Resistive and ferritic-wall plasma dynamos in a sphere
Abstract
We numerically study the effects of varying electric conductivity and magnetic permeability of the bounding wall on a kinematic dynamo in a sphere for parameters relevant to Madison plasma dynamo experiment (MPDX). The dynamo is excited by a laminar, axisymmetric flow of von Karman type. The flow is obtained as a solution to the Navier-Stokes equation for an isothermal fluid with a velocity profile specified at the sphere's boundary. The properties of the wall are taken into account as thin-wall boundary conditions imposed on the magnetic field. It is found that an increase in the permeability of the wall reduces the critical magnetic Reynolds number Rm_cr. An increase in the conductivity of the wall leaves Rm_cr unaffected, but reduces the dynamo growth rate.
Cite
@article{arxiv.1205.4696,
title = {Resistive and ferritic-wall plasma dynamos in a sphere},
author = {I. V. Khalzov and B. P. Brown and E. J. Kaplan and N. Katz and C. Paz-Soldan and K. Rahbarnia and E. J. Spence and C. B. Forest},
journal= {arXiv preprint arXiv:1205.4696},
year = {2012}
}