Hannover 2010 – scientific programme

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P: Fachverband Plasmaphysik

P 18: Poster: Diagnostics

P 18.8: Poster

Thursday, March 11, 2010, 16:00–18:00, Lichthof

Neutral and ion kinetics in a radio-frequency helicon discharge — •Yusuf Celik¹, Dirk Luggenhölscher¹, Mitsutoshi Aramaki², Kohei Ogiwara³, Masayoshi Tanaka⁴, and Uwe Czarnetzki¹ — ¹Institute for Atomic and Plasma Physics, Ruhr-University Bochum, 44780 Germany — ²Department of Electrical Engineering and Computer Science, Nagoya University, Nagoya 464-8603, Japan — ³Interdisciplinary Graduate School of Engineering Science, Kyushu University, Kasuga 816-8580, Japan — ⁴Department of Advanced Energy Engineering Science, Kyushu University, Kasuga 816-8580, Japan

Laser spectroscopic measurements are performed in a helicon discharge in argon. The discharge is excited by a flat coil antenna in the azimuthally isotropic m = 0 mode. The flow velocity of neutrals is measured by laser-induced fluorescence (LIF) on metastable argon atoms. Excitation is done by an external cavity diode laser (ECDL) tuned at 696.73 nm. Emitted photons (λ = 826.68 nm) are observed perpendicular to the laser beam via an intensified CCD camera. LIF is also performed on metastable argon ions via a pulsed dye laser (Δt = 5 ns) to obtain the ion velocity flow. An ion drift outwards the center with a velocity in the order of 300 m/s is observed. The velocity distribution measurements are supplemented by probe measurements of the ion density, the ion velocity flow, the electron energy distribution, and the floating and plasma potentials at different discharge conditions. The ion velocity flow is obtained by directional Langmuir probe measurements.