Application of Lagrangian techniques for calculating the on-axis rotational transform

Guinchard, S. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0009000466173956); Sengupta, W. [Princeton Univ., NJ (United States)] (ORCID:0000000234152067); Hudson, S. R. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0000000315302733)

doi:10.1017/s0022377824001648

DOE OSTI · 2536699

Application of Lagrangian techniques for calculating the on-axis rotational transform

Guinchard, S. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0009000466173956)·Sengupta, W. [Princeton Univ., NJ (United States)] (ORCID:0000000234152067)·Hudson, S. R. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0000000315302733)

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Abstract

The Floquet exponents of periodic field lines are studied through the variations of the magnetic action on the magnetic axis, which is assumed to be elliptical. The near-axis formalism developed by Mercier, Solov'ev and Shafranov is combined with a Lagrangian approach. The on-axis Floquet exponent is shown to coincide with the on-axis rotational transform. A discrete solution suitable for numerical implementation is introduced, which gives the Floquet exponents as solutions to an eigenvalue problem. This discrete formalism expresses the exponents as the eigenvalues of a $6$ X $6$ matrix.

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70 PLASMA PHYSICS AND FUSION TECHNOLOGY Lagrangian integration Mercier Solov'ev-Shafranov magnetic action near-axis expansion rotational transform variation

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BibTeX RIS

Guinchard, S. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0009000466173956), Sengupta, W. [Princeton Univ., NJ (United States)] (ORCID:0000000234152067), Hudson, S. R. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0000000315302733). 2025-02-12. Application of Lagrangian techniques for calculating the on-axis rotational transform. https://doi.org/10.1017/s0022377824001648

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