On the mean field dynamo with Hall effect
Abstract
Context: .MHD turbulence with Hall effect.
Aims: .Study how Hall effect modifies the quenching process of the electromotive force (e.m.f.) in Mean Field Dynamo (MFD) theories.
Methods: .We write down the evolution equations for the e.m.f. and for the large and small scale magnetic helicity, treat Hall effect as a perturbation and integrate the resulting equations, assuming boundary conditions such that the total divergencies vanish.
Results: .For forcefree large scale magnetic fields, Hall effect acts by coupling the small scale velocity and magnetic fields. For the range of parameters considered, the overall effect is a stronger quenching of the e.m.f. than in standard MHD and a damping of the inverse cascade of magnetic helicity.
Conclusions: .In astrophysical environments characterized by the parameters considered here, Hall effect would produce an earlier quenching of the e.m.f. and consequently a weaker large scale magnetic field.
 Publication:

Astronomy and Astrophysics
 Pub Date:
 June 2006
 DOI:
 10.1051/00046361:20054111
 arXiv:
 arXiv:astroph/0603348
 Bibcode:
 2006A&A...452..773K
 Keywords:

 magnetohydrodynamics (MHD);
 plasmas;
 turbulence;
 Astrophysics;
 Physics  Plasma Physics
 EPrint:
 8 pages, 4 figures. Accepted by A&