3 papers
physics.plasm-ph2020
Approximate symmetries of guiding-centre motion
Joshua W. Burby, Nikos Kallinikos, Robert S. MacKay
Quasisymmetry builds a third invariant for charged-particle motion besides energy and magnetic moment. We address quasisymmetry at the level of approximate symmetries of first-orde…
physics.plasm-ph2020
Generalized Grad-Shafranov equation for non-axisymmetric MHD equilibria
J. W. Burby, N. Kallinikos, R. S. MacKay
The structure of static MHD equilibria that admit continuous families of Euclidean symmetries is well understood. Such field configurations are governed by the classical Grad-Shafr…
math-ph2019
Some mathematics for quasi-symmetry
Joshua W. Burby, Nikos Kallinikos, Robert S. MacKay
Quasi-symmetry of a steady magnetic field means integrability of first-order guiding-centre motion. Here we derive many restrictions on the possibilities for a quasi-symmetry. We a…