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Accueil > Séminaires et conférences > Séminaires, soutenances de thèses et HDR précédents > 2014 > Séminaires 2014 > Le vendredi 6 juin 2014 à 11h

Le vendredi 6 juin 2014 à 11h

Maria Elena Innocenti - Realistic mass ratio simulations of magnetic reconnection with the Multi Level Multi Domain method

Lieu : Palaiseau, salle de l’aile 0, exLIX

Résumé :
In recent years it became evident that stronger interaction between satellite data analysts and numerical modelers can greatly improve our current understanding of magnetic reconnection in space. Think, for example, of how the upcoming launch of the NASA Magnetospheric Multiscale (MMS) mission has increased the efforts of the Particle-In-Cell simulation community towards understanding the multiple temporal and spatial scales which arise in magnetic reconnection.
However, it is precisely the presence of multiple scales that makes the simulation of magnetic reconnection such a challenging tasks : domains with side size of tens or hundreds of ion skin depths di, where di is of the order of 105 m, have to be simulated for tens of minutes or hours to capture the "big picture". Additionally, if electron scale processes need to be resolved, spatial resolutions of the order of the electron skin depth de (de - 103 m) and temporal resolutions of the order of a small fraction of the ion plasma frequency wpi (wpi - 10�3 s) have to be used. These simulations are extremely computationally expensive, even with an implicit code, which already allows to lower the computing costs by bypassing the strict stability constraints of explicit PIC codes.
We propose here a simulation technique to make these problems tractable, the Multi Level Multi Domain method introduced in Innocenti et al. (2013) and Beck et al. (2013). The method combines the advantages of implicit algorithms and adaptivity. The use of the Implicit Moment Method (Vu and Brackbill, 1992) gives a high level of freedom in the choice of the temporal and spatial resolution to use, while with adaptivity it is possible to simulate with higher resolution only the fraction of the domain where faster and smaller scale processes are expected. Large domain simulations of reconnection with realistic mass ratio and local electron scale resolution are now possible.


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Tutelles : CNRS Ecole Polytechnique Sorbonne Université Université Paris Sud Observatoire de Paris Convention : CEA
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Exploitant du site : Laboratoire de Physique des Plasmas, Ecole Polytechnique route de Saclay F-91128 PALAISEAU CEDEX
Hébergeur : Laboratoire de Physique des Plasmas, Ecole Polytechnique route de Saclay F-91128 PALAISEAU CEDEX
Directeur de la publication : Pascal Chabert (Directeur)