HR: 17:15h
AN: DI24A-06 INVITED    [Abstracts]
TI: An Experimental Dynamo in a Highly Turbulent Flow.
AU: * Odier, P
EM: podier@ens-lyon.fr
AF: Laboratoire de Physique de l^'Ecole Normale Supérieure de Lyon, 46, allée d'Italie, Lyon, 69007, France
AU: Bourgoin, M
EM: mickael.bourgoin@hmg.inpg.fr
AF: Laboratoire de Physique de l^'Ecole Normale Supérieure de Lyon, 46, allée d'Italie, Lyon, 69007, France
AU: Pinton, J
EM: pinton@ens-lyon.fr
AF: Laboratoire de Physique de l^'Ecole Normale Supérieure de Lyon, 46, allée d'Italie, Lyon, 69007, France
AU: Volk, R
EM: rvolk@ens-lyon.fr
AF: Laboratoire de Physique de l^'Ecole Normale Supérieure de Lyon, 46, allée d'Italie, Lyon, 69007, France
AU: Berhanu, M
EM: michael.berhanu@lps.ens.fr
AF: Laboratoire de Physique Statistique de l^'Ecole Normale Supérieure de Paris, 24 rue Lhomond, Paris, 75005, France
AU: Fauve, S
EM: Stephan.Fauve@lps.ens.fr
AF: Laboratoire de Physique Statistique de l^'Ecole Normale Supérieure de Paris, 24 rue Lhomond, Paris, 75005, France
AU: Mordant, N
EM: nmordant@ens.fr
AF: Laboratoire de Physique Statistique de l^'Ecole Normale Supérieure de Paris, 24 rue Lhomond, Paris, 75005, France
AU: Pétrélis, F
EM: Francois.Petrelis@lps.ens.fr
AF: Laboratoire de Physique Statistique de l^'Ecole Normale Supérieure de Paris, 24 rue Lhomond, Paris, 75005, France
AU: Chiffaudel, A
EM: arnaud.chiffaudel@cea.fr
AF: Service de Physique de l^'Etat Condensé, Direction des Sciences de la Matière, CEA-Saclay, Gif-sur-Yvette, 91191, France
AU: Daviaud, F
EM: francois.daviaud@cea.fr
AF: Service de Physique de l^'Etat Condensé, Direction des Sciences de la Matière, CEA-Saclay, Gif-sur-Yvette, 91191, France
AU: Dubrulle, B
EM: bdubru@drecam.saclay.cea.fr
AF: Service de Physique de l^'Etat Condensé, Direction des Sciences de la Matière, CEA-Saclay, Gif-sur-Yvette, 91191, France
AU: Marié, L
EM: Louis.Marie@ifremer.fr
AF: Service de Physique de l^'Etat Condensé, Direction des Sciences de la Matière, CEA-Saclay, Gif-sur-Yvette, 91191, France
AU: Monchaux, R
EM: Romain.Monchaux@cea.fr
AF: Service de Physique de l^'Etat Condensé, Direction des Sciences de la Matière, CEA-Saclay, Gif-sur-Yvette, 91191, France
AU: Ravelet, F
EM: ravelet@drecam.saclay.cea.fr
AF: Service de Physique de l^'Etat Condensé, Direction des Sciences de la Matière, CEA-Saclay, Gif-sur-Yvette, 91191, France
AB: The dynamo effect is a magnetohydrodynamics instability, allowing the existence of a self-sustaining magnetic field in a flow of an electrically conductive fluid. This effect is considered to be at the origin of the magnetic field of the Earth and the stars. Until now, it had only been evidenced experimentally in cases where internal boundaries guide the flow. We will present the first observation of a dynamo in a homogeneous flow of liquid sodium (VKS2 experiment), where the turbulent fluctuations are of the same order of magnitude as the mean flow. The behaviour of this instability close to the threshold will be described, as well as scaling laws for its saturation. One striking feature of such a dynamo, that makes it very different from the previous constrained dynamos, is that it displays a large variety of dynamical regimes, including chaotic reversals, strongly reminiscent of the observed reversals of the Earth's magnetic field.
DE: 1510 Dynamo: theories and simulations
SC: Study of the Earth's Deep Interior [DI]
MN: 2007 Fall Meeting