Quasisymmetry is an unusual symmetry that can be present in toroidal magnetic fields,
enabling the confinement of charged particles and plasma. Here it is shown that both …

Quasi-symmetry can greatly improve the confinement of energetic particles and thermal
plasma in a stellarator. The magnetic field of a quasi-symmetric stellarator at high plasma …

The separation between the last closed flux surface of a plasma and the external coils that
magnetically confine it is a limiting factor in the construction of fusion-capable plasma …

A method is demonstrated to rapidly calculate the shapes and properties of quasi-
axisymmetric and quasi-helically symmetric stellarators. In this approach, optimization is …

Collisionless physics primarily determines the transport of fusion-born alpha particles in 3D
equilibria. Several transport mechanisms have been implicated in stellarator configurations …

This paper presents the calculation of the bounce-averaged drift of trapped particles in a
near-axis framework for axisymmetric and quasisymmetric magnetic fields that possess up …

In the present Letter, first-of-its-kind computer simulations predicting plasma profiles for
modern optimized stellarators—while self-consistently retaining neoclassical transport …

We propose a new method to compute magnetic surfaces that are parametrized in Boozer
coordinates for vacuum magnetic fields. We also propose a measure for quasisymmetry on …

A good understanding of the confinement of energetic ions in non-axisymmetric magnetic
fields is key for the design of reactors based on the stellarator concept. In this work, we …

An important goal of stellarator optimization is to achieve good confinement of energetic
particles such as, in the case of a reactor, alphas created by deuterium–tritium fusion. In this …