44 citations · 432 across the 34 of their papers we have counts for
20 papers · 1 filter
Efficient calculation of magnetic fields from ferromagnetic materials near strong electromagnets, and application to stellarator coil optimization
Matt Landreman, Humberto Torreblanca, Antoine Cerfon
In fusion reactor design, steels under consideration for the blanket are ferromagnetic, so the steel's effect on the plasma physics must be examined. For efficient calculation of t…
Direct, simple, and efficient computation of all components of the virtual-casing magnetic field in axisymmetric geometries with Kapur-Rokhlin quadrature
Evan Toler, Antoine Cerfon, Dhairya Malhotra
In a recent publication (Toler et al. 2023), we demonstrated that for axisymmetric geometries, the Kapur-Rokhlin quadrature rule provided an efficient and high-order accurate metho…
Direct stellarator coil optimization for nested magnetic surfaces with precise quasi-symmetry
Andrew Giuliani, Florian Wechsung, Antoine Cerfon +2
We present a robust optimization algorithm for the design of electromagnetic coils that generate vacuum magnetic fields with nested flux surfaces and precise quasi-symmetry. The me…
Self-consistent formation and steady-state characterisation of trapped high energy electron clouds in the presence of a neutral gas background
G. Le Bars, J. -Ph. Hogge, J. Loizu +3
This study considers the self-consistent formation and dynamics of electron clouds interacting with a background neutral gas through elastic and inelastic (ionisation) collisions i…
Direct computation of magnetic surfaces in Boozer coordinates and coil optimization for quasi-symmetry
Andrew Giuliani, Florian Wechsung, Matt Landreman +2
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 quasi-symmetry on the com…
Stochastic and a posteriori optimization to mitigate coil manufacturing errors in stellarator design
Florian Wechsung, Andrew Giuliani, Matt Landreman +2
It was recently shown in [Wechsung et. al., Proc. Natl. Acad. Sci. USA, 2022] that there exist electromagnetic coils that generate magnetic fields which are excellent approximation…
Accelerating the estimation of energetic particle confinement statistics in stellarators using multifidelity Monte Carlo
Frederick Law, Antoine Cerfon, Benjamin Peherstorfer
In the design of stellarators, energetic particle confinement is a critical point of concern which remains challenging to study from a numerical point of view. Standard Monte Carlo…
FFT-based free space Poisson solvers: why Vico-Greengard-Ferrando should replace Hockney-Eastwood
Junyi Zou, Eugenia Kim, Antoine J. Cerfon
Many problems in beam physics and plasma physics require the solution of Poisson's equation with free-space boundary conditions. The algorithm proposed by Hockney and Eastwood is a…
Single-stage gradient-based stellarator coil design: Optimization for near-axis quasi-symmetry
Andrew Giuliani, Florian Wechsung, Antoine Cerfon +2
We present a new coil design paradigm for magnetic confinement in stellarators. Our approach directly optimizes coil shapes and coil currents to produce a vacuum quasi-symmetric ma…
Dimits shift, avalanche-like bursts, and Solitary propagating structures in the two-field Flux-Balanced Hasegawa-Wakatani model for plasma edge turbulence
Di Qi, Andrew J. Majda, Antoine J. Cerfon
We show that the recently introduced two-field flux-balanced Hasegawa-Wakatani (BHW) model captures the key features of drift-wave turbulent transport mediated by zonal flows obser…
A Flux-Balanced Fluid Model for Collisional Plasma Edge Turbulence: Numerical Simulations with Different Aspect Ratios
Di Qi, Andrew J. Majda, Antoine J. Cerfon
We investigate the drift wave -- zonal flow dynamics in a shearless slab geometry with the new flux-balanced Hasegawa-Wakatani model. As in previous Hasegawa-Wakatani models, we ob…
A Flux-Balanced Fluid Model for Collisional Plasma Edge Turbulence: Model Derivation and Basic Physical Features
Andrew J. Majda, Di Qi, Antoine J. Cerfon
We propose a new reduced fluid model for the study of the drift wave -- zonal flow dynamics in magnetically confined plasmas. Our model can be viewed as an extension of the classic…
Pseudo spectral collocation with Maxwell polynomials for kinetic equations with energy diffusion
Tonatiuh Sanchez-Vizuet, Antoine J. Cerfon
We study the approximation and stability properties of a recently popularized discretization strategy for the speed variable in kinetic equations, based on pseudo spectral collocat…
Fast and spectrally accurate evaluation of gyroaverages in non-periodic gyrokinetic-Poisson simulations
Joseph Guadagni, Antoine J. Cerfon
We present a fast and spectrally accurate numerical scheme for the evaluation of the gyroaveraged electrostatic potential in non-periodic gyrokinetic-Poisson simulations. Our metho…
An analytic scaling relation for the maximum tokamak elongation against n=0 MHD resistive wall modes
Jungpyo Lee, Jeffrey P. Freidberg, Antoine J. Cerfon +1
A highly elongated plasma is desirable in order to increase plasma pressure and energy confinement to maximize fusion power output. However, there is a limit to the maximum achieva…
Effect of the Shafranov shift and the gradient of on intrinsic momentum transport in up-down asymmetric tokamaks
Justin Ball, Felix I. Parra, Jungpyo Lee +1
Tokamaks with up-down asymmetric poloidal cross-sections spontaneously rotate due to turbulent transport of momentum. In this work, we investigate the effect of the Shafranov shift…
Tokamak elongation: how much is too much? I Theory
Jeff P. Freidberg, Antoin Cerfon, Jungpyo Lee
In this and the accompanying paper the problem of the maximally achievable elongation in a tokamak is investigated. The work represents an extension of many earlier studies, which…
ECOM: a fast and accurate solver for toroidal axisymmetric MHD equilibria
Jungpyo Lee, Antoine Cerfon
We present ECOM (Equilibrium solver via COnformal Mapping), a fast and accurate fixed boundary solver for toroidally axisymmetric magnetohydrodynamic equilibria with or without a t…
Exact axisymmetric Taylor states for shaped plasmas
Antoine J. Cerfon, Michael O'Neil
We present a general construction for exact analytic Taylor states in axisymmetric toroidal geometries. In this construction, the Taylor equilibria are fully determined by specifyi…
A fast, high-order solver for the Grad-Shafranov equation
Andras Pataki, Antoine J. Cerfon, Jeffrey P. Freidberg +2
We present a new fast solver to calculate fixed-boundary plasma equilibria in toroidally axisymmetric geometries. By combining conformal mapping with Fourier and integral equation…