München 2019 – wissenschaftliches Programm
P 18.55: Poster
Donnerstag, 21. März 2019, 16:30–18:30, Foyer Audimax
First operation of the NBI system at Wendelstein 7-X — •Annabelle Spanier1,2, Dirk Hartmann2, Paul McNeely2, Norbert Rust2, and Robert Wolf1,2 for the The Wendelstein 7-X Team collaboration — 1Technische Universität Berlin, Berlin, Germany — 2Max Planck Institute for Plasma Physics, Greifswald, Germany
Neutral beam injection (NBI) heating was used at the superconducting optimized stellarator Wendelstein 7-X for the first time during the experimental campaign OP1.2b in 2018. The injector is equipped with two inductively coupled ion sources that can accelerate positively charged hydrogen ions up to 55 keV. The maximum combined heating power is 3.4 MW. A second injector is planned to be operational in summer 2019.
In comparison to other heating methods, NBI is not only a source of energy but also of fast particles. Therefore, one can modify the density and temperature profiles of a plasma. For example, at high density further density peaking was observed.
The energy flow in the NBI system is being investigated in detail. The focus is on the energy distribution of the accelerated ions, the dependence of the extracted current on the ambient magnetic field of W7-X and the dependence of the perveance on the beam parameters.