2017/11/22 by Wynn C. G. Ho, Nils Andersson, Vanessa Graber · 16 citations
Earth and Planetary Sciences · Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics #Condensed matter physics #Flux (metallurgy) #High-pressure geophysics and materials #Magnetic field #Magnetic flux #Materials science #Meissner effect #Neutron #Neutron star #Nuclear physics #Pairing #Physics #Proton #Pulsars and Gravitational Waves Research #Superconductivity #astro-ph.HE #cond-mat.supr-con #hep-ph #nucl-th
paper · pdf · open access · doi:10.1103/physrevc.96.065801
published in Physical Review C 96(6) (American Institute of Physics) · 6 pages, 5 figures; accepted for publication in Physical Review C
arxiv created 2017/11/22 · openalex publication_date 2017/12/04 · arxiv updated 2017/12/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
A superconductor of paired protons is thought to form in the core of neutron stars soon after their birth. Minimum energy conditions suggest magnetic flux is expelled from the superconducting region due to the Meissner effect, such that the neutron star core is largely devoid of magnetic fields for some nuclear equation of state and proton pairing models. We show via neutron star cooling simulations that the superconducting region expands faster than flux is expected to be expelled because cooling timescales are much shorter than timescales of magnetic field diffusion. Thus magnetic fields remain in the bulk of the neutron star core for at least 106--107\phantom\rule4.pt0exyr. We estimate the size of flux free regions at 107\phantom\rule4.pt0exyr to be \ensuremath\lesssim100\phantom\rule4.pt0exm for a magnetic field of 1011\phantom\rule4.pt0exG and possibly smaller for stronger field strengths. For proton pairing models that are narrow, magnetic flux may be completely expelled from a thin shell of approximately the above size after 105\phantom\rule4.pt0exyr. This shell may insulate lower conductivity outer layers, where magnetic fields can diffuse and decay faster, from fields maintained in the highly conducting deep core.