Abstract
At low ι (∼ 0.34), W7-AS is operated with limiter; smooth flux surfaces extend into the limiter shadow. At higher ι, the plasma surface is separatrix dominated. The resonant 5/ m island chain gives rise to corrugated surfaces. This paper deals with two difficulties on the way to a complete edge transport modelling in this complex 3D geometry. (1) At low ι, strong deviations from exponential edge density decay (shoulders) are observed. Measurements with reversed B-field indicate that they are caused by superimposed, stationary E θ × B particle drifts. (2) The open edge topology of the corrugated high ι case cannot be represented by standard magnetic coordinates. As a first step towards 3D modelling, the open structures were parametrized on the basis of the flux conserving, open magnetic surface concept. As a first application, wall recycling fluxes for a low density ECRH discharge have been derived by mapping Langmuir probe data onto the wall along the open surfaces and used to simulate the 3D neutral gas distribution with the EIRENE code.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
