Results 1 to 10 of about 3,977 (219)

First experimental observation of zonal flows in the optimized stellarator Wendelstein 7-X

Physical Review Research
In this work, we present the first experimental evidence of the presence of zonal flow (ZF) structures in the optimized stellarator Wendelstein 7-X.
D. Carralero, T. Estrada, J. M. García-Regaña, E. Sánchez, T. Windisch, A. Alonso, E. Maragkoudakis, C. Brandt, K. J. Brunner, C. Gallego-Castillo, P. Kornejew, K. Parks, K. Rahbarnia, H. Thienpondt   +13 more
doaj   +2 more sources

A neural network-based method for input parameter optimization of edge transport modeling utilizing experimental diagnostics

Nuclear Fusion
A neural network-based method is developed to fast optimize EMC3-EIRENE input parameters, enabling EMC3-EIRENE to produce synthetic data that closely match experimental measurements on Wendelstein 7-X.
Y. Luo, S. Xu, Y. Liang, E. Wang, J. Cai, Y. Feng, D. Reiter, A. Knieps, S. Brezinsek, D. Harting, M. Krychowiak, D. Gradic, P. Ren, D. Zhang, Y. Gao, G. Fuchert, A. Pandey, M. Jakubowski, the W7-X Team   +18 more
doaj   +1 more source

Modelling of ICRH slow wave propagation and absorption in Wendelstein 7-X stellarator

Nuclear Fusion
The propagation and absorption of the slow waves (SWs) in the three-ion plasma of the Wendelstein 7-X stellarator have been investigated by ray tracing.
D. Grekov, C. Albert, Yu. Turkin, Yu. Volkova   +3 more
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Experimental investigation of the ECRH stray radiation during the start-up phase in Wendelstein 7-X

EPJ Web of Conferences, 2017
Electron cyclotron resonance heating (ECRH) is the main heating mechanism in the Wendelstein 7-X stellarator (W7-X). W7-X is equipped with five absolutely calibrated sniffer probes that are installed in each of the five modules of the device. The sniffer
Moseev Dmitry, Laqua Heinrich, Marsen Stefan, Stange Torsten, Braune Harald, Erckmann Volker, Gellert Florian, Oosterbeek Johann Wilhelm, Wenzel Uwe   +8 more
doaj   +1 more source

Impurity leakage mechanisms in the Wendelstein 7-X island divertor under friction-dominated conditions

Nuclear Fusion
The EMC3-Eirene code was used to study the main impurity leakage mechanism for the island divertor in the standard magnetic field configuration. It was found that under experimentally accessible plasma scenarios in the last experimental campaign, the ...
V.R. Winters, F. Reimold, Y. Feng, V. Perseo, M. Beurskens, S. Bozhenkov, K.J. Brunner, G. Fuchert, R. Koenig, J. Knauer, M. Krychowiak, E. Pasch, E. Scott, D. Zhang, the W7-X Team   +14 more
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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

Particle transport in reduced turbulence neutral beam heated discharges at Wendelstein 7-X

Nuclear Fusion
A spontaneous reduction in anomalous particle transport in the plasma core is seen experimentally in reproducible, purely neutral beam heated plasma phases at Wendelstein 7-X (W7-X).
S. Bannmann, O. Ford, P.Zs. Poloskei, J. Svensson, A. Pavone, S. Kwak, U. Hoefel, E. Pasch, G. Fuchert, H.M. Smith, S. Lazerson, P. McNeely, N. Rust, D. Hartmann, R.C. Wolf, the W7-X Team   +15 more
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Neural network-based surrogate model for 3D edge-plasma transport in the standard configuration of W7-X

Nuclear Fusion
This paper presents a neural‐network surrogate model for Wendelstein 7-X (W7-X) edge transport simulations, trained on an EMC3-EIRENE dataset that spans nearly the entire operating-parameter space currently explored in the W7-X standard configuration ...
Y. Luo, S. Xu, Y. Liang, E. Wang, J. Cai, A. Knieps, R. Pei, M. Tan, Y. Feng, D. Reiter, S. Brezinsek, D. Harting, M. Krychowiak, D. Gradic, M. Jakubowski, the W7-X Team   +15 more
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Erratum: Confirmation of the topology of the Wendelstein 7-X magnetic field to better than 1:100,000. [PDF]

Nat Commun, 2017
Pedersen TS, Otte M, Lazerson S, Helander P, Bozhenkov S, Biedermann C, Klinger T, Wolf RC, Bosch HS, Wendelstein 7-X Team.   +9 more
europepmc   +1 more source

Design and experimental verification of a multi-pass ECRH plasma start-up scenario at a reduced magnetic field of 1.8 T at W7-X

Nuclear Fusion
Wendelstein 7-X (W7-X) nominally operates at a magnetic field of 2.5 T, but operation at a lower magnetic field strength is desired. The electron cyclotron resonance heating (ECRH) system of W7-X operates at 140 GHz, corresponding to second harmonic (X2)
Niklas Simon Polei, Torsten Stange, Kai Jakob Brunner, Olaf Grulke, Juan Fernando Guerrero Arnaiz, Laurent Krier, Heinrich Peter Laqua, Stefan Marsen, Dmitry Moseev, Burkhard Plaum, Sergiy Ponomarenko, Kian Rahbarnia, Georg Schlisio, Jonas Zimmermann, W7X-Team   +14 more
doaj   +1 more source