Nonlinear coupling of tearing fluctuations in the Madison Symmetric Torus [electronic resource].
- Washington, D.C. : United States. Dept. of Energy, 1992. and Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- 24 pages : digital, PDF file
- Additional Creators:
- University of Wisconsin--Madison, United States. Department of Energy, and United States. Department of Energy. Office of Scientific and Technical Information
- Restrictions on Access:
- Free-to-read Unrestricted online access
- Three-wave, nonlinear, tearing mode coupling has been measured in the Madison Symmetric Torus (MST) reversed-field pinch (RFP) [Fusion Technol. 19, 131 (1991)] using bispectral analysis of edge magnetic fluctuations resolved in ``k-space. The strength of nonlinear three-wave interactions satisfying the sum rules m₁ + m₂ = m₃ and n₁ + n₂ = n₃ is measured by the bicoherency. In the RFP, m=l, n∼2R/a (6 for MST) internally resonant modes are linearly unstable and grow to large amplitude. Large values of bicoherency occur for two m=l modes coupled to an m=2 mode and the coupling of intermediate toroidal modes, e.g., n=6 and 7 coupled to n=13. These experimental bispectral features agree with predicted bispectral features derived from MHD computation. However, in the experiment, enhanced coupling occurs in the ``crash`` phase of a sawtooth oscillation concomitant with a broadened mode spectrum suggesting the onset of a nonlinear cascade.
- Published through SciTech Connect., 11/01/1992., "doe/er/53198--211", " conf-921103--9", "DE93010131", Meeting of the Division of Plasma Physics of the American Physical Society,Seattle, WA (United States),16-20 Nov 1992., and Ji, H.; Prager, S.C.; Sarff, J.S.; Shen, W.; Almagri, A.F.; Cekic, M.; Den Hartog, D.J.; Fiksel, G.; Hokin, S.A.; Assadi, S.; Sidikman, K.L.; Stoneking, M.R.
- Funding Information:
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