Results 21 to 30 of about 464 (186)

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

open access: yesNuclear 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

Stellar ages from stellar rotation [PDF]

open access: yesProceedings of the International Astronomical Union, 2008
AbstractOur ability to determine stellar ages from measurements of stellar rotation, hinges on how well we can measure the dependence of rotation on age for stars of different masses. Rotation periods for stars in open clusters are essential to determine the relations between stellar age, rotation, and mass.
openaire   +2 more sources

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

open access: yesPhysical 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

Stellar Structure and the Origin of Stellar Energy* [PDF]

open access: yesNature, 1930
THE generally accepted theory of the internal conditions in stars, due to Sir A. S. Eddington, depends largely on a special solution of the fundamental equations, and according to this a definite calculable luminosity is associated with a given mass. If this were the only solution of the equations it would conflict, as I have repeatedly shown in recent
openaire   +2 more sources

Stellar Motions and Stellar Dynamics [PDF]

open access: yesTransactions of the International Astronomical Union, 1962
The texts of the twelve prepared contributions, often in abbreviated form, are given first; they are followed by a summary of the discussion on all the contributions considered together.
A. Blaauw   +8 more
openaire   +1 more source

Real-time wall conditioning by controlled injection of boron and boron nitride powder in full tungsten wall ASDEX Upgrade

open access: yesNuclear 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

Stellar coronae [PDF]

open access: yesSymposium - International Astronomical Union, 1997
The last two decades have seen the emergence of a new field in stellar astrophysics, the study of stellar coronae mostly in X-ray domain. With the advent of soft X-ray imagery X-ray emission was found from many thousands of solar-like stars. I will summarize the most important findings of X-ray surveys of late type stars and put the results in the ...
openaire   +1 more source

Overdense plasma heating in Wendelstein 7-X(W7-X) stellarator

open access: yesResults in Physics, 2017
High yield nuclear fusion operating in tokamak and stellarator need to heat plasma up to the required temperatures. As the confined plasma is overdensed, the electron cyclotron resonance heating (ECRH) is inefficient due to cut-off layer.
S. Adlparvar   +3 more
doaj   +1 more source

Energetic particle optimization of quasi-axisymmetric stellarator equilibria

open access: yesNuclear 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   +6 more
doaj   +1 more source

Stellarators

open access: yesFusion Science and Technology, 2004
Stellarators are toroidal devices where the required rotational transform of the magnetic field lines is generated by external field coils and not via an induced net toroidal plasma current. This confinement scheme has the advantages that, in principle, steady-state plasma operation is possible and that it does not have to brace itself against ...
openaire   +6 more sources

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