Results 1 to 10 of about 10,277 (144)
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 +9 more
doaj +2 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 +5 more
doaj +1 more source
Kinetic simulations of scrape-off layer physics in the DIII-D tokamak
Nuclear Materials and Energy, 2017 Simulations using the fully kinetic code XGCa were undertaken to explore the impact of kinetic effects on scrape-off layer (SOL) physics in DIII-D H-mode plasmas.
R.M. Churchill +7 more
doaj +1 more source
Gyrokinetic studies of the effect of beta on drift-wave stability in NCSX [PDF]
, 2012 The gyrokinetic turbulence code GS2 was used to investigate the effects of plasma beta on linear, collisionless ion temperature gradient (ITG) modes and trapped electron modes (TEM) in National Compact Stellarator Experiment (NCSX) geometry.
Baumgaertel, J. A. +4 more
core +3 more sources
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 +5 more
doaj +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 +2 more
doaj +1 more source
Collisionless microinstabilities in stellarators II - numerical simulations [PDF]
, 2013 Microinstabilities exhibit a rich variety of behavior in stellarators due to the many degrees of freedom in the magnetic geometry. It has recently been found that certain stellarators (quasi-isodynamic ones with maximum-$J$ geometry) are partly resilient
Helander, P. +2 more
core +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. +6 more
core +2 more sources
Nuclear Materials and Energy, 2019 In ASDEX Upgrade with full-tungsten wall, boronization is an important tool to control tungsten sources and allow reliable operation at low collisionality. The duration of the beneficial effects is limited by the erosion of the boron layer, in particular
A. Bortolon +12 more
doaj +1 more source
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 +4 more
core +2 more sources