Stable spheromak formation by merging in an oblate flux conserver
- Department of Physics and Astronomy, Swarthmore College, Swarthmore, Pennsylvania 19081-1397 (United States)
- PSI-Center, University of Washington, Seattle, Washington 98195-2250 (United States)
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)
An axisymmetric spheromak formed by the dynamic merging of two smaller spheromaks of the same magnetic helicity in the Swarthmore Spheromak Experiment (SSX) [M. R. Brown, Phys. Plasmas 6, 1717 (1999)] has been observed and characterized. The spheromak is formed in an oblate (tilt stable), trapezoidal, 6 mm wall copper flux conserver in SSX, which is 0.5 m in diameter and L=0.4 m in length at its largest dimensions. This configuration is formed by cohelicity merging of two spheromaks (either both right-handed or both left-handed) in which the merging poloidal fluxes are parallel (i.e., no field reversal for reconnection to occur initially). After a period of dynamic and nonaxisymmetric activity, the configuration ultimately relaxes to an axisymmetric state. A nonaxisymmetric tilted state, very close in total energy to the axisymmetric state, is also sometimes observed. This configuration is characterized by a suite of magnetic probe arrays for magnetic structure B(r,t), ion Doppler spectroscopy for T{sub i} and flow, and interferometry for n{sub e}. The magnetic structures of both states match well to computed eigenstates.
- OSTI ID:
- 21347189
- Journal Information:
- Physics of Plasmas, Vol. 17, Issue 3; Other Information: DOI: 10.1063/1.3334324; (c) 2010 American Institute of Physics; ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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