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Title: Observation of plasma instabilities related to dust particle growth mechanisms in electron cyclotron resonance plasmas

Instabilities are observed in the self-bias voltage measured on a probe immersed in microwave plasma excited at Electron Cyclotron Resonance (ECR). Observed in the MHz range, they were systematically measured in dust-free or dusty plasmas (obtained for different conditions of applied microwave powers and acetylene flow rates). Two characteristic frequencies, well described as lower hybrid oscillations, can be defined. The first one, in the 60–70 MHz range, appears as a sharp peak in the frequency spectra and is observed in every case. Attributed to ions, its position shift observed with the output power highlights that nucleation process takes place in the dusty plasma. Attributed to lower hybrid oscillation of powders, the second broad peak in the 10–20 MHz range leads to the characterization of dust particles growth mechanisms: in the same way as in capacitively coupled plasmas, accumulation of nucleus confined near the probe in the magnetic field followed by aggregation takes place. Then, the measure of electrical instabilities on the self-bias voltage allows characterizing the discharge as well as the chemical processes that take place in the magnetic field region and their kinetics.
Authors:
 [1] ;  [2] ; ;  [3] ;  [1] ;  [4]
  1. Jožef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia)
  2. (France)
  3. CNRS, LAPLACE, 31062 Toulouse/Université de Toulouse, UPS, INPT, LAPLACE, 118 rte de Narbonne, 31062 Toulouse Cedex 9 (France)
  4. Groupe de Physique des Plasmas, Département de Physique, Université de Montréal, CP 6128, Succursale Centre-ville, Montréal, Québec H3C 3J7 (Canada)
Publication Date:
OSTI Identifier:
22218475
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 20; Journal Issue: 10; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ACETYLENE; AGGLOMERATION; DUSTS; ECR HEATING; ELECTRIC POTENTIAL; ELECTRON CYCLOTRON-RESONANCE; FLOW RATE; HIGH-FREQUENCY DISCHARGES; LOWER HYBRID CURRENT DRIVE; LOWER HYBRID HEATING; MAGNETIC FIELDS; MHZ RANGE; MICROWAVE RADIATION; NUCLEATION; OSCILLATIONS; PLASMA INSTABILITY; PLASMA WAVES