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Lundquist number

In plasma physics, the Lundquist number (denoted by S) is the dimensionless ratio of an Alfvén wave crossing timescale to a diffusion timescale. In SI units, it is given by


where L is a typical length scale, μ0 is the permeability of free space, V_A=\frac{B}{\sqrt{\mu_0\rho}} is the Alfvén speed, and η is the plasma resistivity. High Lundquist numbers indicate highly conducting plasmas, while low Lundquist numbers indicate more resistive plasmas. Laboratory plasma experiments typically have Lundquist numbers between 50 − 108, while in astrophysical situations the Lundquist number can be greather than 1020. Considerations of Lundquist number are especially important in magnetic reconnection.


  • Eric Priest, Terry Forbes, Magnetic Reconnection, Cambridge University Press 2000, ISBN 0521481791, contents and sample chapter online
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Lundquist_number". A list of authors is available in Wikipedia.
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