Results 61 to 70 of about 10,224 (240)

Intrinsic Turbulence Stabilization in a Stellarator

Physical Review X, 2016
The magnetic surfaces of modern stellarators are characterized by complex, carefully optimized shaping and exhibit locally compressed regions of strong turbulence drive.
P. Xanthopoulos, G. G. Plunk, A. Zocco, P. Helander   +3 more
doaj   +1 more source

Newtonian stellar models [PDF]

Annals of Physics, 2003
36 pages, LaTex, 14 figures (compressed), uses ...
Heinzle, J. Mark, Uggla, Claes
openaire   +3 more sources

Finite-β turbulence in Wendelstein 7-X enhanced by sub-threshold kinetic ballooning modes

Nuclear Fusion
Magnetic fluctuations affecting turbulence and transport, which are manifest at finite normalized plasma pressure β , pose a significant challenge to magnetic confinement fusion devices aiming to achieve high performance.
P. Mulholland, M.J. Pueschel, J.H.E. Proll, K. Aleynikova, B.J. Faber, P.W. Terry, C.C. Hegna, C. Nührenberg   +7 more
doaj   +1 more source

Collisionless microinstabilities in stellarators I - analytical theory of trapped-particle modes

, 2013
This is the first of two papers about collisionless, electrostatic micro-instabilities in stellarators, with an emphasis on trapped-particle modes. It is found that, in so-called maximum-$J$ configurations, trapped-particle instabilities are absent in ...
Helander, P., Plunk, G. G., Proll, J. H. E.   +2 more
core   +1 more source

Reactor-scale stellarators with force and torque minimized dipole coils

Nuclear Fusion
In this work, we utilize new coil objectives for stellarator optimization with autodifferentiation, including pointwise and net coil–coil forces and torques. We use these methods to perform the first large-scale optimization of planar dipole coil arrays,
Alan A. Kaptanoglu, Alexander Wiedman, Jacob Halpern, Siena Hurwitz, Elizabeth J. Paul, Matt Landreman   +5 more
doaj   +1 more source

Instabilities and turbulence in stellarators from the perspective of global codes

Nuclear Fusion, 2023
In this work, a comparison of the global gyrokinetic codes EUTERPE and GENE-3D in stellarator configurations of the Large Helical Device (LHD) and the Wendelstein 7-X (W7-X) is carried out.
E. Sánchez, A. Bañón Navarro, F. Wilms, M. Borchardt, R. Kleiber, F. Jenko   +5 more
doaj   +1 more source

Reduced electrostatic turbulence in the quasi-isodynamic stellarator configuration CIEMAT-QI4

Nuclear Fusion
CIEMAT-QI4 is a quasi-isodynamic stellarator configuration that simultaneously features very good fast-ion confinement in a broad range of β values, low neoclassical transport and bootstrap current, and ideal magnetohydrodynamic stability up to $\beta ...
J.M. García-Regaña, I. Calvo, E. Sánchez, H. Thienpondt, J.L. Velasco, J.A. Capitán   +5 more
doaj   +1 more source

Model for second harmonic ECRH plasma start-up in stellarators

Nuclear Fusion
Plasma ionisation avalanche under constant electric field is well described by classical theory. It is the standard tokamak start-up method. In this work, we investigate an analogous avalanche process driven by electron cyclotron resonance (ECR). This is
C. Albert Johansson, Pavel Aleynikov, Alvaro Cappa, the W7-X Team   +3 more
doaj   +1 more source

Filament simulations for stellarators; a review of recent progress

Frontiers in Physics
A review of recent advances in simulations of turbulent filaments with relevance to stellarators is presented. Progress in performing global edge turbulence simulations is discussed as well as results from seeded filament simulations with applications to
Brendan Shanahan
doaj   +1 more source

Strong ExB shear flows in the pedestal region in H-mode plasma

, 2006
We report the first experimental observation of stationary zonal flows in the pedestal region of the H-mode plasma in the H-1 toroidal heliac. Strong peaks in E_r shear mark the top and foot of the density pedestal.
A. M. Balk, H. Punzmann, H. Xia, M. G. Shats, S. M. Hamberger   +4 more
core   +1 more source