Title: Linear and Nonlinear Dynamos
Speaker: Professor F. Cattaneo
Speaker Info: U. Chicago
Brief Description:
Special Note:
Abstract:
The generation of magnetic fields by the turbulent motions of a highly conducting fluid---dynamo action---provides a natural explanation for the ubiquitous occurrence of magnetic fields in the universe. Classically, the dynamo problem has been most extensively studied in the kinematic regime, i.e. in the limiting case when the Lorentz force is negligible and the velocity can be prescribed a priori. In a realistic situation the (exponential) growth of the magnetic field eventually leads to a break--down of the kinematic hypothesis and, physically, to the saturation of the dynamo process through a modification of the velocity field. In this talk we review some recent ideas concerning the nature of the saturation mechanism and the resulting nonlinear dynamo state.Date: Friday, February 07, 1997