Results 1 to 10 of about 2,075 (173)

Confirmation of the topology of the Wendelstein 7-X magnetic field to better than 1:100,000 [PDF]

Nature Communications, 2016
Early stellarator designs suffered from high particle losses, an issue that can be addressed by optimization of the coils. Here the authors measure the magnetic field lines in the Wendelstein 7-X stellarator, confirming that the complicated design of the
T. Sunn Pedersen, M. Otte, S. Lazerson, P. Helander, S. Bozhenkov, C. Biedermann, T. Klinger, R. C. Wolf, H. -S. Bosch, The Wendelstein 7-X Team   +9 more
doaj   +4 more sources

Critical gradient turbulence optimization toward a compact stellarator reactor concept

Physical Review Research, 2023
Integrating turbulence into stellarator optimization is achieved by targeting the onset for the ion-temperature-gradient mode, highlighting effects of field line curvature, parallel connection length, local magnetic shear, and flux surface expansion. The
G. T. Roberg-Clark, G. G. Plunk, P. Xanthopoulos, C. Nührenberg, S. A. Henneberg, H. M. Smith   +5 more
doaj   +2 more sources

A promising approach to steady-state fusion: High-temperature superconducting strong-field stellarator with precise omnigenity [PDF]

The Innovation
The stellarator has inherent advantages over the tokamak in achieving steady-state operation, especially due to its absence of disruptions and lack of need for current drive and the associated recirculating power.
Guosheng Xu, Zhiyuan Lu, Dehong Chen, Baonian Wan   +3 more
doaj   +2 more sources

Uncertainty quantification in three‐dimensional magnetohydrodynamic equilibrium reconstruction via surrogate‐assisted Bayesian inference

Contributions to Plasma Physics, Volume 63, Issue 5-6, June-July 2023., 2023
Abstract In three‐dimensional (3D) equilibrium, reconstruction defining parameters of an ideal magneto‐hydrodynamic equilibrium are inferred from a set of plasma diagnostic measurements. For the reconstructed parameters, various forms of uncertainty estimates exist within common 3D reconstruction frameworks.
Robert Köberl, Udo von Toussaint, Hans‐Joachim Bungartz, Jonathan Schilling, Christopher G. Albert, W7‐X Team   +5 more
wiley   +1 more source

Coarse-grained gyrokinetics for the critical ion temperature gradient in stellarators

Physical Review Research, 2022
We present a modified gyrokinetic theory to predict the critical gradient that determines the linear onset of the ion temperature gradient (ITG) mode in stellarator plasmas.
G. T. Roberg-Clark, G. G. Plunk, P. Xanthopoulos   +2 more
doaj   +1 more source

Physics-regularized neural network of the ideal-MHD solution operator in Wendelstein 7-X configurations

Nuclear Fusion, 2023
The computational cost of constructing 3D magnetohydrodynamic (MHD) equilibria is one of the limiting factors in stellarator research and design. Although data-driven approaches have been proposed to provide fast 3D MHD equilibria, the accuracy with ...
Andrea Merlo, Daniel Böckenhoff, Jonathan Schilling, Samuel Aaron Lazerson, Thomas Sunn Pedersen, the W7-X Team   +5 more
doaj   +1 more source

Energetic particle optimization of quasi-axisymmetric stellarator equilibria

Nuclear Fusion, 2022
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 work, a fixed-boundary stellarator equilibrium was re-optimized for
Alexandra LeViness, John C. Schmitt, Samuel A. Lazerson, Aaron Bader, Benjamin J. Faber, Kenneth C. Hammond, David A. Gates   +6 more
doaj   +1 more source

Properties of a new quasi-axisymmetric configuration [PDF]

, 2018
A novel, compact, quasi-axisymmetric configuration is presented which exhibits low fast-particle losses and is stable to ideal MHD instabilities. The design has fast-particle loss rates below 8\% for flux surfaces within the half-radius, and is shown to ...
Beidler, C. D., Drevlak, M., Helander, P., Henneberg, S. A., Loizu, J., Nührenberg, C., Turkin, Y.   +6 more
core   +2 more sources

Optimization of flux-surface density variation in stellarator plasmas with respect to the transport of collisional impurities [PDF]

, 2019
Avoiding impurity accumulation is a requirement for steady-state stellarator operation. The accumulation of impurities can be heavily affected by variations in their density on the flux-surface.
Buller, Stefan, Mollén, Albert, Newton, Sarah Louise, Pusztai, Istvan, Smith, Håkan M.   +4 more
core   +2 more sources

Integration of kinetic ions in a three‐dimensional Monte‐Carlo neutral transport code

Contributions to Plasma Physics, Volume 60, Issue 5-6, June-July 2020., 2020
Abstract Charged particles of species different from the major constituents of a plasma might not reach local thermodynamic equilibrium during their lifespan. Such low collisional ions render the often‐used fluid description, assuming Maxwellian velocity distribution, as insufficient. Hence, kinetic treatment of such minorities becomes inevitable.
Friedrich Schluck
wiley   +1 more source