Studies of RF sheaths and diagnostics on IShTAR

Journal Article · Thu Dec 10 00:00:00 EST 2015 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.4936471· OSTI ID:22496184

Devaux, S.; Faudot, E.; Heuraux, S.; Moritz, J. ^[1]; D’Inca, R.; Faugel, H.; Fünfgelder, H.; Jacquot, J.; Ochoukov, R. ^[2]; Louche, F.; Tripsky, M.; Van Eester, D.; Wauters, T. ^[3]; Noterdaeme, J. -M. ^[4]

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1. YIJL, UMR7198 CNRS-Université de Lorraine, Nancy (France)
2. Max-Planck-Institut für Plasmaphysik, Garching (Germany)
3. LPP-ERM/KMS, Royal Military Academy, Brussels (Belgium)
4. Department of Applied Physics, Ghent University, Ghent (Belgium)

IShTAR (Ion cyclotron Sheath Test ARrangement) is a linear magnetised plasma test facility for RF sheaths studies at the Max-Planck-Institut für Plasmaphysik in Garching. In contrast to a tokamak, a test stand provides more liberty to impose the parameters and gives better access for the instrumentation and antennas. The project will support the development of diagnostic methods for characterising RF sheaths and validate and improve theoretical predictions. The cylindrical vacuum vessel has a diameter of 1 m and is 1.1 m long. The plasma is created by an external cylindrical plasma source equipped with a helical antenna that has been designed to excite the m=1 helicon mode. In inductive mode, plasma densities and electron temperatures have been characterised with a planar Langmuir probe as a function of gas pressure and input RF power. A 2D array of RF compensated Langmuir probes and a spectrometer are planned. A single strap RF antenna has been designed; the plasma-facing surface is aligned to the cylindrical plasma to ease the modelling. The probes will allow direct measurements of plasma density profiles in front of the RF antenna, and thus a detailed study of the density modifications induced by RF sheaths, which influences the coupling. The RF antenna frequency has been chosen to study different plasma wave interactions: the accessible plasma density range includes an evanescent and propagative behaviour of slow or fast waves, and allows the study of the effect of the lower hybrid resonance layer.

• OSTI ID: 22496184
• Journal Information: AIP Conference Proceedings, Vol. 1689, Issue 1; Conference: 21. topical conference on radio frequency power in plasmas, Lake Arrowhead, CA (United States), 27-29 Apr 2015; Other Information: (c) 2015 EURATOM; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ANTENNAS
CYCLOTRONS
CYLINDRICAL CONFIGURATION
DIAGNOSTIC TECHNIQUES
ELECTRON TEMPERATURE
FIRST WALL
ION CYCLOTRON-RESONANCE
LANGMUIR PROBE
LOWER HYBRID CURRENT DRIVE
LOWER HYBRID HEATING
PLASMA DENSITY
PLASMA WAVES
RF SYSTEMS
SIMULATION
SPECTROMETERS
TEST FACILITIES
TOKAMAK DEVICES