Bochum 2015 – scientific programme

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P: Fachverband Plasmaphysik

P 24: Theory and Modelling III

P 24.8: Talk

Thursday, March 5, 2015, 12:25–12:40, HZO 50

Jet formation and multi-fluid effects in dynamic magnetic flux tubes — •Thomas Tacke and Jürgen Dreher — Theoretische Physik I, Ruhr-Universität Bochum

As part of a collaboration with the coronal loop experiment FlareLab at Bochum university, different aspects of the dynamics of arch-shaped current-carrying magnetic flux tubes are investigated. The equations of magnetohydrodynamics are solved numerically using an initial cylindrical configuration in radial force equilibrium with an axial pressure gradient. The following formation of a plasma jet and its evolving structure within the simulation is then compared to phenomena observed in the electrode region in FlareLab. In a second study, the dispersion relation of an ion acoustic-type instability is derived from fluid equations including collisions between charged and neutral particles. The instability is first investigated numerically in one dimension and its growth compared to the analytical growth rate. Two-dimensional initial equilibrium configurations are derived, resulting in the collisional equivalent of the Harris-sheet and the Bennett pinch. The existence and growth of the instability in these configurations is then investigated and discussed as possible candidates for explaining small density bulges observed in the early phase of numerous discharges in FlareLab.