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Related papers: Near-axis quasi-isodynamic database

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In this work we consider the problem of optimizing a stellarator subject to hard constraints on the design variables and physics properties of the equilibrium. We survey current numerical methods for handling these constraints, and…

Plasma Physics · Physics 2024-11-20 Rory Conlin , Patrick Kim , Daniel W. Dudt , Dario Panici , Egemen Kolemen

In this work, several key scaling laws of the quasi-static magnetic compression of field reversed configuration (FRC) plasma [Spencer, Tuszewski, and Linford, 1983] are amended from a series of 2D FRC MHD equilibriums numerically obtained…

The capability to model the nonlinear magnetohydrodynamic (MHD) evolution of stellarator plasmas is developed by extending the M3D-$C^1$ code to allow non-axisymmetric domain geometry. We introduce a set of logical coordinates, in which the…

Plasma Physics · Physics 2021-07-13 Yao Zhou , N. M. Ferraro , S. C. Jardin , H. R. Strauss

We propose a combination of cluster analysis and stochastic process analysis to characterize high-dimensional complex dynamical systems by few dominating variables. As an example, stock market data are analyzed for which the dynamical…

Statistical Finance · Quantitative Finance 2015-03-10 Philip Rinn , Yuriy Stepanov , Joachim Peinke , Thomas Guhr , Rudi Schäfer

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 method is based on a bilevel optimization problem, where the…

Plasma Physics · Physics 2023-04-26 Andrew Giuliani , Florian Wechsung , Antoine Cerfon , Matt Landreman , Georg Stadler

We propose a novel approach for constructing training databases for Machine-Learned Interatomic Potential (MLIP) models, specifically designed to capture phase properties across a wide range of conditions. The framework is uniquely…

Materials Science · Physics 2025-12-03 Vincent G. Fletcher , Albert P. Bartók , Livia B. Pártay

Using a novel optimization procedure it has been shown that the Helically Symmetric eXperiment (HSX) stellarator can be optimized for reduced trapped-electron-mode (TEM) instability [M.J.~Gerard et al., \textit{Nucl.~Fusion} \textbf{63}…

We consider the problem of computing the maximal invariant set of discrete-time black-box nonlinear systems without analytic dynamical models. Under the assumption that the system is asymptotically stable, the maximal invariant set…

Systems and Control · Electrical Eng. & Systems 2021-05-31 Zheming Wang , Raphaël M. Jungers

Reduced magnetohydrodynamic (MHD) equations are used to study the nonlinear dynamics of external kinks in a quasi-axisymmetric (QA) stellarator with varying fractions of external rotational transform. The large bootstrap currents associated…

Plasma Physics · Physics 2021-05-13 Rohan Ramasamy , Matthias Hoelzl , Erika Strumberger , Karl Lackner , Sibylle Günter

The optimized stellarator is an attractive concept for which the averaged particle radial drift is zero, and the single particle loss can be significantly reduced. But for the reactor design, global physics such as turbulent transport also…

Plasma Physics · Physics 2026-05-05 Xishuo Wei , Handi Huang , Haotian Chen , Hongxuan Zhu , Zhe Bai , Samuel Williams , Zhihong Lin

Due to their simultaneous optimization for radial and parallel neoclassical transport, quasi-isodynamic fields have been the main choice of stellarator magnetic configuration for most fusion reactor candidates in recent years. However,…

Plasma Physics · Physics 2026-03-16 J. L. Velasco , I. Calvo , V. Fernández-Pacheco , M. Padidar , H. Liu , E. Sánchez , G. Yu , C. Zhu

The near-axis description of optimised stellarator fields has proven to be a powerful tool both for design and understanding of this magnetic confinement concept. The description consists of an asymptotic model of the equilibrium in the…

Plasma Physics · Physics 2025-06-06 Dario Panici , Eduardo Rodriguez , Rory Conlin , Daniel Dudt , Egemen Kolemen

We apply a continuation method to recently optimized stellarator equilibria with excellent quasi-axisymmetry (QA) to generate new equilibria with a wide range of rotational transform profiles. Using these equilibria, we investigate how the…

Plasma Physics · Physics 2024-01-18 Stefan Buller , Matt Landreman , John Kappel , Rahul Gaur

A kinetic treatment is developed for collisionless magnetized plasmas occurring in high-temperature, low-density astrophysical accretion disks, such as are thought to be present in some radiatively-inefficient accretion flows onto black…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Claudio Cremaschini , John C. Miller , Massimo Tessarotto

We present a flexible, detailed model for the evolution of galactic discs in a cosmological context since $z\approx 4$, including a physically-motivated model for radial transport of gas and stars within galactic discs. This expansion…

Astrophysics of Galaxies · Physics 2019-06-19 John C. Forbes , Mark R. Krumholz , Joshua S. Speagle

In this study it is shown that the Tsallis q-extended statistical theory was found efficient to describe faithfully the space plasmas statistics in every case, from the planetic magnetospheres, to solar corona and solar dynamics, as well as…

Chaotic Dynamics · Physics 2012-03-20 G. P. Pavlos

We have recently demonstrated that by expanding in small distance from the magnetic axis compared to the major radius, stellarator shapes with low neoclassical transport can be generated efficiently. To extend the utility of this new design…

Plasma Physics · Physics 2020-10-28 Matt Landreman , Rogerio Jorge

This paper is concerned with the kinetic treatment of quasi-stationary axisymmetric collisionless accretion disc plasmas. The conditions of validity of the kinetic description for non-relativistic magnetized and gravitationally-bound…

High Energy Astrophysical Phenomena · Physics 2023-06-29 Claudio Cremaschini , Massimo Tessarotto

Accurate control of quantum systems requires precise measurement of the parameters that govern the dynamics, including control fields and interactions with the environment. Parameters will drift in time and experiments interleave protocols…

Quantum Physics · Physics 2020-02-11 Swarnadeep Majumder , Leonardo Andreta de Castro , Kenneth R. Brown

A simplified analytical form of the on-axis magnetic well and Mercier's criterion for interchange instabilities for arbitrary three-dimensional magnetic field geometries is derived. For this purpose, a near-axis expansion based on a direct…

Plasma Physics · Physics 2021-05-12 Patrick Kim , Rogerio Jorge , William Dorland