Effect of impurities on kinetic transport processes in fusion plasmas [Elektronische Ressource] / vorgelegt von Stefanie Braun

EFFECT OF IMPURITIES ON KINETICTRANSPORT PROCESSES INFUSION PLASMASI n a u g u r a l d i s s e r t a t i o nzurErlangung des akademischen Gradesdoctor rerum naturalium (Dr. rer. nat.)an der Mathematisch-Naturwissenschaftlichen FakultätderErnst-Moritz-Arndt-Universität Greifswaldvorgelegt vonStefanie Braungeboren am 07.04.1983in AachenGreifswald, 24.08.2010Dekan: Prof. Dr. Klaus Fesser1. Gutachter: Prof. Dr. Per Helander2. Gutachter: Prof. Dr. Karl-Heinz SpatschekTag der Promotion: 10.12.2010IVAbstractImpurity ions pose a potentially serious threat to fusion plasma performance by affecting theconfinement in various, usually deleterious, ways. Due to the creation of helium ash duringfusion reactions and the interaction of the plasma with the wall components, which makesit possible for heavy ions to penetrate into the core plasma, impurities can intrinsically notbe avoided. Therefore, it is essential to study their behaviour in the fusion plasma in detail.Within the framework of this thesis, different problems arising in connection with impuritieshave been investigated.Collisional damping of zonal flows in tokamaksSo-called zonal flows, i.e., poloidally and toroidally symmetric bands of plasma rotation, im-prove the confinement by reducing radial transport caused by microturbulence. They are sub-ject to a complicated interplay with the turbulence since they are created by the turbulenceitself.