Section Days abstract book 2010.indd - RUB Research School ...

NSE_10
EXPERIMENTAL SIMULATION OF SOLAR
MAGNETIC FLUX TUBES
Felix Mackel, P. Kempkes, H. Stein, J. Tenfelde and H. Soltwisch
Institute for Experimental Physics V
Workgroup Laser and Plasma Physics
Ruhr-Universität Bochum, 44780 Bochum, Germany
email: felix.mackel@ep5.rub.de
A pulsed-power experiment has been designed to produce arc-shaped magnetic flux tubes
similar to ascending solar flares. The tubes are filled with hydrogen plasma and expand with
a velocity of about 2.5 cm/µs, while keeping their minor radius of about 1.5 cm constant
during their lifetime of about 10 µs. In order to characterize the plasma regime and to
investigate relevant magnetohydrodynamic phenomena, accurate data on parameters like
electron density and mean energy are essential.
For measuring the line integrated electron density a CO2 laser interferometer is set up at a
fixed position. Time resolved measurements of the discharge arc’s passage across the
laser beam allow for the measurement of the radial profile of the line-integrated electron
density. Results are compared to measurements taken with an electrostatic probe at the
same position.
The magnetic field of the arc is investigated employing induction probes. From the currentgenerated
magnetic field, information about the arc’s propagation and expansion is obtained.
Furthermore, the derived plasma conditions indicate the possibility of magnetic flux being
frozen into the plasma.