Filament Dynamics in Strongly Magnetized Plasmas

The topic of my dissertation are investigations of turbulent motions and fluctuation-driven transport in the edge region of magnetically confined plasmas. Since early fusion experiments, one universally observes high fluctuations in the edge region of mag netically confined plasmas. In the outermost region of the confined plasma, the scrape-off layer (SOL), where magnetic field lines intersect material surfaces, these fluctuations are accompanied by large transport events. Progress in experimental techniqu es and theoretical modeling allowed to link these transport events to the motions of plasma filaments which are elongated along the magnetic field lines and localized in the drift-plane perpendicular to the magnetic field. The filaments contain excess p article density and heat which is transported outwards towards the vessel walls and material surfaces. This leads to an increased plasma flux to the main chamber wall and poses significant problems to the steady-state operation of fusion plasma experiment s including main chamber recycling, material mitigation and disruptions that lead to a sudden loss of plasma confinement. For a better qualitative understanding of these effects, dynamic properties of isolated plasma filaments are of great interest for th e fusion community. So far, most studies model plasma filaments as two-dimensional structures, where processes parallel to the magnetic field are described by zero-dimensional averages. My project aims to develop a three-dimensional model for propagatio n of plasma filaments that explicitly models transport processes along the magnetic field lines and also models interactions between perturbations of the plasma profiles and background profiles. The competition between parallel expansion of the filaments and radial transport will be investigated with special consideration physical mechanisms involved in the parallel expansions and their impact on radial propagation.