Results 51 to 60 of about 2,047 (170)

Dynamics of zonal flow-like structures in the edge of the TJ-II stellarator

, 2012
The dynamics of fluctuating electric field structures in the edge of the TJ-II stellarator, that display zonal flow-like traits, is studied. These structures have been shown to be global and affect particle transport dynamically [J.A. Alonso et al., Nucl.
Alonso J, B Ph Van Milligen, C Hidalgo, C Silva, D Carralero, Helander P, Hidalgo C, J A Alonso, J Arévalo, J L Velasco, M A Pedrosa, Motojima O, Pedrosa M A, Scott B, Tala T, Velasco J, Velasco J, Velasco J L Arévalo J Alonso J A, Wobig H, Wobig H, Xu Y   +20 more
core   +1 more source

Gaussian process tomography for soft x-ray spectroscopy at WEST without equilibrium information [PDF]

, 2018
International audienceGaussian process tomography (GPT) is a recently developed tomography method based on the Bayesian probability theory [J. Svensson, JET Internal Report EFDA-JET-PR(11)24, 2011 and Li et al., Rev. Sci. Instrum. 84, 083506 (2013)].
Jardin, A., Li, D., Mazon, D., Svensson, J., Verdoolaege, Geert, Wang, TianBo   +5 more
core   +3 more sources

Design of 3D equilibria and coils for steady-state operation of tokamaks

Nuclear Fusion
Inspired by the respective advantages of tokamaks and stellarators, we propose a quasi-axisymmetric (QA) tokamak-stellarator hybrid concept as a steady-state operation mode of standard tokamaks.
Yihui Liang, Yao Zhou, Fanghao Dong, Caoxiang Zhu, Guodong Yu, Yuansheng Zhao, Ge Dong   +6 more
doaj   +1 more source

Oscillatory relaxation of zonal flows in a multi-species stellarator plasma

, 2018
The low frequency oscillatory relaxation of zonal potential perturbations is studied numerically in the TJ-II stellarator (where it was experimentally detected for the first time).
Alonso, A., Calvo, I., Kleiber, R., Medina, F., Monreal, P., Sánchez, E., team, the TJ-II, Velasco, J. L.   +7 more
core   +1 more source

Optimization of nonlinear turbulence in stellarators

Journal of Plasma Physics
We present new stellarator equilibria that have been optimized for reduced turbulent transport using nonlinear gyrokinetic simulations within the optimization loop. The optimization routine involves coupling the pseudo-spectral GPU-native gyrokinetic codeGXwith the stellarator equilibrium and optimization codeDESC.
Kim, P., Buller, S., Conlin, R., Dorland, W., Dudt, D.W., Gaur, R., Jorge, R., Kolemen, E., Landreman, M., Mandell, N.R., Panici, D.   +10 more
openaire   +2 more sources

Permanent-Magnet Optimization for Stellarators as Sparse Regression

Physical Review Applied, 2022
A common scientific inverse problem is the placement of magnets that produce a desired magnetic field inside a prescribed volume. This is a key component of stellarator design, and recently permanent magnets have been proposed as a potentially useful tool for magnetic field shaping.
Alan A. Kaptanoglu, Tony Qian, Florian Wechsung, Matt Landreman   +3 more
openaire   +2 more sources

Remote-Steering Antennas for 140 GHz Electron Cyclotron Heating of the Stellarator W7-X

EPJ Web of Conferences, 2017
For electron cyclotron resonance heating of the stellarator W7-X at IPP Greifswald, a 140 GHz/10 MW cw millimeter wave system has been built. Two out of 12 launchers will employ a remote-steering design. This paper describes the overall design of the two
Lechte C., Kasparek W., Plaum B., Zeitler A., Erckmann V., Laqua H., Schneider N., Weissgerber M., Bechtold A., Busch M., Szepaniak B.   +10 more
doaj   +1 more source

A new continuous optimization method of standardized cubic permanent magnets for stellarators

Nuclear Fusion
Stellarator configurations can be realized using permanent magnets in combination with tokamak-like planar coils. From the perspective of engineering feasibility and cost-effectiveness, using standardized cubic permanent magnets with a finite number of ...
Xiangyu Zhang, Dehong Chen, Guosheng Xu, Zhiyuan Lu, Caoxiang Zhu, Liang Chen, Minyou Ye, Baonian Wan   +7 more
doaj   +1 more source

Electromagnetic coil optimization for reduced Lorentz forces

Nuclear Fusion
The reduction of magnetic forces on electromagnetic coils is an important consideration in the design of high-field devices such as the stellarator or tokamak.
Siena Hurwitz, Matt Landreman, Paul Huslage, Alan Kaptanoglu   +3 more
doaj   +1 more source

Stochastic diffusion of energetic ions in optimized stellarators [PDF]

Physics of Plasmas, 2001
It is shown that the collisionless transformation of locally trapped and passing particle orbits in the optimized stellarators of the Wendelstein line results in stochastic diffusion of energetic ions. This diffusion can lead to the loss of a significant fraction of the energetic ion population from the region where the characteristic diffusion time is
Beidler, C., Kolesnichenko, Y., Marchenko, V., Sidorenko, I., Wobig, H.   +4 more
openaire   +2 more sources