Experimental Verification of the Kruskal-Shafranov Stability Limit in Line-Tied Partial Toroidal Plasmas

Oz, E. ; Myers, C. E. ; Yamada, M. ; Ji, H. ; Kulsrud, R. M. ; Xie, J.

关键词: ELECTRIC CURRENTS;    ELECTRODES;    KINK INSTABILITY;    MAGNETIC PROBES;    MAGNETIC RECONNECTION;    OSCILLATIONS;    STABILITY;    VERIFICATION Gas Discharges;    Kink Instability;    MHD Instability;   

DOI  :  10.2172/1030419
RP-ID  :  PPPL-4642
PID  :  OSTI ID: 1030419
Others  :  TRN: US1200431

学科分类：原子、分子光学和等离子物理

美国|英语

来源: SciTech Connect

【 摘 要 】

The stability properties of partial toroidal flux ropes are studied in detail in the laboratory, motivated by ubiquitous arched magnetic structures found on the solar surface. The flux ropes studied here are magnetized arc discharges formed between two electrodes in the Magnetic Reconnection Experiment (MRX) [Yamada et al., Phys. Plasmas, 4, 1936 (1997)]. The three dimensional evolution of these flux ropes is monitored by a fast visible light framing camera, while their magnetic structure is measured by a variety of internal magnetic probes. The flux ropes are consistently observed to undergo large-scale oscillations as a result of an external kink instability. Using detailed scans of the plasma current, the guide field strength, and the length of the flux rope, we show that the threshold for kink stability is governed by the Kruskal-Shafranov limit for a flux rope that is held fixed at both ends (i.e., qa = 1).