https://doi.org/10.1140/epjp/s13360-024-05399-2
Regular Article
Thermal properties of the spherical 
Ca nucleus
Department of Physics, Faculty of Science, Zarqa University, Al-Zarqa, Jordan
a moh2hassen@yahoo.com, mseileek@zu.edu.jo
Received:
26
March
2024
Accepted:
25
June
2024
Published online:
6
July
2024
Under different temperatures, the thermal properties of the Ca nucleus were studied. An effective Hamiltonian based on Ried soft core (RSC) and Nijmegen (Nijm.II) interactions used in mean-field calculations. The sensitivity of the thermal properties to the choice of nucleon–nucleon (NN) potential is examined. In particular, thermal response obtained with RSC and Nijmegen (Nijm.II) potentials are compared. A finite temperature framework constrained by the Hartree–Fock procedure is applied. Calculations were done in a non-core model space containing of 6 main oscillator shells (that is, twenty-one orbitals of a single particle). The sensibility of thermal properties like: entropy, binding energy, Helmholtz free energy, nuclear radius and single-particle spectrum are examined versus temperature. This work was conducted in the range of temperature from 0 to 8 MeV. When incrementing of temperature for the Ca nucleus is raised by 8 MeV, the excitation energy of 279.973 MeV appears to yield an 8.3% growth in the nucleus volume. In other words, the coefficient of volume for expansion increases with heating for nuclei. With increasing temperature, the specific heat of the nucleus decreases. It can be seen that there is an inverse ratio between Helmholtz free energy and heating. Also, there is a quadratic relationship between the radial expansion of nuclear volume and heating. For 
MeV, there is a linear relationship between entropy and heating. Over the range of temperature up to 8 MeV, the results for the Ca nucleus do not dramatically differ between our two choices of realistic N-N interaction. Subtle differences are observed which will be challenging to resolve experimentally. For further efforts, we can concentrate on obtaining extended results with the more recent N-N interaction. Finally, the thermal properties were not responsive at lower temperatures, and this behavior was attributed to the effects of the closure shell.
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© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2024. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
