Hannover 2016 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

P: Fachverband Plasmaphysik

P 5: Poster Session- Helmholtz Graduate School for Plasma Physics

P 5.15: Poster

Monday, February 29, 2016, 16:30–19:00, Empore Lichthof

Low-Z impurity transport studies using CXRS at ASDEX Upgrade — •Cecilia Bruhn, Rachael McDermott, Ralph Dux, Clemente Angioni, Volodymyr Bobkov, Athina Kappatou, Alexander Lebschy, Thomas Pütterich, Eleonora Viezzer, and the ASDEX Upgrade Team — Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85748 Garching, Germany

Impurities in fusion plasmas arise from many sources including the erosion of material from plasma facing components and the intentional injection of impurities for control of the radiation losses. With the charge exchange recombination spectroscopy (CXRS) diagnostics at ASDEX Upgrade (AUG) the density profiles of low-Z impurity species can be measured with high spatial and temporal resolution and can, thus, be used to investigate the transport of these impurities. Previous work on this topic at AUG has focused primarily on steady state profiles, which deliver the ratio of the diffusive and convective transport coefficients. However, from the time response of the density profiles after applying an external perturbation (e.g. a fast impurity puff) the convective and diffusive components of the transport can be separately determined. The work presented here aims to achieve this by an approach that is better suited to the limited time resolution of the CXRS diagnostics; namely, a sinusoidal modulation of the boron densities invoked by modulating the power from the ion cyclotron resonance frequency (ICRF) antennas. We will present the first measurements of the boron density modulation as well as the machine and plasma parameter dependencies of the boron response to the ICRF power.