KEWPIE2: A cascade code for the study of dynamical decay of excited nuclei

Abstract

KEWPIE–a cascade code devoted to investigating the dynamical decay of excited nuclei, specially designed for treating very low probability events related to the synthesis of super-heavy nuclei formed in fusion–evaporation reactions–has been improved and rewritten in C++ programming language to become KEWPIE2. The current version of the code comprises various nuclear models concerning the light-particle emission, fission process and statistical properties of excited nuclei. General features of the code, such as the numerical scheme and the main physical ingredients, are described in detail. Some typical calculations having been performed in the present paper clearly show that theoretical predictions are generally in accordance with experimental data. Furthermore, since the values of some input parameters cannot be determined neither theoretically nor experimentally, a sensibility analysis is presented. To this end, we systematically investigate the effects of using different parameter values and reaction models on the final results. As expected, in the case of heavy nuclei, the fission process has the most crucial role to play in theoretical predictions. This work would be essential for numerical modeling of fusion–evaporation reactions. Program summaryProgram title: KEWPIE2Catalogue identifier: AEZB_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEZB_v1_0.htmlProgram obtainable from: CPC Program Library, Queen’s University, Belfast, N. IrelandLicensing provisions: GNU General Public License, version 3No. of lines in distributed program, including test data, etc.: 41230No. of bytes in distributed program, including test data, etc.: 259652Distribution format: tar.gzProgramming language: C++.Computer: All Linux based workstations, Apple machines.Operating system: Linux, OS X.RAM: Depending on the size of system and calculated quantities.Classification: 17.8, 17.10, 17.23.External routines: The latest version of the GSL library, available on http://www.gnu.org/software/gsl/Nature of problem: Estimating evaporation-residue cross-sections and average fission times related to the synthesis of super-heavy elements.Solution method: A specific algorithm based on the Bateman equations and the spectral discretization method.Restrictions: The main area of application is the study of the de-excitation of heavy or super-heavy nuclei.Running time: A few seconds up to several hours, depending on the calculated quantities (evaporation-residue cross-section or average fission time).