Berlin 2001 – scientific programme

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P: Plasmaphysik

P 8: Magnetic Confinement and Plasma Technology (Poster Session)

P 8.7: Poster

Monday, April 2, 2001, 12:30–15:00, AT2

Detection of Neutral Beam Generated Suprathermal Electrons by Thomson Scattering on ASDEX Upgrade — •Bernd Kurzan, Heindieter Murmann, Martin Jakobi, Denis Bolshukhin, Wolfgang Suttrop, and ASDEX Upgrade Team — Max-Planck-Institut für Plasmaphysik, EURATOM Association, Boltzmannstr. 2, 85748 Garching

On the ASDEX Upgrade tokamak a Thomson scattering apparatus with 50^o scattering, and laser beams running tangetially to the toroidal direction, is now in operation. This diagnostic measures spatially resolved the electron energy distribution nearly parallel to the toroidal magnetic field. This is a supplement to the already existing Thomson scattering apparatus with 90^o scattering where the laser beams run vertically in the poloidal plain, and which measures spatially resolved the electron energy distribution perpendicular to the magnetic field. During neutral beam injection with a power P ≥ 5 MW in low density plasmas, n_e ≤ 4*10¹⁹ m⁻³, the Thomson scattering diagnostics measure in the plasma center an increase of the mean parallel electron energy to about 20 keV, while their mean perpendicular energy is in the range of 4-5 keV. The values of the perpendicular and parallel energies are confirmed by electron cyclotron resonance emission measurements and spectra of the soft x-ray radiation respectively. The experimental results are discussed and compared to model calculations.