Can we mimic neutron stars?

[caliskan]

Hello,

One of my colleagues is asking if we can build layered structures to mimic neutron stars. What we know is that the surface of a neutron star can be treated like a structure formed by iron.

Thank you,
Serkan

[Petr Khomyakov]

What is a typical mass density of iron in an neutron star? It is likely to be so dense that nuclei are so close to each other that classical electrostatics might fail, requiring quantum electrodynamics corrections to the Coulomb law describing interaction between point charges assumed in all our calculations. I am not sure nuclei can be seen as point charges in neutron stars, maybe at the surface region.

Formally, one can indeed compress iron in atomistic, DFT calculations to any mass density, provided this does not cause numerical issues due to too close atoms.  Also, what do those layered structures look like? I would guess a material under that enormous pressure would show a phase transition to some peculiar phase. In principle, that can be studied, provided the governing equations of DFT still hold true, and no numerical issues are encountered for a given, high mass density.

[caliskan]

  Thank you for your response. A neutron star can be treated like a sphere consisting of inner core, outer core, inner crust and outer crust. We only concentrate on outer crust which can be divided into 3 layers in terms of density (d) of nuclei: (i) d < 10⁴ g/cm³, (ii) 10⁷>d > 10⁴ g/cm³, (iii) 10¹¹>d > 10⁷ g/cm³.
  When d ~10⁴ g/cm³ , atoms are fully ionized.   When d >=10⁷ g/cm³ , nuclei become neutron rich (due to electron capturing).  When d >=10¹¹ g/cm³ , neutrons become free.
   Thanks,
   Serkan