Speaker
H. Fuenfgelder
(Max-Planck-Institut für Plasmaphysik)
Description
A enhanced impurity production has often accompanied experiments using ICRF (Ion Cyclotron Range of Frequency) as heating method. Positive effects, such as the capability to deposit the power centrally even at high density and thereby reduce the central impurity accumulation, were wiped out in the all‐metal ASDEX Upgrade when the antenna limiters were also coated with W. The hypothesis that this enhanced interaction is due to RF sheaths – possibly a consequence of currents induced at undesirable locations - has, up to now, not been invalidated.
New 3-strap antennas in ASDEX Upgrade, designed to lower these RF sheaths by cancelling these undesirable currents induced in the antenna frame, have shown experimentally to indeed reduce the impurity production.
The antennas were designed and fabricated in an international cooperation between IPP, ASIPP (Hefei, China) and ENEA (Frascati, Italy) at different sites whereas installation and test was done by a multinational team at IPP.
We report on the points to pay attention to for such international cooperation, on the tools and approaches we used that helped set up a good cooperation, on the final outcome as well as on those aspect we would tackle differently for a similar situation in the future.
The antenna also integrates a powerful reflectometer system, designed and built by ENEA and IST (Portugal) from which the first results are coming in. We elaborate on the concept on the basis of which those antennas were built and present an overview of the results obtained.
1 http://www.euro-fusionscipub.org/mst1
Co-authors
A. A. Tuccillo
(ENEA, Frascati, Italy)
A. Mancini
(ENEA, Frascati, Italy)
A. Silva
(Instituto de Plasmas e Fusão Nuclear, IST, 1037-001 Lisboa, Portugal)
D. Aguiam
(Instituto de Plasmas e Fusão Nuclear, IST, 1037-001 Lisboa, Portugal)
D. Milanesio
(Politecnico de Torino, Torino, Italy)
EUROfusion MST1 Team
(Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85738 Garching, Germany)
G. Rocchi
(ENEA, Frascati, Italy)
H. Faugel
(Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85738 Garching, Germany)
H. Fuenfgelder
(Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85738 Garching, Germany)
I. Zammuto
(Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85738 Garching, Germany)
J.-M. Noterdaeme
(Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85738 Garching, Germany;Ghent University, Applied Physics Department, B-7000 Gent, Belgium)
Jacquot
(Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85738 Garching, Germany)
O. D’Arcangelo
(ENEA, Frascati, Italy)
O. Tudisco
(ENEA, Frascati, Italy)
Q. Yang
(ASIPP, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China)
R. Maggiora
(Politecnico de Torino, Torino, Italy)
R. Ochoukov
(Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85738 Garching, Germany)
T. Vierle
(Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85738 Garching, Germany)
V. V. Bobkov
(Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85738 Garching, Germany)
Y. Chen
(ASIPP, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China)
Y. Wang
(ASIPP, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China)
the ASDEX Upgrade Team
(Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85738 Garching, Germany)
