München 2019 – wissenschaftliches Programm
P 5.3: Vortrag
Montag, 18. März 2019, 14:55–15:20, HS 21
PIC simulations of the extraction region of one beamlet of an ITER NBI relevant ion source — •Ivar Mauricio Montellano Duran, Serhiy Mochalskyy, Dirk Wünderlich, and Ursel Fantz — MaxPlanck-Institut für Plasmaphysik, 85748 Garching, Germany
For ITER NBI ion sources will be used to produce large and intense negative hydrogen or deuterium ion beams. Negative ions are produced predominantly by the surface process in a low temperature plasma. In order to gain a better understanding of the complex ion source physics, close to the surface, self-consistent models are needed. The magnetic field topology close to the extraction system demands 3D models to study the particle transport in the plasma. The 3D Particle in cell (PIC) ONIX code has been already validated and applied for the extraction of negative hydrogen ions and co-extracted electrons for one extraction aperture of the ITER NBI prototype source. The source performance is typically limited by the amount of co-extracted electrons which is significantly higher in deuterium than in hydrogen. In the experiments several parameters can be modified to reduce the co-extracted electron current such as strength and topology of the magnetic fields. Simulations with different magnetic field configurations were done to study their effect on the electron transport. A comparison between deuterium and hydrogen plasma simulations was realized to obtain an insight of the isotope effect. The results of these simulations and a discussion on the transport of the electrons are presented.