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arXiv · 2007.04529

Bifurcations of the magnetic axis and the alternating-hyperbolic sawtooth

C. B. Smiet·G. J. Kramer·S. R. Hudson
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Abstract

We present a sawtooth model that explains observations where the central safety factor, $q_0$, stays well below one, which is irreconcilable with current models that predict a reset to $q_0=1$ after the crash. We identify the structure of the field around the magnetic axis with elements of the Lie group $\mathrm{SL}(2,\mathbb{R})$ and find a transition to an alternating-hyperbolic geometry when $q_0=2/3$. This transition is driven by an ideal MHD instability and leads to a chaotic magnetic field near the axis.

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C. B. Smiet, G. J. Kramer, S. R. Hudson. 2020-07-09. Bifurcations of the magnetic axis and the alternating-hyperbolic sawtooth. https://doi.org/10.1088/1741-4326/ab9a0d

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