Berlin 2014 – wissenschaftliches Programm
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P: Fachverband Plasmaphysik
P 17: Poster Session - Helmholtz Graduate School for Plasma Physics
P 17.1: Poster
Mittwoch, 19. März 2014, 16:30–18:30, SPA Foyer
Acceleration of test particles in imbalanced magnetohydrodynamic turbulence — •Martin S. Weidl1,2, Bogdan Teaca2,3,4, and Frank Jenko1,2 — 1Max-Planck-Institut für Plasmaphysik, EURATOM-Assoziation, Boltzmannstraße 2, 85748 Garching, Germany — 2Max-Planck/Princeton Center for Plasma Physics — 3Applied Mathematics Research Centre, Coventry University, Coventry CV1 5FB, United Kingdom — 4Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Straße 2, 37191 Katlenburg-Lindau, Germany
The spatial structure and the strength of the turbulent electric field in a plasma are strongly affected by cross-helicity, a quantity which measures the level of alignment of the velocity and the magnetic field. Although often neglected in numerical magnetohydrodynamic (MHD) simulations, cross-helicity can reach significant values in many astrophysical plasmas, such as the solar wind.
We study the transport and acceleration properties of charged particles in plasmas with non-zero cross-helicity, or imbalanced turbulence, by performing test particle simulations in parallel with three-dimensional MHD simulations. The cross-helicity level of the MHD steady-state is controlled by using a correlated forcing scheme for velocity and magnetic fields. We discuss the decrease of the turbulent heating rate in systems with non-zero cross-helicity and compare its scaling with theoretical predictions. Our results are expected to be relevant for any plasma in which turbulent heating is important, for example the heating of dust particles in the interstellar medium.