DFMSPH22: A C-code for the double folding interaction potential of two spherical nuclei

Abstract

This is a new version of the DFMSPH (DFMSPH14, DFMSPH19) code published earlier. The new version is designed to obtain the nucleus–nucleus potential between two spherical nuclei using the double folding model (DFM). In particular, the code enables one to find the Coulomb barrier. Using the new version, one can employ three types of effective nucleon–nucleon interaction: the M3Y, Migdal, and relativistic mean-field interactions. The main functionalities of the original code (the nucleus–nucleus potential as a function of the distance between the centers of mass of colliding nuclei and the characteristics of the Coulomb barrier) are retained. The new version enables using proton or neutron as the projectile particle for all nucleon–nucleon interactions but the Migdal one. New version program summaryProgram title: DFMSPH22CPC Library link to program files:https://doi.org/10.17632/n6bsf4zxcz.3Code Ocean capsule:https://codeocean.com/capsule/1595275Licensing provisions: GLPv2Programming language: CJournal reference of previous version: Comput. Phys. Commun. 242 (2019) 153–155Does the new version supersede the previous version? YesReason for new version: Different versions of the relativistic mean-field effective NN-forces are used in the literature by different groups of researchers but seldom within the same numerical scheme; proton or neutron could not be used as the projectile nucleus in the previous version.Summary of revisions: Two extra options have been added in comparison with the previous version: •In the DFMSPH19 [1], the effective nucleon–nucleon (NN) M3Y and Migdal forces were used as the basis for the nucleus–nucleus interaction potential obtained by means of the double-folding model. In the new version, DFMSPH22, the user still has the same options, but there is an extra possibility to use one of the Relativistic Mean-Field (RMF) effective NN-forces. The nucleus–nucleus potential based on these forces is applied in the literature every now and again to evaluate the nucleus–nucleus potential energy (see, e.g. [2–5]). The corresponding equations and different parameter sets of the RMF forces implemented in DFMSPH22 are presented in the Supplementary material file. In this file, one finds also the comparison of the total potential as well as the nuclear part of it obtained using the RMF NN forces with those obtained using M3Y NN forces [1,6].•In the present version, we include a possibility for using proton or neutron as the projectile particle which was absent before. This option works for all the NN-forces but the Migdal one due to the structure of the latter. A restriction when using this option is that the density dependence does not work with proton or neutron as the projectile. See details in the Supplementary material file. The code consists now of 6 C-files and one header file. It reads the data from 5 input files and prints the results into 4 output files. The details of the changes in each source file as well as the description of the input and output files are presented in file <Program_changes.txt>. The input and output files corresponding to two test runs are included in the program files archive.Some misprints in Refs. [1, 6] are corrected (see the Supplementary material file).Nature of problem: The code calculates the bare (i.e. ignoring the channels coupling) interaction potential between two spherical colliding nuclei as a function of the center of mass distance in a semi-microscopic way. The height and radius, as well as the curvature and skewness of the Coulomb barrier, are evaluated. Dependence of these barrier parameters upon the type and/or characteristics of the effective NN forces (like e.g. M3Y, Migdal, or relativistic mean-field type; the range of the exchange part of the nuclear term) as well as upon the parameters of the density distributions can be studied.Solution method: The nucleus–nucleus potential is calculated using the double folding model with the Coulomb and effective NN interactions. For the direct parts of the Coulomb and nuclear terms, the Fourier transform method is used. For the exchange part most often the zero-range approximation is used. To calculate the exchange part of the nucleus–nucleus potential based on the M3Y interaction with the finite range, the density matrix expansion method is applied.Acknowledgment The authors are indebted to Dr. Wasiu Yahya for finding misprints in Refs. [6, 7].ReferencesI.I. Gontchar, M.V. Chushnyakova, N.A. Khmyrova, Comput. Phys. Commun. 242 (2019) 153–155.B. Singh, M. Bhuyan, S.K. Patra, R.K. Gupta, J. Phys. G Nucl. Part. Phys. 39 (2012) 025101.C. Lahiri, S.K. Biswal, S.K. Patra, Int. J. Mod. Phys. E 25 (2016) 1650015.M. Bhuyan, R. Kumar, Phys. Rev. C 98 (2018) 054610.M. V Chushnyakova, I.I. Gontchar, N.A. Khmyrova, J. Phys. G Nucl. Part. Phys. (2020) doi: 10.1088/1361-6471/ab907a.I.I. Gontchar, M.V. Chushnyakova, Comput. Phys. Commun. 181 (2010) 168–182.I.I. Gontchar, M.V. Chushnyakova, Comput. Phys. Commun. 206 (2016) 97–102.