Slide 21 of 59
Notes:
The diagram shows a segment (ie a slice) through a neutron star. The core extends out to about 1km and has a density of 1e18 kg/m^3. Its substance is not well known however, - it could be a neutron solid, quark matter or a pion concentrate. It may not even exist.
2. From 1km out to 9km, there is a ‘neutron fluid’, a superfluid made up of neutrons and superconducting protons and electrons. The density in this region is between 2e17 and 1e18 kg/m^3.
1. In the inner crust, there is a lattice of neutron-rich nuclei with free degenerate neutrons and a degenerate relativistic electron gas. The neutron fluid pressure increases as the density increases.
The outer crust is solid and its matter is similar to that found in white dwarfs, ie heavy nuclei (mostly Fe) forming a Coulomb lattice embedded in a relativistic degenerate gas of electrons.
The density falls away relatively quickly in this region, down to a billion kg/m^3 in the outer crust.
On the very surface of the neutron star, densities dall below a billion kg/m^3 and matter consists of atomic polymers of 56Fe in the form of a close packed solid. The atoms become cylindrical, due to the effects of the strong magnetic fields. Stresses and fractures in the crust cause the glitches in the pulse period.
