HR: 1340h
AN: GP33A-0932 [Abstracts]
TI: Simulations and Measurements of Fluctuation-Driven Magnetic Fields in a Liquid Metal Experiment
AU: * Spence, E
EM: ejspence@erdw.ethz.ch
AF: ETH Zürich
Institut für Geophysik, ETH Zürich
Institut für Geophysik, Zürich, 8093, Switzerland
AU: Nornberg, M
EM: mdnornberg@pppl.gov
AF: Princeton Plasma Physics Laboratory, Princeton Plasma Physics Laboratory, Princeton, NJ
08543, United States
AU: Kendrick, R
EM: rdkendri@wisc.edu
AF: University of Wisconsin-Madison
Department of Physics, 1150 University Avenue, Madison, WI 53706, United States
AU: Bayliss, A
EM: rabayliss@wisc.edu
AF: University of Wisconsin-Madison
Department of Engineering Physics, 1500 Engineering Drive, Madison, WI 53706, United States
AU: Forest, C
EM: cbforest@wisc.edu
AF: University of Wisconsin-Madison
Department of Physics, 1150 University Avenue, Madison, WI 53706, United States
AB:
The Madison Dynamo Experiment is designed to demonstrate magnetic self-excitation using flowing liquid
sodium in a spherical geometry. A turbulent flow is produced in the experiment by two counter-rotating impellers.
The role of turbulent velocity and magnetic field fluctuations in magnetic field generation is explored by applying
an external magnetic field to the flowing sodium and measuring the induced magnetic field. The mean velocity
field of the experiment is determined by measuring the velocity field in a dimensionally identical water experiment.
The magnetic fields induced by both the mean flow and by the fluctuations are then calculated. The presence of
a strong diamagnetic field, generated by fluctuations, is identified and its spatial structure presented. Such a
fluctuation-driven magnetic field is also found in simulations of the experiment, which are used to determine the
nature of the fluctuations, and how they induce the diamagnetic field.
DE: 1510 Dynamo: theories and simulations
DE: 1599 General or miscellaneous
DE: 2149 MHD waves and turbulence (2752, 6050, 7836)
DE: 4490 Turbulence (3379, 4568, 7863)
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2007 Fall Meeting