2014/02/18 by Davide Faranda, Mickaël Bourgoin, Mickael Bourgoin +8
Biochemistry, Genetics and Molecular Biology · Engineering · Physics and Astronomy · #Characterization and Applications of Magnetic Nanoparticles #Dynamo #Dynamo theory #Extreme value theory #Fluid dynamics and aerodynamics studies #Geomagnetism and Paleomagnetism Studies #Value (mathematics) #physics.data-an #physics.flu-dyn
paper · pdf · doi:10.1088/1367-2630/16/8/083001
10 pages, 7 figures
arxiv created 2014/02/18 · openalex publication_date 2014/08/01 · arxiv updated 2015/06/18 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We apply a new threshold detection method based on the extreme value theory (EVT) to the von Kármán sodium (VKS) experiment data. The VKS experiment is a successful attempt to get a dynamo magnetic field in a laboratory liquid-metal experiment. We first show that the dynamo threshold is associated with a change of the probability density function of the extreme values of the magnetic field. This method does not require the measurement of response functions from applied external perturbations and thus provides a simple threshold estimate. We apply our method to different configurations in the VKS experiment, showing that it yields a robust indication of the dynamo threshold as well as evidence of hysteretic behaviors. Moreover, for the experimental configurations in which a dynamo transition is not observed, the method provides a way to extrapolate an interval of possible threshold values.