Intermittent electromagnetic transport in hot low-β tokamak edge plasma

Intermittent transport of plasma at the edge of fusion devices is known to contribute considerably to overall energy and particle fluxes coming to the first wall of installations. Plasma ejections driven by turbulence come in the form of blobs, thin filaments strongly elongated along the direction of the magnetic field lines. In this contribution, we analyze electromagnetic dynamics of blobs in hot, yet sufficiently dilute edge plasma, characterized by values of the plasma parameter β < m_e/m_i. The physical and mathematical models describing blob dynamics are presented. The impact of the collisional skin effect, excitation of the Alfvén waves, and their reflection from the conducting surfaces (located at the ends of open magnetic field lines intersecting the installation plasma-facing components) on parameters of blob transport are analyzed. Possible modifications of the sheath boundary conditions for closing the system of MHD equations are considered. The qualitative conclusions on peculiarities of filament dynamics in hot edge plasma are compared with results of numerical modeling of seeded blob dynamics under conditions similar to the DIII-D and T-15MD tokamaks.