Title:	Mean-field dynamo in partially ionized plasmas - I
Authors:	Krishan, Vinod Gangadhara, R.T.
Keywords:	MHD Sun: magnetic fields stars: magnetic fields ISM: magnetic fields
Issue Date:	Apr-2008
Publisher:	Wiley Interscience for the RAS
Citation:	Monthly Notices of the Royal Astronomical Society, 2008, Vol.385, p849
Abstract:	There are several astrophysical situations where one needs to study the dynamics of magnetic flux in partially ionized turbulent plasmas. In a partially ionized plasma, the magnetic induction is subjected to the ambipolar diffusion and the Hall effect in addition to the usual resistive dissipation. In this paper, we initiate the study of the kinematic dynamo in a partially ionized turbulent plasma. The Hall effect arises from the treatment of the electrons and the ions as two separate fluids and the ambipolar diffusion due to the inclusion of neutrals as the third fluid. It is shown that these non-ideal effects modify the so-called α effect and the turbulent diffusion coefficient β in a rather substantial way. The Hall effect may enhance or quench the dynamo action altogether. The ambipolar diffusion brings in an α which depends on the mean magnetic field. The new correlations embodying the coupling of the charged fluids and the neutral fluid appear in a decisive manner. The turbulence is necessarily magnetohydrodynamic with new spatial and time-scales. The nature of the new correlations is demonstrated by taking the Alfvénic turbulence as an example.
Description:	Restricted Access. An open-access version is available at arXiv.org (one of the alternative locations)
URI:	http://hdl.handle.net/2289/3650
ISSN:	E-ISSN: 1365-2966 P-ISSN: 0035-8711
Alternative Location:	http://adsabs.harvard.edu/abs/2008MNRAS.385..849K http://arxiv.org/abs/0712.2878 http://dx.doi.org/10.1111/j.1365-2966.2007.12824.x
Copyright:	2008 The Authors & RAS
Appears in Collections:	Research Papers (A&A)

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