Speaker
Dr
Matthias Hirsch
(Max-Planck-Institut für Plasmaphysik)
Description
Wendelstein 7-X (W7-X) is built to assess the concept of optimized stellarators at reactor-relevant values of both collisionality and the plasma beta.
In its first operation phase (started in the end of 2015 for 10 weeks of plasma experiments), the device is equipped with five uncooled, inboard carbon limiters. This phase of the project is dedicated to integrated operation, commissioning and tests of components, diagnostics and device control performed under plasma conditions. In addition a physics program has been conducted as far as the machine conditions allowed.
The experimental program started with the optimization of the ECH induced plasma break-down. Sequences of ECH pulses have been performed for wall conditioning as well as helium glow discharge conditioning (in periods without magnetic field). The device is operated with helium and hydrogen gas puffs but yet without feedback density control. Pulses are limited by technical margins and machine capabilities. For example the discharge length is restricted by the maximum allowed energy for a single discharge which has been set to 4 MJ per pulse to avoid uncontrolled overheating of unprotected in-vessel components.
At the time this abstract is being prepared, stationary discharges over 6s have been achieved, however, due to the decribed energy limit with reduced heating power. High performance discharges with 4 MW heating power and an overall duration of around a second reach stationary electron temperature profiles with about 8 keV in the core surrounded by steep temperature gradients at around half minor radius. The density ramped up in successive gas pulses reaches ~2.5 1019 m-3; beyond that the discharges degrade and are terminated by radiation. The central ion temperature increases continuously unto the discharge end due to the increasing electron ion coupling and reached up to 2 keV in the best cases.
The paper gives an overview of the energy and particle confinement in the first phase of W7-X in line with findings on transport.
| Country or International Organization | Germany |
|---|---|
| Paper Number | EX/4-5 |
Primary author
Dr
Matthias Hirsch
(Max-Planck-Institut für Plasmaphysik)
Co-authors
Dr
Agata Czarnecka
(IPPLM, Warsaw, Poland)
Dr
Andreas Dinklage
(Max-Planck-Institut für Plasmaphysik)
Dr
Andreas Krämer-Flecken
(Forschungszentrum Jülich)
Dr
Andreas Langenberg
(Max-Planck-Institut für Plasmaphysik,17491 Greifswald, Germany)
Dr
Andreas Werner
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Arturo Alonso
(Laboratorio Nacional de Fusión - CIEMAT)
Dr
Birger Buttenschön
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Christoph Biedermann
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Craig Beidler
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Daihong Zhang
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Dirk Hartmann
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Dirk Naujoks
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Dmitry Moseev
(Max-Planck-Institut für Plasmaphysik)
Dr
Ekkehard Pasch
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Emilio Blanco
(CIEMAT)
Dr
Fabio Pisano
(University of Cagliari, Cagliari, Italy)
Dr
Gabor Kocsis
(Wigner Institute, Budapest, Hungary)
Dr
Glen Wurden
(LANL)
Dr
Golo Fuchert
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Hans-Stephan Bosch
(Max-Planck-Institute for Plasma Physics)
Dr
Hayato Tsuchiya
(National Institute for Fusion Science, Toki, Japan)
Dr
Heinrich Laqua
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Henning Maaßberg
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Henning Thomsen
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Mr
Humberto Trimino-Mora
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Irek Ksiazek
(Opole University, Opole, Poland)
Dr
Jeff Harris
(Oak Ridge National Laboratory, Oak Ridge, TN, USA)
Dr
Jens Knauer
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Joachim Geiger
(Max-Planck-Institute for Plasma Physics, Greifswald, Germany)
Dr
Jürgen Baldzuhn
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Kian Rahbarnia
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Mrs
Laurie Stephey
(University of Wisconsin, Madison, WI, USA)
Dr
Maciej Krychowiak
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Maia Kubkowska
(IPPLM, Warsaw, Poland)
Dr
Marc Beurskens
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Marcin Jakubowski
(Max-Planck-Institut für Plasmaphysik)
Dr
Matthias Otte
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Michael Endler
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Natalia Krawczyk
(IPPLM, Warsaw, Poland)
Dr
Nikolai Marushchenko
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Novimir Pablant
(Princeton Plasma Physics Laboratory)
Prof.
Olaf Grulke
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Petra Kornejew
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Rainer Burhenn
(emilio.blanco@ciemat.es)
Dr
Ralf König
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Prof.
Robert Wolf
(Max-Planck-Institute for Plasma Physics)
Dr
Rudolf Brakel
(emilio.blanco@ciemat.es)
Dr
Samuel Lazerson
(Princeton Plasma Physics Laboratory)
Dr
Sergey Bozhenkov
(Max-Planck Insitute of Plasma Physics)
Dr
Stefan Marsen
(Max-Planck-Institut für Plasmaphysik Teilinstitut Greifswald)
Dr
Sören Klose
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Tamara Andreeva
(Max-Planck-Institut für Plasmaphysik, Teilinstitut Greifswald, Germany)
Dr
Tamas Szepesi
(Wigner Institute, Budapest, Hungary)
Dr
Teresa Estrada
(CIEMAT)
Prof.
Thomas Klinger
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Prof.
Thomas Sunn-Pedersen
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Timo Schröder
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Tom Wauters
(Laboratory for Plasma Physics - ERM/KMS, 1000 Brussels, Belgium, TEC Partner)
Dr
Tomasz Fornal
(IPPLM, Warsaw, Poland)
Dr
Torsten Stange
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Mr
Udo Höfel
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Uwe Wenzel
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Victor Moncada
(CEA, France)
Dr
Yuri Turkin
(Max-Planck-Institut für Plasmaphysik, Greifswald, Germany)
Dr
Álvaro Cappa
(Laboratorio Nacional de Fusión CIEMAT)
