A lot of the info in this node is sorta correct but not really correct so i will attempt to make it more accurate. What i know of neutron stars i have learned from my time as an astro-physics major and while i still don't have the physics to understand a neutron star i am very familiar with the concepts.
First off there are many ways to form a neutron star not just supernova, although the supernova is the most common. When a star is in its latter stages of life it has a small core which is layered. The outer layer is burning
hydrogen, the
helium, then there is a jumbled of
oxygen neon and
carbon and others. Eventually the star stars to run out of the fuel in the center which is normally silicon. The
silicon fuses to make
iron which cannot be fused to make more energy. Iron is a dead end. The stars energy source is shut off. Now the core cools and contracts very fast. It takes about a tenth of a second. The energy release from this contraction
photodisintegrates much of the iron.
Neutronization then begins in the dense core forcing electrons into protons forming neutrons. Atoms break down into just balls of neutron. After about a quater of a second the core is solid
neutrons and can be contracted no more the layers that were moving downward as fast as 15% of the spped of light bounce off the now solid core. This bounce is the
shockwave which causes the supernova. As it travels throught the star it is like a tidl wave of almost infinite size and energy. This shockwave and the flood of
neutrinos from the
neutronization force the energy outward blowing off the less dense outer layers in a
supernova.
What we have left is a neutron star. This star will have to have a mass of more than 1.4 solar masses and less than 3 solar masses. (the upper limits of the neutron star's mas are uncertain due to uncertainties in the strength of the strong electric force.)
The neutron star has a radius of about 10-15 kilometers. The inner 10 meters radius is a superfluid and superconductive soup of protons and neutrons. on thsi floats a kilometer or so o superfluid neutrons and the top is a crust of neutrons. (This is the most up to date model. THis is an area of current research and there is uncertainty about the interior of a neutron star.)
Ok, i am done for now, anything else you want added to this /msg me. Enjoy :)