Separatrix-to-Wall Simulations of Impurity Transport with a Fully Three-Dimensional Wall in DIII-D

Abstract

A novel multicode workflow to interpret collector probe deposition patterns in DIII-D has been developed. The components of the workflow consist of a detailed computer-aided-design file of the vessel wall and the scrape-off-layer (SOL) codes MAFOT, OSM, DIVIMP, and 3DLIM. A special-purpose toolkit enables passing the output of these codes among each other to provide a full-SOL picture of impurity transport. A demonstration of the workflow is described to support evidence of near-SOL tungsten parallel accumulation during trace W impurity experiments on DIII-D. Iteration between simulated deposition patterns in 3DLIM and DIVIMP predicts a region of elevated W density near the separatrix about halfway between the outboard midplane and the top of the plasma. This workflow will be used to better interpret collector probe experiments on DIII-D.

Keywords:

• DIII-D
• impurity transport
• collector probes
• scrape-off layer

Acknowledgments

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This material is based upon work supported by the U.S. Department of Energy (DOE), Office of Science, Office of Fusion Energy Sciences using the DIII-D National Fusion Facility, a DOE Office of Science user facility, under award numbers DE-FC02-04ER54698, DE-SC0019256, DE-AC05-00OR22725, and DE-FG02-07ER54917.