Constructing precisely quasi-isodynamic magnetic fields

Abstract

We present a novel method for numerically finding quasi-isodynamic stellarator magnetic fields with excellent fast-particle confinement and extremely small neoclassical transport. The method works particularly well in configurations with only one field period. We examine the properties of these newfound quasi-isodynamic configurations, including their bootstrap currents, particle confinement, and available energy for trapped-electron driven turbulence, as well as the degree to which they change when a finite pressure profile is added. We finally discuss the differences between the magnetic axes of the optimized solutions and their respective initial conditions, and conclude with the prospects for future quasi-isodynamic optimization.

25 pages, 10 figures

References in corpus (6)

• Available energy and ground states of collisionless plasmas
• A quasi-isodynamic configuration with good confinement of fast ions at low plasma $\beta$
• Near-Axis Expansion of Stellarator Equilibrium at Arbitrary Order in the Distance to the Axis
• Single-Stage Stellarator Optimization: Combining Coils with Fixed Boundary Equilibria
• Direct construction of stellarator-symmetric quasi-isodynamic magnetic configurations
• A single-field-period quasi-isodynamic stellarator

Cited by in corpus (15)

• A quasi-isodynamic configuration with good confinement of fast ions at low plasma $\beta$
• Single-Stage Stellarator Optimization: Combining Coils with Fixed Boundary Equilibria
• Direct stellarator coil design using global optimization: application to a comprehensive exploration of quasi-axisymmetric devices
• Robust stellarator optimization via flat mirror magnetic fields
• Magnetic Fields with General Omnigenity
• Bounce-averaged drifts: Equivalent definitions, numerical implementations, and example cases
• MONKES: a fast neoclassical code for the evaluation of monoenergetic transport coefficients
• The residual flow in well-optimized stellarators
• Energetic Particle Tracing in Optimized Quasisymmetric Stellarator Equilibria
• Electron root optimisation for stellarator reactor designs
• The zonal-flow residual does not tend to zero in the limit of small mirror ratio
• Piecewise omnigenous stellarators with zero bootstrap current
• Omnigenous umbilic stellarators
• Efficient Computation of Stellarator Coils with an Augmented Lagrangian Optimization Method
• Near-axis quasi-isodynamic database