Speaker
Fabrice Louche
(Plasma Physics Laboratory)
Description
Ion cyclotron wall conditioning (ICWC) is being developed for ITER as a baseline conditioning technique in which the ion cyclotron heating and current drive system will be employed to produce and sustain the current-less conditioning plasma. The TOMAS project (TOroidal MAgnetized System, operated at the FZ-Juelich, Germany) proposes to explore several key aspects of ICWC. This project stands on two pillars featuring plasma and material studies:
(a) plasma-induced material modification and optimization of the wall conditioning efficiency via exposure of probes made of real PFC and the use of tracers;
(b) detailed research on ICWC plasma production and optimisation to benchmark codes.
The ICRF system requirements to fulfill the above aims are:
(a) ability to couple op to 6 kW of RF power to low density and low temperature plasma (101111/cm33, 3-10 eV)
(b) ability to initiate plasma in broad frequency range (15 to 45MHz) for plasma production studies.
For this purpose we have designed an ICRF system made of a single strap antenna within a metallic box, connected to a feeding port and a pre-matching system. We discuss the design work of the antenna system with the help of the commercial electromagnetic software CST Microwave Studio. The simulation results for a given geometry provide input impedance matrices for the two-port system. These matrices are afterwards inserted into various circuit models to assess the accessibility of the required frequency range.
The sensitivity of the matching system to uncertainties on plasma loading and capacitance values is notably addressed. With a choice of three variable capacitors we show that the system becomes resilient to such uncertainties. We also demonstrate that the system can cope as well with the high reflected power levels during the short breakdown phase of the RF discharge.
Co-authors
Anatoli Lyssoivan
(Plasma Physics Laboratory, ERM/KMS, 30, Avenue de la Renaissance - 1000 Brussels, Belgium)
Andre Messiaen
(Plasma Physics Laboratory, ERM/KMS, 30, Avenue de la Renaissance - 1000 Brussels, Belgium)
Andrey Litnovsky
(Institut für Energie und Klimaforschung/Plasmaphysik (IEK-4), Forschungszentrum Jülich (TEC Partner), D-52435 Jülich, Germany)
Christian Linsmeier
(Institut für Energie und Klimaforschung/Plasmaphysik (IEK-4), Forschungszentrum Jülich (TEC Partner), D-52435 Jülich, Germany)
Fabrice Louche
(Plasma Physics Laboratory, ERM/KMS, 30, Avenue de la Renaissance - 1000 Brussels, Belgium)
Frederic Durodie
(Plasma Physics Laboratory, ERM/KMS, 30, Avenue de la Renaissance - 1000 Brussels, Belgium)
Jozef Ongena
(Plasma Physics Laboratory, ERM/KMS, 30, Avenue de la Renaissance - 1000 Brussels, Belgium)
Marek Rubel
(Department of Fusion Plasma Physics, Royal Institute of Technology (KTH), Association VR, 100 44 Stockholm, Sweden)
Matej Tripski
(Plasma Physics Laboratory, ERM/KMS, 30, Avenue de la Renaissance - 1000 Brussels, Belgium)
Michael Van Schoor
(Plasma Physics Laboratory, ERM/KMS, 30, Avenue de la Renaissance - 1000 Brussels, Belgium)
Per Peterson
(Department of Fusion Plasma Physics, Royal Institute of Technology (KTH), Association VR, 100 44 Stockholm, Sweden)
Riccardo Ragona
(Plasma Physics Laboratory, ERM/KMS, 30, Avenue de la Renaissance - 1000 Brussels, Belgium)
Sebastijan Brezinsek
(Institut für Energie und Klimaforschung/Plasmaphysik (IEK-4), Forschungszentrum Jülich (TEC Partner), D-52435 Jülich, Germany)
Soren Moller
(Institut für Energie und Klimaforschung/Plasmaphysik (IEK-4), Forschungszentrum Jülich (TEC Partner), D-52435 Jülich, Germany)
Tom Wauters
(Plasma Physics Laboratory, ERM/KMS, 30, Avenue de la Renaissance - 1000 Brussels, Belgium)
