aligned magnetic field
meydân-e meqnâtisi-ye âxatidé
Fr.: champ magnétique aligné
A magnetic field whose lines of force are oriented along a particular direction or by a particular manner (axially, vertically; randomly, properly, etc.)
azimuthal magnetic field
meydân-e meqnâtisi-ye sugâni
Fr.: champ magnétiquue azimutal
In the → solar dynamo model, a magnetic field that points from east to west or vice-versa.
Fr.: champ électromagnétique
A region of space consisting of coupled electric and magnetic lines of force at each point, generated by time-varying currents and accelerated charges.
force-free magnetic field
Fr.: champ magnétique sans force
The condition in a plasma when the → Lorentz force is zero, that is when the electric current flows along the magnetic field. Force-free magnetic fields are encountered in astrophysical plasmas with negligible gas pressure. The solar corona is the best available example of such fields in action in a plasma.
fossil magnetic field
meydân-e meqnâtisi-ye sangvâré, ~ ~ sangvâre-yi
Fr.: champ magnétique fossile
In a physical system, the → magnetic field belonging to an earlier magnetic process or event. A fossil magnetic field may be a vanished one or exist in relic forms. As an example, the solar magnetic field, which was present during the formation of the Sun, has disappeared over the last 4.6 billions years.
frozen magnetic field line
xatt-e meydân-e meqnâtisi-ye yax basté, ~ ~ ~ rocidé
Fr.: ligne de champ magnétique gelée
meydân-e zamin-meqnâtisi, ~ zamin-meqnâti
Fr.: champ géomagnétique
The magnetic field that is generated within the Earth and extends out around the Earth. The intensity of the magnetic field at the Earth's surface is about 0.32 → gauss at the equator and 0.62 gauss at the north pole.
interplanetary magnetic field
meydân-e meqnâtisi-ye andarsayyârei
Fr.: champ magnétique interstellaire
The magnetic field that is carried along with the solar wind and fills the solar system space. It is wound into a spiral structure by the rotation of the Sun. At the Earth's distance from the Sun, it has a strength of about 5 x 10-5 gauss.
interstellar magnetic field
meydân-e meqnâtisi-ye andaraxtari
Fr.: champ magnétique interstellaire
A large-scale, weak magnetic field, with an estimated strength of about 1 to 5 microgauss, that pervades the disk of the Milky Way Galaxy and controls the alignment of interstellar dust grains.
meydân-e meqnâtisi (#)
Fr.: champ magnétique
A field of force that is generated by electric currents, or, equivalently, a region in which magnetic forces can be observed.
magnetic field line
xatt-e meydân-e meqnâtisi (#)
Fr.: ligne de champ magnétique
An imaginary line used for representing the strength and direction of a magnetic field. Charged particles move freely along magnetic field lines, but are inhibited by the magnetic force from moving across field lines.
magnetic field strength
zur-e meydân-e meqnâtisi
Fr.: intensité du champs magnétique
Same as → magnetic intensity.
meridional magnetic field
meydân-e meqnâtisi-ye nimruzâni
Fr.: champ magnétiquue méridien
In the → solar dynamo model, a magnetic field that points from the north to south or south to north.
open magnetic field line
xatt-e bâz-e meydân-e meqnâtisi-ye
Fr.: ligne ouverte de champ magnétique
In the context of solar physics, a → magnetic field line when it crosses the solar surface only once, i.e., when it goes from surface to infinity. This is the case at a sufficiently large scale in → coronal holes. This is mostly not the case in → active regions.
poloidal magnetic field
meydân-e meqnâtisi-ye qotbivâr
Fr.: champ magnétique poloïdal
1) In → protoplanetary disk models, the magnetic field
whose large-scale lines of force depart away from the → accretion disk,
in the direction of the rotation axis.
solar magnetic field
meydân-e meqnâtisi-ye xoršid (#)
Fr.: champ magnétique solaire
The Sun's magnetic field which is probably created by the → differential rotation of the Sun together with the movement of charged particles in the → convective zone. Understanding how the solar magnetic field comes about is the fundamental problem of Solar Physics. The solar magnetic field is responsible for all solar magnetic phenomena, such as → sunspots, → solar flares, → coronal mass ejections, and the → solar wind. The solar magnetic fields are observed from the → Zeeman broadening of spectral lines, → polarization effects on radio emission, and from the channeling of charged particles into visible → coronal streamers. The strength of Sun's average magnetic field is 1 → gauss (twice the average field on the surface of Earth, around 0.5 gauss), and can be as strong as 4,000 Gauss in the neighborhood of a large sunspot.
toroidal magnetic field
meydân-e meqnâtisi-ye cambarvâr
Fr.: champ magnétique toroïdal
A magnetic field which is generated in a → plasma inside a → toroid, as in a → tokamak, by the electric current which spirals around the toroid. Toroidal field has no radial component. → poloidal magnetic field.
uniform magnetic field
meydân-e meqnâtisi-ye yekdis
Fr.: champ magnétique uniforme
A → magnetic field whose direction does not change and whose strength is constant at every point.