Mainz 2022 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
P: Fachverband Plasmaphysik
P 19: Poster II
P 19.25: Poster
Thursday, March 31, 2022, 16:00–17:30, P
Determination of 2D Filament Temperatures and Densities at ASDEX Upgrade with the Thermal Helium Beam Diagnostic — •Daniel Wendler1,2, Michael Griener1, Gregor Birkenmeier1,2, Rainer Fischer1, Ralph Dux1, Elisabeth Wolfrum1, Ulrich Stroth1,2, and the ASDEX Upgrade team1 — 1Max-Planck- Institut für Plasmaphysik, Garching, Germany — 2Physik Department E28, TUM, Garching, Germany
In all plasma scenarios in magnetic confinement fusion, small filamentary structures appear in the scrape-off layer (SOL), called blobs, with a locally strongly enhanced density which propagate convectively outwards. Blobs contribute to reactor relevant phenomena like the density shoulder formation, large first wall particle and power fluxes close to the density limit and the broadening of the divertor heat flux fall-off length. To calculate the effective power flux which is carried by the filaments, temperature and density as well as the frequency and velocity of filaments have to be determined. While the measurements of mean filament velocities are routinely made with various diagnostics, the simultaneous non-invasive measurement of temperatures and densities of single filaments is now possible with the thermal helium beam diagnostic at ASDEX Upgrade. By means of a grid of 2D distributed lines of sight, the temperature, density and velocities as well as the filament shape can be determined in two dimensions. A dedicated numerical approach based on a collisional-radiative model for the determination of blob temperatures and densities is presented and first measurements of temperatures and densities of blobs in two dimensions are presented.