Nuclear Mean Fields through Selfconsistent Semiclassical Calculations

Semiclassical expansions derived in the framework of the Extended Thomas-Fermi approach for the kinetic energy density tau(r) and the spin-orbit density J(r) as functions of the local density rho(r) are used to determine the central nuclear potentials V_n(r) and V_p(r) of the neutron and proton distribution for effective interactions of the Skyrme type. We demonstrate that the convergence of the resulting semiclassical expansions for these potentials is fast and that they reproduce quite accurately the corresponding Hartree-Fock average fields.Comment: LATEX, 25 pages, including 11 eps figures. to be published in Europ. Phys. Journal

Mean-Field Description of Fusion Barriers with Skyrme's Interaction

Fusion barriers are determined in the framework of the Skyrme energy-density functional together with the semi-classical approach known as the Extended Thomas-Fermi method. The barriers obtained in this way with the Skyrme interaction SkM* turn out to be close to those generated by phenomenological models like those using the proximity potentials. It is also shown that the location and the structure of the fusion barrier in the vicinity of its maximum and beyond can be quite accurately described by a simple analytical form depending only on the masses and the relative isospin of target and projectile nucleus.Comment: 7 pages, latex, 5 figure

Fission-Fragment Mass Distribution and Particle Evaporation at low Energies

Fusion-fission dynamics is investigated with a special emphasis on fusion reactions at low energy for which shell effects and pairing correlations can play a crucial role leading in particular to multi-modal fission. To follow the dynamical evolution of an excited and rotating nucleus we solve a 2-dimensional Langevin equation taking explicitly light-particle evaporation into account. The confrontation theory-experiment is demonstrated to give interesting information on the model presented, its qualities as well as its shortcomings.Comment: 19 pages, latex, 24 eps-figure

1.6 GHz VLBI Observations of SN 1979C: almost-free expansion

We report on 1.6 GHz Very-Long-Baseline-Interferometry (VLBI) observations of supernova SN 1979C made on 18 November 2002. We derive a model-dependent supernova size. We also present a reanalysis of VLBI observations made by us on June 1999 and by other authors on February 2005. We conclude that, contrary to our earlier claim of strong deceleration in the expansion, SN 1979C has been undergoing almost-free expansion ($m = 0.91\pm0.09$; $R \propto t^m$) for over 25 years.Comment: 4 pages, 4 figures; submitted to A&A on 14 May 2009. Accepted on 7 Jul 200

From Silence to Voice: A collaborative international partnership to develop a digital resource for use in clinical and education settings about sexual violence from perspectives of students, educators and survivors.

Gender based violence (GBV) – which includes sexual violence - is a significant global public health and societal problem, recognised as a global human rights issue by the World Health Organisation (WHO, 2017). Global estimates indicate that 1 in 3 women experience physical/sexual violence in their lifetime (WHO, 2017). GBV/SV exerts a detrimental impact not only on the lives and health of women, but also those who witness abuse and has been identified as a large scale problem in South Africa with recorded estimates that a woman is raped every seventeen seconds. The impact of GBV/SV on the physical and psychological wellbeing of those who experience abuse is wide ranging. It includes the immediate physical effects for example, physical injury as well as longer term chronic ill health as a result, acute and enduring psychological trauma, mental ill-health, alongside secondary physiological health issues such as gynaecological and sexual health (Feder et al. 2011). It is well evidenced however that healthcare professionals across the spectrum do not respond effectively often due to a lack of knowledge or professional confidence and their own values and assumptions surrounding GBV/SV (McGarry et al. 2015). Education is pivotal, and a proven means to tackle a growing global problem. This includes pre-qualifying healthcare students who are often not exposed to education about GBV/SV within their current curricula. Working with our project partners and key stakeholders in South Africa during 2019, including women who have experienced GBV/SV, the aim of this research was to engage stakeholders in the co-production of a digital e-learning resource to use across multiple healthcare disciplines on GBV/SV. Our aim is to describe the process of an international collaboration, provide the context using survey data and present the digital resource and the evaluations conducted on the application and use within education and clinical settings. References: Feder G, Davies R, Baird K, Dunne D, Eldridge S, Griffiths C, Gregory A, Howell A, Johnson, M., Ramsay J, Garcia-Moreno, C., Armin, A. (2016) The sustainable development goals, violence and women’s and children’s health (WHO) http://www.who.int/bulletin/volumes/94/5/16-172205/en/ (accessed 7.7.18) McGarry J., Baker C., Wilson C., Felton A., Banerjee A, (2015). Preparation for safeguarding in UK pre-registration graduate nurse education. Journal of Adult Protection. 17(6), 371-379 World Health Organisation (2017) Violence against women http://www.who.int/news-room/fact-sheets/detail/violence-against-women (accessed 7.7.18

Light-particle emission from the fissioning nuclei 126Ba, 188Pt and (266,272,278)/110: theoretical predictions and experimental results

We present a comparison of our model treating fission dynamics in conjunction with light-particle (n, p, alpha) evaporation with the available experimental data for the nuclei 126Ba, 188Pt and three isotopes of the element Z=110. The dynamics of the symmetric fission process is described through the solution of a classical Langevin equation for a single collective variable characterizing the nuclear deformation along the fission path. A microscopic approach is used to evaluate the emission rates for pre-fission light particles. Entrance-channel effects are taken into account by generating an initial spin distribution of the compound nucleus formed by the fusion of two deformed nuclei with different relative orientations

Evaporation of light particles from a hot, deformed and rotating nucleus

The dependence of the transmission coefficient on the deformation, the collective rotation and excitation energy of the compound nucleus emitting light particles is introduced in the framework of Wei{\ss}kopf's evaporation theory. The competition between fission and particle evaporation is treated by a~Langevin equation for the fission variable coupled to the emission process. Detailed calculations are presented on the decay of different Gd and Yb isotopes at an excitation energy of about 250~MeV. These calculations demonstrate the importance of the effects of nuclear deformation and of the initial spin distribution on the evaporation.Comment: 22 pages in LaTeX and 26 PS-figures include