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arXiv · 2308.15200

Helicity of the magnetic axes of quasi-isodynamic stellarators

Katia Camacho Mata·Gabriel G. Plunk
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Abstract

In this study, we explore the influence of the helicity of the magnetic axis-defined as the self-linking number of the curve-on the quality of quasi-isodynamic stellarator-symmetric configurations constructed using the near-axis expansion method (Camacho Mata et al. 2022; Plunk et al. 2019). A class of magnetic axes previously unexplored within this formalism is identified when analyzing the axis shape of the QIPC configuration (Subbotin et al. 2006): the case of half-helicity (per field period). We show these shapes are compatible with the near-axis formalism and how they can be used to construct near-axis stellarators with up-to 5 field-periods, $\epsilon_{eff} \approx$ 1.3%, and similar rotational transform as existing conventionally optimized designs, without the need of a plasma boundary optimization.

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Katia Camacho Mata, Gabriel G. Plunk. 2023-08-29. Helicity of the magnetic axes of quasi-isodynamic stellarators. https://arxiv.org/abs/2308.15200

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