Oscillating Ponomarenko dynamo in the highly conducting limit

M. Peyrot (1) , A. Gilbert (2) , Franck Plunian (1)

1 LGIT - Laboratoire de Géophysique Interne et Tectonophysique
2 Mathematics Research Institute, School of Engineering, Computing and Mathematics

This paper considers dynamo action in smooth helical flows in cylindrical geometry, otherwise known as Ponomarenko dynamos, with periodic time dependence. An asymptotic framework is developed that gives growth rates and frequencies in the highly conducting limit of large magnetic Reynolds number, when modes tend to be localized on resonant stream surfaces. This theory is validated by means of numerical simulations.

M. Peyrot, A. Gilbert, Franck Plunian. Oscillating Ponomarenko dynamo in the highly conducting limit. Physics of Plasmas, 2008, 15 (12), pp.122104. ⟨10.1063/1.3035911⟩. ⟨insu-00354206⟩