We develop the formalism of the first-order near-axis expansion of the
magnetohydrodynamic equilibrium equations described by Garren & Boozer (Phys. Fluids B …

Quasisymmetric stellarators are appealing intellectually and as fusion reactor candidates
since the guiding-centre particle trajectories and neoclassical transport are isomorphic to …

A method is given to rapidly compute quasisymmetric stellarator magnetic fields for plasma
confinement, without the need to call a three-dimensional magnetohydrodynamic …

Physics issues are discussed for compact stellarator configurations which achieve good
confinement by the fact that the magnetic field modulus| B| in magnetic co-ordinates is …

The condition of omnigenity is investigated, and applied to the near-axis expansion of
Garren & Boozer (Phys. Fluids B, vol. 3 (10), 1991a, pp. 2805–2821). Due in part to the …

A systematic theory of the asymptotic expansion of the magnetohydrostatics (MHS)
equilibrium in the distance from the magnetic axis is developed to include arbitrary smooth …

Quasisymmetric stellarators are an attractive class of optimised magnetic confinement
configurations. The property of quasisymmetry (QS) is in practice limited to be approximate …

An asymptotic expansion is performed to obtain quasi-axisymmetric magnetic configurations
that are weakly non-axisymmetric. A large space of solutions is identified, which satisfy the …

A single-field-period quasi-isodynamic stellarator configuration is presented. This
configuration, which resembles a twisted strip, is obtained by the method of direct …

Optimized stellarator configurations and their analytical properties are obtained using a near-
axis expansion approach. Such configurations are associated with good confinement as the …