Magnetic diffusion and the motion of field lines

A. L. Wilmot-Smith, E. R. Priest, G. Hornig

    Research output: Contribution to journalArticle

    12 Citations (Scopus)

    Abstract

    Diffusion of a magnetic field through a plasma is discussed in one-, two- and three-dimensional configurations, together with the possibility of describing such diffusion in terms of a magnetic flux velocity, which, when it exists, is in general non-unique. Physically useful definitions of such a velocity include doing so in terms of the energy flow or in such a way that it vanishes in a steady state. Straight field lines (or plane flux surfaces) diffuse as if flux is disappearing at a neutral sheet, whereas circular field lines (or cylindrical flux surfaces) do so as if flux is disappearing at an 0-type neutral line. In three dimensions it is not always possible to define a flux velocity, for example when the magnetic flux through a closed field line is changing in time. However, in at least some such cases it is possible to describe the behaviour of the magnetic field in terms of a pair of quasi-flux-velocities.
    Original languageEnglish
    Pages (from-to)177-197
    Number of pages21
    JournalGeophysical & Astrophysical Fluid Dynamics
    Volume99
    Issue number2
    DOIs
    Publication statusPublished - 2005

    Fingerprint

    magnetic diffusion
    Fluxes
    surface flux
    Magnetic flux
    magnetic field
    magnetic flux
    energy flow
    Magnetic fields
    neutral sheets
    plasma
    magnetic fields
    Plasmas
    configurations

    Keywords

    • Magnetohydrodynamics (MHD)
    • Magnetic diffusion
    • Plasmas
    • MHD

    Cite this

    Wilmot-Smith, A. L. ; Priest, E. R. ; Hornig, G. / Magnetic diffusion and the motion of field lines. In: Geophysical & Astrophysical Fluid Dynamics. 2005 ; Vol. 99, No. 2. pp. 177-197.
    @article{57bb9b47dbe74f98a4ad0cbaeb56180c,
    title = "Magnetic diffusion and the motion of field lines",
    abstract = "Diffusion of a magnetic field through a plasma is discussed in one-, two- and three-dimensional configurations, together with the possibility of describing such diffusion in terms of a magnetic flux velocity, which, when it exists, is in general non-unique. Physically useful definitions of such a velocity include doing so in terms of the energy flow or in such a way that it vanishes in a steady state. Straight field lines (or plane flux surfaces) diffuse as if flux is disappearing at a neutral sheet, whereas circular field lines (or cylindrical flux surfaces) do so as if flux is disappearing at an 0-type neutral line. In three dimensions it is not always possible to define a flux velocity, for example when the magnetic flux through a closed field line is changing in time. However, in at least some such cases it is possible to describe the behaviour of the magnetic field in terms of a pair of quasi-flux-velocities.",
    keywords = "Magnetohydrodynamics (MHD), Magnetic diffusion, Plasmas, MHD",
    author = "Wilmot-Smith, {A. L.} and Priest, {E. R.} and G. Hornig",
    note = "dc.publisher: Taylor & Francis",
    year = "2005",
    doi = "10.1080/03091920500044808",
    language = "English",
    volume = "99",
    pages = "177--197",
    journal = "Geophysical & Astrophysical Fluid Dynamics",
    issn = "0309-1929",
    publisher = "Taylor & Francis",
    number = "2",

    }

    Magnetic diffusion and the motion of field lines. / Wilmot-Smith, A. L.; Priest, E. R.; Hornig, G.

    In: Geophysical & Astrophysical Fluid Dynamics, Vol. 99, No. 2, 2005, p. 177-197.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Magnetic diffusion and the motion of field lines

    AU - Wilmot-Smith, A. L.

    AU - Priest, E. R.

    AU - Hornig, G.

    N1 - dc.publisher: Taylor & Francis

    PY - 2005

    Y1 - 2005

    N2 - Diffusion of a magnetic field through a plasma is discussed in one-, two- and three-dimensional configurations, together with the possibility of describing such diffusion in terms of a magnetic flux velocity, which, when it exists, is in general non-unique. Physically useful definitions of such a velocity include doing so in terms of the energy flow or in such a way that it vanishes in a steady state. Straight field lines (or plane flux surfaces) diffuse as if flux is disappearing at a neutral sheet, whereas circular field lines (or cylindrical flux surfaces) do so as if flux is disappearing at an 0-type neutral line. In three dimensions it is not always possible to define a flux velocity, for example when the magnetic flux through a closed field line is changing in time. However, in at least some such cases it is possible to describe the behaviour of the magnetic field in terms of a pair of quasi-flux-velocities.

    AB - Diffusion of a magnetic field through a plasma is discussed in one-, two- and three-dimensional configurations, together with the possibility of describing such diffusion in terms of a magnetic flux velocity, which, when it exists, is in general non-unique. Physically useful definitions of such a velocity include doing so in terms of the energy flow or in such a way that it vanishes in a steady state. Straight field lines (or plane flux surfaces) diffuse as if flux is disappearing at a neutral sheet, whereas circular field lines (or cylindrical flux surfaces) do so as if flux is disappearing at an 0-type neutral line. In three dimensions it is not always possible to define a flux velocity, for example when the magnetic flux through a closed field line is changing in time. However, in at least some such cases it is possible to describe the behaviour of the magnetic field in terms of a pair of quasi-flux-velocities.

    KW - Magnetohydrodynamics (MHD)

    KW - Magnetic diffusion

    KW - Plasmas

    KW - MHD

    U2 - 10.1080/03091920500044808

    DO - 10.1080/03091920500044808

    M3 - Article

    VL - 99

    SP - 177

    EP - 197

    JO - Geophysical & Astrophysical Fluid Dynamics

    JF - Geophysical & Astrophysical Fluid Dynamics

    SN - 0309-1929

    IS - 2

    ER -