OHMIC DECAY OF MAGNETIC-FLUX EXPELLED FROM NEUTRON-STAR INTERIORS

We study Ohmic diffusion of magnetic flux expelled from the supercondu cting core of a neutron star to its crust owing to spindown-induced fi eld evolution. We rind that Ohmic decay time-scales in the range 10(7. 5)-10(9) yr obtain for a wide range of crustal temperatures and impuri ty concentrations for various equation of state models of neutron star matter. This result is in agreement with the Ohmic time-scale that ap pears to be required to explain observed magnetic field strengths of i solated and binary neutron stars in the spindown-induced magnetic flux expulsion scenario.