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arXiv · 2302.01166

Faithful guiding-center orbits in an axisymmetric magnetic field

Alain J. Brizard·Brook C. Hodgeman
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Abstract

The problem of the charged-particle motion in an axisymmetric magnetic geometry is used to assess the validity of higher-order Hamiltonian guiding-center theory, which includes higher-order corrections associated with gyrogauge invariance as well as guiding-center polarization induced by magnetic-field non-uniformity. Two axisymmetric magnetic geometries are considered: a magnetic mirror geometry and a simple tokamak geometry. When a magnetically-confined charged-particle orbit is regular (i.e., its guiding-center magnetic moment is adiabatically invariant), the guiding-center approximation, which conserves both energy and azimuthal canonical angular momentum, is shown to be faithful to the particle orbit when higher-order corrections are taken into account.

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Alain J. Brizard, Brook C. Hodgeman. 2023-02-02. Faithful guiding-center orbits in an axisymmetric magnetic field. https://doi.org/10.1063/5.0145035

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