Tungsten erosion during L-mode discharges in the DIII-D SAS-VW divertor
A series of L-mode plasma discharges was performed in the DIII-D tokamak to assess the impact of outer strike point (OSP) position and toroidal magnetic field direction on erosion and core contamination potential of the recently-installed, tungsten-coated Small Angle Slot (SAS-VW) divertor. In one d...
Saved in:
| Main Authors: | , , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-03-01
|
| Series: | Nuclear Materials and Energy |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2352179125000249 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1825206868685881344 |
|---|---|
| author | G. Sinclair T. Abrams M.S. Parsons S.H. Messer J. Mateja S.A. Zamperini D.M. Thomas J.D. Elder R. Maurizio T. Odstrcil R.S. Wilcox J.L. Herfindal D.D. Truong J.G. Watkins A.G. McLean D.L. Rudakov J. Ren D. Donovan |
| author_facet | G. Sinclair T. Abrams M.S. Parsons S.H. Messer J. Mateja S.A. Zamperini D.M. Thomas J.D. Elder R. Maurizio T. Odstrcil R.S. Wilcox J.L. Herfindal D.D. Truong J.G. Watkins A.G. McLean D.L. Rudakov J. Ren D. Donovan |
| author_sort | G. Sinclair |
| collection | DOAJ |
| description | A series of L-mode plasma discharges was performed in the DIII-D tokamak to assess the impact of outer strike point (OSP) position and toroidal magnetic field direction on erosion and core contamination potential of the recently-installed, tungsten-coated Small Angle Slot (SAS-VW) divertor. In one discharge, in-slot emission spectroscopy measured an < 48 % increase in the W gross erosion rate when the OSP was moved 3 cm outwards, away from the V-shaped vertex of the slot divertor. However, the effective W yield (erosion rate divided by the incident D flux) was, overall, insensitive to changes in OSP location. Consistently low estimates of the effective W yield based on measurements taken a few cm outwards from the vertex suggest potentially significant C surface contamination. No W emission signal was detected when orienting the toroidal magnetic field such that the ion B×∇B drift direction is pointed away from the X-point. However, measurements of W content in the plasma core for both toroidal magnetic field directions suggest the presence of additional, unmeasured sources of erosion. The difference in the measured core W density with OSP position is much greater than the difference in the measured erosion rates, which may suggest that the leakage of eroded impurities out of the divertor is governed primarily through the parallel ion temperature gradient and friction forces. |
| format | Article |
| id | doaj-art-57c2ec4d3b854721ba7e86f3b5d7ba32 |
| institution | Kabale University |
| issn | 2352-1791 |
| language | English |
| publishDate | 2025-03-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Nuclear Materials and Energy |
| spelling | doaj-art-57c2ec4d3b854721ba7e86f3b5d7ba322025-02-07T04:47:44ZengElsevierNuclear Materials and Energy2352-17912025-03-0142101884Tungsten erosion during L-mode discharges in the DIII-D SAS-VW divertorG. Sinclair0T. Abrams1M.S. Parsons2S.H. Messer3J. Mateja4S.A. Zamperini5D.M. Thomas6J.D. Elder7R. Maurizio8T. Odstrcil9R.S. Wilcox10J.L. Herfindal11D.D. Truong12J.G. Watkins13A.G. McLean14D.L. Rudakov15J. Ren16D. Donovan17General Atomics, San Diego, CA 92121, USA; Corresponding author.General Atomics, San Diego, CA 92121, USAThe Pennsylvania State University, University Park, PA 16802, USAUniversity of Tennessee Knoxville, Knoxville, TN 37996, USAUniversity of Tennessee Knoxville, Knoxville, TN 37996, USAGeneral Atomics, San Diego, CA 92121, USAGeneral Atomics, San Diego, CA 92121, USAUniversity of Toronto, Toronto, Ontario M3H 5T6, CanadaGeneral Atomics, San Diego, CA 92121, USAGeneral Atomics, San Diego, CA 92121, USAOak Ridge National Laboratory, Oak Ridge, TN 37830, USAOak Ridge National Laboratory, Oak Ridge, TN 37830, USASandia National Laboratories, Livermore, CA 94550, USASandia National Laboratories, Livermore, CA 94550, USALawrence Livermore National Laboratory, Livermore, CA 94550, USAUniversity of California, San Diego, San