MERCREDI 16 JUIN 2010 14 heures Salle Séminaire 5 Centre de Physique Théorique Marseille-Luminy Daniela Grasso CNR-INFM and Politecnico di Torino, Italy Title: Transport barriers for magnetic field lines in 3D collisionless reconnection events Abstract: The development of chaos in three-dimensional magnetic reconnection events is investigated. Areas where the magnetic field is chaotic exist next to regions where the field is more regular. The problem of transport of magnetic field lines between chaotic layers is addressed. It is shown that the Lagrangian Coherent Structures (LCS) exist in regions between chaotic layers and act as barriers for the transport of magnetic field lines.