Selfconsistent theory of meanfield electrodynamics
Abstract
Meanfield electrodynamics, including both α and β effects while accounting for the effects of smallscale magnetic fields, is derived for incompressible magnetohydrodynamics. The principal result is α=(α_{0}+β_{0}R.∇×R)/(1+R^{2}), β=β_{0} where α_{0},β_{0} are conventional kinematic dynamo parameters, the reduction factor is proportional to the mean magnetic field R=R^{1/2}_{m}B/(ρV^{2})^{1/2}, R_{m} is the magnetic Reynolds number, and V is the characteristic turbulent velocity. This result follows from a generalization of the Zeldovich theorem to three dimensions, exploiting magnetic helicity balance.
 Publication:

Physical Review Letters
 Pub Date:
 March 1994
 DOI:
 10.1103/PhysRevLett.72.1651
 Bibcode:
 1994PhRvL..72.1651G
 Keywords:

 47.65.+a;
 03.50.De;
 91.25.Cw;
 Classical electromagnetism Maxwell equations;
 Origins and models of the magnetic field;
 dynamo theories