Project A2


Dr. Jürgen Dreher
Institute for Theoretical Physics I
Ruhr-University Bochum


Multifluid Effects in Flux Rope Dynamics


We will investigate the implications of multifluid effects for the evolution of magnetic flux ropes
by time-dependent numerical simulations with the code 'racoon'. The configurations studied
are arched magnetized plasma loops as they are found naturally, e.g. in the solar corona,
and artificially created in laboratory experiments like 'FlareLab' (see project A5). Our studies
are motivated by the fact that multifluid effects are expected to play a role in the 'FlareLab'
experiment, where the ion skin depth is of the order of several millimeters and the plasma arc
is created by electrical breakdown, for which the neutral gas distribution plays an essential role.
In the course of this project, we will extend the 'racoon' setup used earlier for MHD simulations
of 'FlareLab' [1] to include Hall- and electron pressure gradient terms in the Ohm's law, neutral
gas equations, collisional interaction between the three species and the effects of ionization and
recombination. This numerical model will be used to study the expansion properties of the
plasma arc and its interaction with the overlying strapping field component, carry out detailed
comparisons with the experimental data obtained in project A5, and draw conclusions about the
significance and signatures of multifluid effects with possible implications for their astrophysical