Microscopic Calculations for Fusion Reactions in the Neutron Star Crust

Strategic Insights -

Research has unveiled new findings on physics, specifically focusing on the interaction potentials, cross sections, and S-factors for fusion reactions involving stable and neutron-rich isotopes of C, O, Ne, Mg, and Si in the neutron star crust. The study employed a microscopic relativistic energy density functional based on the Dirac-Brueckner-Hartree-Fock (DBHF) approach for asymmetric nuclear matter. The calculations were used to predict fusion hindrance, which is the phenomenon where the fusion cross section decreases at subbarrier energies. The results show that the DBHF potentials are able to describe hindrance for medium-heavy systems, and that the M3Y and SP potentials are unable to do so due to producing extremely deep potentials in the overlap region.

Key Takeaways:

  • The DBHF approach was used to calculate interaction potentials, cross sections, and S-factors for fusion reactions involving stable and neutron-rich isotopes of C, O, Ne, Mg, and Si in the neutron star crust.
  • The calculations were performed at subbarrier energies using a microscopic relativistic energy density functional based on the Dirac-Brueckner-Hartree-Fock (DBHF) approach for asymmetric nuclear matter.
  • The DBHF potentials were found to be in excellent agreement with experimental data for the systems 16O + 16,18O,12C + 16,18O, and 28Si + 28,30Si.
  • Hindrance was naturally predicted by the DBHF potentials for medium-heavy systems, such as Ne + Ne, Ne + Mg, and Si + Si.
  • CC calculations significantly enhanced the cross section at subbarrier energies and predicted measurable shifts in the onset energy of hindrance.
  • The influence of neutron excess on fusion hindrance was investigated for the neutron-rich systems, 28Si + 30-40Si and 40Si + 40Si, and an interesting correlation between them was found.
  • The impact of the equation of state on fusion reactions was investigated, finding significant sensitivity to the symmetry energy and incompressibility of nuclear matter.
  • The DBHF approach was demonstrated as a powerful model for a unified description of nuclear matter, nuclear reactions, and astrophysical environments.

Statistics:

  • The study involved the calculation of interaction potentials, cross sections, and S-factors for fusion reactions involving stable and neutron-rich isotopes of C, O, Ne, Mg, and Si in the neutron star crust.
  • The calculations were performed at subbarrier energies using a microscopic relativistic energy density functional based on the Dirac-Brueckner-Hartree-Fock (DBHF) approach for asymmetric nuclear matter.
  • The DBHF potentials were found to be in excellent agreement with experimental data for the systems 16O + 16,18O,12C + 16,18O, and 28Si + 28,30Si.
  • The hindrance phenomenon was predicted for medium-heavy systems, such as Ne + Ne, Ne + Mg, and Si + Si, with the DBHF potentials.
  • The CC calculations enhanced the cross section at subbarrier energies and predicted measurable shifts in the onset energy of hindrance for the systems 16O + 16,18O,12C + 16,18O, and 28Si + 28,30Si.

Sources:

  • Microscopic Calculations for Fusion Reactions Involving Stable and Neutron-rich Isotopes of C, O, Ne, Mg, and Si In the Neutron Star Crust (Physical Review C, 2025;112(3)).
  • NewsRx. New Data from Atomic Energy Authority Illuminate Findings in Physics (Microscopic Calculations for Fusion Reactions Involving Stable and Neutron-rich Isotopes of C, O, Ne, Mg, and Si In the Neutron Star Crust). Journal of Physics Research. October 21, 2025; p 1895.
  • Atomic Energy Authority, Department of Mathematics and Theoretical Physics, Cairo, Egypt.