Titel:
Magnetic Fields in Superconducting Neutron Stars

Abstract:
Protons in dense nuclear matter are expected to be superconducting,
and recent observations of neutron star cooling support the idea that
the protons in neutron star cores form a superconductor, with gaps of
order 1 MeV.  Under typical circumstances, the proton
superconductor will be Type II, which means that magnetic flux is
confined to flux tubes.
This restriction has important effects on the structure of the
magnetic field of a neutron star, not only in the Type II core but also
in the normal conductor in its outer layers.
This linkage between the superconductor and normal conductor has observable 
implications.