München 2019 – wissenschaftliches Programm
P 18.63: Poster
Donnerstag, 21. März 2019, 16:30–18:30, Foyer Audimax
Impact of Tracer-Encapsulated Solid Pellets (TESPEL) on Wendelstein 7-X plasmas — •René Bussiahn1, Naoki Tamura2, Kieran Joseph McCarthy3, LHD experiment group2, and W7-X team1 — 1Max-Planck-Institute for Plasma Physics, Greifswald, Germany — 2National Institute for Fusion Science(NIFS), Toki, Japan — 3Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, Madrid, Spain
A Tracer-Encapsulated Solid Pellet (TESPEL) injection system, developed by the National Institute for Fusion Science(NIFS), Japan was installed before, and commissioned during, the OP1.2b operation phase of the stellarator Wendelstein 7-X. The method allows depositing impurity tracers within a well localized region of the W7-X core plasma for impurity transport studies. A short-term perturbation of the plasma due to the ablation of the polystyrene shell and the actual tracer particles of the TESPEL is seen in time-resolved ne and Te -profiles (Thomson scattering) while a simultaneous reduction of plasma turbulence is also observed in phase contrast imaging (PCI) data. The formation of an ablation cloud and its spread along the magnetic field lines has been observed by means of a fast frame camera. A soft X-ray tomography system (XMCTS) was used to observe temporal changes in the 2D X-ray emissivity profiles. Vacuum ultraviolet spectroscopy (HEXOS) as well as the X-ray Imaging Crystal Spectrometer (XICS) have been employed to observe the temporal radiation evolution for impurity transport studies.