Laser-induced-fluorescence observation of ion velocity distribution functions in a plasma sheath
- Equipe Turbulence Plasma, LPIIM, CNRS-Universite de Provence, Marseille (France)
Experimental results obtained by laser-induced-fluorescence on metastable ion velocity distribution functions (MIVDF) in electrostatic presheaths and sheaths in argon plasmas produced by the thermoionic effect in a multipolar dc discharge are presented. The shape of the measured MIVDF are in qualitative agreement, for the presheath, with Emmert's model and exhibit: (1) a Maxwellian profile at the center of the device where the potential is zero; (2) a distribution function's shape made of three distinct parts at the entrance of the presheath. Inside the sheath the recorded MIVDF recovers a Maxwellian profile with a width unexpectedly related to the background neutral pressure. The velocity and potential profiles that can be deduced from the measured MIVDF show a strong influence of the primary electrons emitted by the filaments.
- OSTI ID:
- 20787339
- Journal Information:
- Physics of Plasmas, Vol. 13, Issue 6; Other Information: DOI: 10.1063/1.2206786; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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