HR: 1340h
AN: SH33B-0374    [Abstracts]
TI: Experimental and theoretical investigation of current driven rotating kink modes in a non-line tied screw pinch
AU: Furno, I
EM: ivofurno@yahoo.com
AF: Los Alamos National Laboratory, M.S. E526, Los Alamos, NM 874545 United States
AU: * Intrator, T
EM: intrator@lanl.gov
AF: Los Alamos National Laboratory, M.S. E526, Los Alamos, NM 874545 United States
AU: Abbate, S
EM: abbate@lanl.gov
AF: Los Alamos National Laboratory, M.S. E526, Los Alamos, NM 874545 United States
AU: Madziwa, T
EM: Madziwa@lanl.gov
AF: Los Alamos National Laboratory, M.S. E526, Los Alamos, NM 874545 United States
AU: Light, A
EM: alight@lanl.gov
AF: Los Alamos National Laboratory, M.S. E526, Los Alamos, NM 874545 United States
AU: Ryutov, D
EM: ryutov1@llnl.gov
AF: Lawrence Livermore National Laboratory, Livermore, Livermore, CA 94551 United States
AB: Magnetic fields are embedded in astrophysical, solar, space, and laboratory plasmas. For many of these cases, the magnetic field has both azimuthal and axial components resulting in a screw pinch magnetic configuration. One of the most salient features of screw pinches, is the development of the m=1 global kink mode when a critical current is exceeded. In this study, we suggest a simplified description of kink mode in a screw pinch with a length much exceeding its radius. Our theory presents a unified way for describing such effects as boundary conditions at the electrodes (including the sheaths), finite plasma resistivity, and plasma axial flow. This new approach is particularly efficient in the problems with non-ideal (sheath) boundary conditions at the end electrodes, the finite plasma resistivity, and the case of a substantial axial flow. For the non-ideal situation, we find instability in the domain well below the classical Kruskal-Shafranov limit. The presence of an axial flow causes the onset of a rotation of the kink and strong axial "skewness" of the eigenfunction. We compare the theory predictions with recent results in the RSX experiment a Los Alamos National Laboratory. Agreement with new theory predictions include flow generated finite rotation frequency, and a "soft" kink threshold lower than the Kruskal-Shafranov critical current.
DE: 7526 Magnetic reconnection (2723, 7835)
DE: 7827 Kinetic and MHD theory
DE: 7831 Laboratory studies and experimental techniques
DE: 7836 MHD waves and instabilities (2149, 2752, 6050)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005