#Fission uranium isotope generator#

It has been recently shown that some Gogny finite-range interactions suffer from finite-size instabilities in coordinate-space calculations. Analysis of the potential-energy surface in two dimensions is often very successful but it must be carried out with special attention to possible discontinuities. These issues may be partially solved by the analysis of the potential-energy surface spanned by triple constraints, but even in this case one may find multiple solutions and surface discontinuities. We analyze apparent problems that can be encountered in this type of calculations: multiple solutions for given constraints and transitions between various overlapping potential-energy surfaces. We have shown the existence of complicated structures on the energy surface that cannot be fully described in two-dimensional calculations. Two heavy isotopes representing different spontaneous fission modes, Cf252 (asymmetric) and No258 (bimodal), have been chosen for the analysis. We present a detailed analysis of fission barriers in the self-consistent Hartree-Fock-Bogoliubov approach with the D1S parametrization of the Gogny nucleon-nucleon interaction. A reasonable choice of constraints on multipole moments should be made to describe the topography of the surface completely within a reasonable amount of computing time. Microscopic studies of nuclear fission require the evaluation of the potential-energy surface as a function of the collective coordinates. The results of the calculations point towards dynamically enhanced octupole correlations around the ‘octupole magic’ neutron numbers N = 56 and N = 88. The coupling between the quadrupole and octupole degrees of freedom is found to be rather weak in all the considered nuclei and therefore the properties of the negative parity states can be reasonably well described in terms of the octupole degree of freedom alone.

Related quantities like reduced electromagnetic transition probabilities B ( E 1) and B ( E 3) and negative-parity excitation energies and their behavior with neutron number are discussed and compared with the available experimental data.

#Fission uranium isotope generator#

Starting with a set of Hartree–Fock–Bogoliubov constrained states we consider dynamic fluctuations of the collective variables by using the generator coordinate method. Mean field based methods including pairing are used in our microscopic description along with the Gogny D1M force. The impact of quadrupole and octupole collectivity in the dynamic of low-lying collective states is discussed for a set of Xe, Ba, Ce and Nd isotopes with neutron numbers 54 ⩽ N ⩽ 96. Complex discontinuities occurring in multiple coordinates may require alternative approaches which better utilise prior knowledge of the potential energy surface to narrow their searches. Conclusions: The smoothing methods presented in this work are resource-efficient and successful for simple discontinuities, and will improve the fidelity of potential energy surfaces as well as their subsequent uses in beyond mean-field applications. The effectiveness of each case is analysed both qualitatively and quantitatively. The most recent parametrizations D1S, D1N and D1M of the Gogny energy densityįunctional are used to describe fission in the isotopes $^$.