The Influence of Three-dimensional Stochastic Magnetic Boundaries on Plasma Edge Transport and the Resulting Plasma Wall Interaction
- Forschungszentrum Julich, Julich, Germany
- General Atomics, San Diego
- Lawrence Livermore National Laboratory (LLNL)
- Oak Ridge National Laboratory (ORNL)
- University of California, San Diego
- Max-Planck-Institute for Plasmaphysik, EURATOM-Association, Greifswald, Germany
- ITER Organization, Cadarache, France
- University of California, San Diego & La Jolla
- Columbia University
- EURATOM / FZ-Juelich, Germany
- ORNL
- Sandia National Laboratories (SNL)
The three-dimensional (3D) features of plasma edge profiles and wall interaction patterns induced by edge resonant magnetic perturbation fields (RMP) are discussed comparing TEXTOR and DIII-D. We show that the scrape-off layer (SOL) profiles and decay lengths depend the edge safety factor, the RMP base mode as well as on the plasma rotation during RMP application indicating modification of SOL transport by the 3D perturbation fields. This is compatible with channeling of particle and heat efflux along open perturbed field lines in the very edge of the plasma boundary into a completely re-arranged, helically striated 3D divertor footprint. The distribution of the measured divertor heat and particle fluxes at DIII-D match the vacuum modeled magnetic footprint topology in L-mode while in H-mode the striation width exceeds the modeled footprint width by 15-30%. This 3D structure of the measured heat and particle fluxes results in a new situation for the material erosion properties and initial quantification of the net-erosion within the 3D footprint shows in L-mode a 50% decrease of the chemical erosion yield and evidence for a comparably small 15-20% increase in physical sputtering. Extrapolation of these findings to ITER by vacuum modeling of the magnetic footprint for the actual ELM control coils shows a similar vacuum magnetic footprint topology as found at DIII-D during RMP ELM suppression. However, the open field lines escape the CFC covered ITER divertor area potentially transferring net-erosion characteristics from the CFC domain onto the Tungsten including so far unconsidered heat and particle loads on this sensitive material.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 1038503
- Resource Relation:
- Conference: 19th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices (PSI), San Diego, CA, USA, 20100524, 20100528
- Country of Publication:
- United States
- Language:
- English
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