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Encyclopedia > Alfven wave

An Alfvén wave, named after Hannes Alfvén, is a type of magnetohydrodynamic (or hydromagnetic) wave. An Alfvén wave in plasma is produced by ions low frequency oscillations about their equilibrium positions. An Alfvén wave is represented by a sine-wave shaped magnetic field variation confined to a plane. In an electrically charged gas, the magnetic field wave period vibrations are perpendicular to the direction of propagation of the wave (known as a transverse wave).


See also

Further readings

  • Alfvčn, H. "Cosmic Plasma". Holland. 1981.
  • Otani, N. F., "Application of Nonlinear Dynamical Invariants in a Single Electromagnetic Wave to the Study of the Alfvén-Ion-Cyclotron Instability (http://content.aip.org/PFLDAS/v31/i6/1456_1.html)", Physics of Fluids 31, 1456-1464 (1988).
  • Silberstein, M., and N. F. Otani, "Computer simulation of Alfvén waves and double layers along auroral magnetic field lines (http://otani.vet.cornell.edu/papers/silberstein_otani_1994.pdf)", Journal of Geophysical Research 99, 6351-6365 (1994). (PDF)
  • Cramer, N. F., and S. V. Vladimirov, "Alfvén Waves in Dusty Interstellar Clouds (http://www.atnf.csiro.au/pasa/14_2/cramer/paper/)". PASA, 14 (2).
  • Otani, N. F., "The Alfvén ion-cyclotron instability, simulation theory and techniques". Journal of Computational Physics 78, 251-277 (1988).

External links and references

  • Weisstein, Eric W., "Alfvén Wave (http://scienceworld.wolfram.com/physics/AlfvenWave.html)". Wolfram Research, Inc., Champaign, IL. 2004.
  • Otani, N. F., "Typical Alfvén wave simulation (http://otani.vet.cornell.edu/auroral_accel/stdmovie.html)". Particle Simulations of Auroral Electron Acceleration (http://otani.vet.cornell.edu/auroral_accel/). 2004.
  • Maggs, J., et. al., "Laboratory Studies of Space Relevant Alfvén Wave Processes (http://lasp.colorado.edu/alfconf3/AA_maggs.pdf)". Department of Physics and Astronomy, UCLA, Los Angeles, CA. 2004. (PDF)
  • Jaun, Andre, et. al., "Global waves in resistive and hot Tokamak plasmas - Alfvén wave (http://www.nada.kth.se/~jaun/Research/pub/CPC95/node20.html)". Ecole Polytechnique Federale de Lausanne (Switzerland). Comput. Phys. Commun. vol.92, 1995.
  • Vondrak, Richard, "Alfvén Wave (http://lep694.gsfc.nasa.gov/lepedu/glossary.html#Alfven_Wave)". Laboratory for Extraterrestrial Physics, NASA/Goddard Space Flight Center, Greenbelt, MD USA. 2004.
  • Champeaux, Stephanie, Dimitri Laveder, Thierry Passot, and Pierre-Louis Sulem, "Alfvén Wave Filamentation (http://www.obs-nice.fr/passot/filamentation/AWfil.html)". 2004.



  Results from FactBites:
 
Alfven Wave Interactions (467 words)
This corresponds to wavelengths reaching an Earth radius - this long-scale coherence, coupled with the notion that the wave is carried by ions and is capable of transporting significant energy in the form of Poynting flux towards the earth, indicates that Alfven waves may play a significant role in magnetosphere-ionosphere coupling.
This is accomplished by treating it as a wave in a dielectric medium, with the dielectric constant and the magnetic permeability expressed in terms of the plasma density and the background magnetic field.
The dielectric constant of an Alfven wave is e = 1 + c^2/VA^2, where VA is the Alfven speed and c is the speed of light.
HANNES ALFVEN Hannes Alfven (3174 words)
Alfven was the first to predict (in 1963) the large scale filamentary structure of the universe, a discovery that confounded astrophysicists in 1991 and added to the woes of Big Bang cosmology.
Yet in 1939, when Alfven submitted the paper to the leading American journal Terrestrial Magnetism and Atmospheric Electricity, the paper was rejected on the ground that it did not agree with the theoretical calculations of Chapman and his colleagues.
Alfven was forced to publish this seminal paper in a Swedish-language journal not readily accessible to the worldwide scientific community.
  More results at FactBites »


 
 

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