HR: 1330h
AN: SH42B-0518    [PDF]
TI: Experimental Investigation of the Stability of a Single and Multiple Magnetic Flux Ropes
AU: * Furno, I
EM: furno@lanl.gov
AF: P-24 Plasma Physics Division, Los Alamos National Laboratory, Los Alamos, NM 87544 United States
AU: Intrator, T
EM: intrator@lanl.gov
AF: P-24 Plasma Physics Division, Los Alamos National Laboratory, Los Alamos, NM 87544 United States
AU: Hemsing, E
EM: ehemsing@lanl.gov
AF: P-24 Plasma Physics Division, Los Alamos National Laboratory, Los Alamos, NM 87544 United States
AB: Both the stability of a single magnetic flux rope and the interaction between multiple magnetic flux ropes are fundamental issues in the dynamics of the solar corona. Examples are in coronal mass ejections, in which highly twisted flux ropes are believed to play a crucial role, and in solar flares and large-scale eruptions in which transport of twist through magnetic reconnection is observed between distinct coronal flux systems. To study the interaction of magnetic flux ropes in a controlled laboratory environment, we use the Reconnection Scaling eXperiment (RSX) device at Los Alamos National Laboratory, which was originally designed to study three-dimensional magnetic reconnection during the coalescence of parallel current channels. Commercial plasma guns are used to inject magnetic helicity into hydrogen plasma column ($r = 2$ cm radius, $L = 0.2-3$ m length). Multiple flux ropes carrying currents up to 1 kA are created along the axial direction of a 4 m linear vacuum vessel. A set of 12 identical external coils surrounding the vessel provides an axial magnetic field parallel to the current channels. The azimuthal ($B_{\theta} = 0-100$ Gauss) and axial ($B_z = 0-1000$ Gauss) magnetic field components as well as the plasma density ($10^{12}-10^{14}$ cm$^{-3}$) can be varied independently. In particular, the twist of magnetic field lines, defined by $\Phi = LB_{\theta} / rB_z$, can be scaled in the range $1 < \Phi < 10$ independently of the plasma collisionality. In the present work, the stability of single flux rope and the interaction of two flux ropes are studied in the RSX operational space. Magnetic data and visible light emission from a fast CCD camera are presented showing twisting and braiding of magnetic flux ropes.
DE: 7831 Laboratory studies
DE: 7835 Magnetic reconnection
DE: 7871 Waves and instabilities
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting