Carbon Dust Growth in a Radiofrequency Discharge

Journal Article · Wed Mar 19 00:00:00 EDT 2008 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2909165· OSTI ID:21136958

Peng, Y; Hugon, R; Brochard, F; Vasseur, J -L; Bougdira, J ^[1]; Lacroix, D ^[2]; Brosset, C ^[3]

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1. LPMIA, UMR CNRS 7040-Nancy Universite-Faculte des Sciences et Techniques-B.P. 239-54506 Vandoeuvre les Nancy Cedex (France)
2. LEMTA, UMR CNRS 7563-Nancy Universite-Faculte des Sciences et Techniques-B.P. 239--54506 Vandoeuvre les Nancy Cedex (France)
3. CEA/DSM/DRFC, 10108 Saint Paul lez Durance (France)

Plasma wall interactions studies are of primary importance for increasing the life time of the first wall in fusion devices. In ITER, the divertor target plates will receive on a small surface a significant part of the power during operation, and carbon materials will be used. Although carbon has several advantages than the materials used at other places of the plasma chamber (W and Be), they undergo chemical reactions with hydrogen and its isotopes used as fuel for the fusion reaction. Under ITER operating conditions, the high temperature of the wall will promote diffusion and recombination of atomic hydrogen, withholding the fuel. Moreover, carbon atoms produced by erosion may be deposited at other locations, causing further increase of the hydrogen inventory in the vessel, and encountering several subsequent major safety issues.In our experiment, carbon dust formation and growth are studied in a radiofrequency discharge. Dust particles sediment into the cathode sheath using carbon originating either from a graphite cathode in pure argon plasmas or from C{sub 2}H{sub 2} mixed with argon in case where a stainless steel cathode is used. In this contribution, we present a characterization of carbon dust particles under various plasma conditions (pressure, RF power, C{sub 2}H{sub 2} percentage). Dust growth is studied in situ using FTIR spectroscopy, whereas the structural properties of the dust particles are studied ex situ using TEM, SEM, and FTIR.

• OSTI ID: 21136958
• Journal Information: AIP Conference Proceedings, Vol. 993, Issue 1; Conference: PLASMA 2007: International conference on research and applications of plasmas; 4. German-Polish conference on plasma diagnostics for fusion and applications; 6. French-Polish seminar on thermal plasma in space and laboratory, Greifswald (Germany), 16-19 Oct 2007; Other Information: DOI: 10.1063/1.2909165; (c) 2008 American Institute of Physics; 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
ARGON
CATHODES
CONTAINERS
DIFFUSION
DIVERTORS
DUSTS
EROSION
FIRST WALL
FOURIER TRANSFORMATION
GRAPHITE
HIGH-FREQUENCY DISCHARGES
HYDROGEN
INFRARED SPECTRA
ITER TOKAMAK
PLASMA
SCANNING ELECTRON MICROSCOPY
STAINLESS STEELS
TRANSMISSION ELECTRON MICROSCOPY
WALL EFFECTS