symmetry energy of the effective interaction has little influence upon its ability to reproduce the kink.Comment: 4 pages, 4 figures, to be submitted to proceedings of INPC 201