Physics:Kink instability

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Short description: Current-driven plasma instability
One of the earliest photos of the kink instability in action - the 3 by 25 cm pyrex tube at Aldermaston.

A kink instability (also known as a kink oscillation or kink mode) is a current-driven plasma instability characterized by transverse displacements of a plasma column's cross-section from its center of mass without any change in the characteristics of the plasma. It typically develops in a thin plasma column carrying a strong axial current which exceeds the Kruskal–Shafranov limit[1][2][3] and is sometimes known as the Kruskal–Shafranov (kink) instability,[4][5] named after Martin David Kruskal and Vitaly Shafranov.

The kink instability was first widely explored in fusion power machines with Z-pinch configurations in the 1950s.[6] It is one of the common magnetohydrodynamic instability modes which can develop in a pinch plasma and is sometimes referred to as the [math]\displaystyle{ m=1 }[/math] mode.[6] (The other is the [math]\displaystyle{ m=0 }[/math] mode known as the sausage instability.)

If a "kink" begins to develop in a column the magnetic forces on the inside of the kink become larger than those on the outside, which leads to growth of the perturbation.[6][7] As it develops at fixed areas in the plasma, kinks belong to the class of "absolute plasma instabilities", as opposed to convective processes.

References

  1. Ryutov, D. D.; Furno, I.; Intrator, T. P.; Abbate, S.; Madziwa-Nussinov, T. (2006). "Phenomenological theory of the kink instability in a slender plasma column" (in en). Physics of Plasmas 13 (3): 032105. doi:10.1063/1.2180667. ISSN 1070-664X. Bibcode2006PhPl...13c2105R. https://digital.library.unt.edu/ark:/67531/metadc881368/. 
  2. DeHaas, Timothy; Gekelman, Walter; Van Compernolle, Bart (2015). "Experimental study of a linear/non-linear flux rope" (in en). Physics of Plasmas 22 (8): 082118. doi:10.1063/1.4928888. ISSN 1070-664X. Bibcode2015PhPl...22h2118D. 
  3. Oz, E.; Myers, C. E.; Yamada, M.; Ji, H.; Kulsrud, R. M.; Xie, J. (2011). "Experimental verification of the Kruskal-Shafranov stability limit in line-tied partial-toroidal plasmas" (in en). Physics of Plasmas 18 (10): 102107. doi:10.1063/1.3647567. ISSN 1070-664X. Bibcode2011PhPl...18j2107O. https://digital.library.unt.edu/ark:/67531/metadc830825/. 
  4. Cap, Ferdinand F. (2013-09-11) (in en). Handbook on Plasma Instabilities. Academic Press. ISBN 9781483271057. https://books.google.com/books?id=Jc43BQAAQBAJ&q=%22Kruskal%E2%80%93Shafranov+instability%22. 
  5. Hasegawa, A. (2012-12-06) (in en). Plasma Instabilities and Nonlinear Effects. Springer Science & Business Media. ISBN 9783642659805. https://books.google.com/books?id=0CHqCAAAQBAJ&q=%22Kruskal%E2%80%93Shafranov+instability%22. 
  6. 6.0 6.1 6.2 Zohuri, Bahman (2017-02-23) (in en). Magnetic Confinement Fusion Driven Thermonuclear Energy. Springer. pp. 46–48. ISBN 9783319511771. https://books.google.com/books?id=Aj02DgAAQBAJ&dq=%22absolute+plasma+instabilities%22%2C+as+opposed+to+convective+processes&pg=PA46. 
  7. Plasma Dictionary