Isospin Dependence of Proton and Neutron Radii within Relativistic Mean Field Theory

The binding energies, shapes and sizes of even-even beta-stable nuclei with A >= 40 and a few chains of isotopes with Z=50, 56, 82, 94 protons and isotones with N=50, 82, 126 neutrons are analyzed. The average isospin dependence of the radii of protons and neutrons evaluated within the relativistic mean field theory is studied. A simple, phenomenological formula for neutron radii is proposed.Comment: 10 pages in Latex and 14 figures in the eps forma

Simple Formula for Nuclear Charge Radius

A new formula for the nuclear charge radius is proposed, dependent on the mass number (A) and neutron excess (N-Z) in the nucleus. It is simple and it reproduces all the experimentally available mean square radii and their isotopic shifts of even--even nuclei much better than other frequently used relations.Comment: The paper contains 7 pages in LateX and 6 figures (available upon request) in postscript. Email: [email protected]

Role of the shell and pairing effects in nuclear fission

The description of spontaneous fission of actinides by the macroscopic-microscopic method consisting of the Lublin Strasbourg Drop model and the two deformed Nilsson wells or the Yukawa folded single-particle potential is presented. The microscopic shell corrections are obtained by the Strutinsky method, while the pairing correlations are taken into account within the BCS theory. It was shown that the pairing strength should grow with increasing deformation of fissioning nucleus in order to obtain right estimates of the pairing field in the fission fragments. The fission barrier heights are estimated using the topographical theorem of Swiatecki

Interaction Strengths for the Fock-Space Formulation of the Nuclear Pairing Problem

A realistic nuclear mean-field hamiltonian with pairing has been diagonalized using Fock space representation that allows for nearly exact treatment of the problem. Calculations were performed for all the even-even nuclei with Z in (20, 100), whose pairing gaps were possible to extract out of the experimental masses. The optimal values of the pairing strength constants for the protons and neutrons have been found.Comment: Seminar given at XXXVII School of Physics in Zakopane, Poland. Paper in LaTeX, 4 pages including one figure, submitted to Acta Physica Polonica

On Microscopic Energy Corrections Around Scission Configuration

AbstractThe spontaneous fission of actinides is analysed by the macroscopic - microscopic method based on the Lublin Strasbourg Drop model and the two deformed Nilsson wells or Yukawa folded single particle potentials. The microscopic corrections are obtained within the Strutinsky prescription and the BCS theory. In the scission point the shell correction possess the additive property but this is not true for pairing correlations during asymmetric fission. Here the shape dependent pairing force of the δ or Gogny type should be used and the pairing strength should grow with increasing deformation of fissioning nucleus. The examples of sponta- neous fission results are presented. The possibility of β decay accompanying the spontaneous fission is noticed