Physical Review Letters -- October 18, 1999 -- Volume 83, Issue 16, pp. 3198-3201

Turbulent Dynamos and Magnetic Helicity

Hantao Ji
Princeton Plasma Physics Laboratory, Princeton University, P.O. Box 451, Princeton, New Jersey 08543

(Received 30 April 1999)

It is shown that the turbulent-dynamo alpha effect converts magnetic helicity from the turbulent field to the mean field when the turbulence is electromagnetic, while the magnetic helicity of the mean field is transported across space when the turbulence is electrostatic or due to the electron diamagnetic effect. In all cases, however, the dynamo effect strictly conserves the total helicity except for resistive effects and a small battery effect. Implications for astrophysical situations, especially for the solar dynamo, are discussed.

PACS: 52.30.Jb, 91.25.Cw, 96.60.Hv

Full paper: pdf file (72 Kb) .

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