Diego, CA 92093, USAUniversity of Tennessee Knoxville, Knoxville, TN 37996, USAUniversity of Tennessee Knoxville, Knoxville, TN 37996, USAA series of L-mode plasma discharges was performed in the DIII-D tokamak to assess the impact of outer strike point (OSP) position and toroidal magnetic field direction on erosion and core contamination potential of the recently-installed, tungsten-coated Small Angle Slot (SAS-VW) divertor. In one discharge, in-slot emission spectroscopy measured an < 48 % increase in the W gross erosion rate when the OSP was moved 3 cm outwards, away from the V-shaped vertex of the slot divertor. However, the effective W yield (erosion rate divided by the incident D flux) was, overall, insensitive to changes in OSP location. Consistently low estimates of the effective W yield based on measurements taken a few cm outwards from the vertex suggest potentially significant C surface contamination. No W emission signal was detected when orienting the toroidal magnetic field such that the ion B×∇B drift direction is pointed away from the X-point. However, measurements of W content in the plasma core for both toroidal magnetic field directions suggest the presence of additional, unmeasured sources of erosion. The difference in the measured core W density with OSP position is much greater than the difference in the measured erosion rates, which may suggest that the leakage of eroded impurities out of the divertor is governed primarily through the parallel ion temperature gradient and friction forces.http://www.sciencedirect.com/science/article/pii/S2352179125000249DivertorOptical spectroscopyPlasma-material interactionsTokamaksTungsten |
| spellingShingle | G. Sinclair T. Abrams M.S. Parsons S.H. Messer J. Mateja S.A. Zamperini D.M. Thomas J.D. Elder R. Maurizio T. Odstrcil R.S. Wilcox J.L. Herfindal D.D. Truong J.G. Watkins A.G. McLean D.L. Rudakov J. Ren D. Donovan Tungsten erosion during L-mode discharges in the DIII-D SAS-VW divertor Nuclear Materials and Energy Divertor Optical spectroscopy Plasma-material interactions Tokamaks Tungsten |
| title | Tungsten erosion during L-mode discharges in the DIII-D SAS-VW divertor |
| title_full | Tungsten erosion during L-mode discharges in the DIII-D SAS-VW divertor |
| title_fullStr | Tungsten erosion during L-mode discharges in the DIII-D SAS-VW divertor |
| title_full_unstemmed | Tungsten erosion during L-mode discharges in the DIII-D SAS-VW divertor |
| title_short | Tungsten erosion during L-mode discharges in the DIII-D SAS-VW divertor |
| title_sort | tungsten erosion during l mode discharges in the diii d sas vw divertor |
| topic | Divertor Optical spectroscopy Plasma-material interactions Tokamaks Tungsten |
| url | http://www.sciencedirect.com/science/article/pii/S2352179125000249 |
| work_keys_str_mv | AT gsinclair tungstenerosionduringlmodedischargesinthediiidsasvwdivertor AT tabrams tungstenerosionduringlmodedischargesinthediiidsasvwdivertor AT msparsons tungstenerosionduringlmodedischargesinthediiidsasvwdivertor AT shmesser tungstenerosionduringlmodedischargesinthediiidsasvwdivertor AT jmateja tungstenerosionduringlmodedischargesinthediiidsasvwdivertor AT sazamperini tungstenerosionduringlmodedischargesinthediiidsasvwdivertor AT dmthomas tungstenerosionduringlmodedischargesinthediiidsasvwdivertor AT jdelder tungstenerosionduringlmodedischargesinthediiidsasvwdivertor AT rmaurizio tungstenerosionduringlmodedischargesinthediiidsasvwdivertor AT todstrcil tungstenerosionduringlmodedischargesinthediiidsasvwdivertor AT rswilcox tungstenerosionduringlmodedischargesinthediiidsasvwdivertor AT jlherfindal tungstenerosionduringlmodedischargesinthediiidsasvwdivertor AT ddtruong tungstenerosionduringlmodedischargesinthediiidsasvwdivertor AT jgwatkins tungstenerosionduringlmodedischargesinthediiidsasvwdivertor AT agmclean tungstenerosionduringlmodedischargesinthediiidsasvwdivertor AT dlrudakov tungstenerosionduringlmodedischargesinthediiidsasvwdivertor AT jren tungstenerosionduringlmodedischargesinthediiidsasvwdivertor AT ddonovan tungstenerosionduringlmodedischargesinthediiidsasvwdivertor |