The effect of divertor closure on the impurity stagnation point in detached L-mode discharges on DIII-D
This paper presents experimental measurements of the location of the impurity flow stagnation point in the scrape-off-layer (SOL) of a tokamak plasma. Coherence imaging of carbon-2+ emission (465 nm) is used to track the main-chamber impurity velocity of DIII-D L-mode plasmas with B×∇B out of the di...
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/S2352179125000286 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850070051209609216 |
|---|---|
| author | M.G. Burke F. Scotti S.L. Allen W.H. Meyer A. Holm M. Zhao A.G. McLean M. Fenstermacher H.Q. Wang R. Wilcox |
| author_facet | M.G. Burke F. Scotti S.L. Allen W.H. Meyer A. Holm M. Zhao A.G. McLean M. Fenstermacher H.Q. Wang R. Wilcox |
| author_sort | M.G. Burke |
| collection | DOAJ |
| description | This paper presents experimental measurements of the location of the impurity flow stagnation point in the scrape-off-layer (SOL) of a tokamak plasma. Coherence imaging of carbon-2+ emission (465 nm) is used to track the main-chamber impurity velocity of DIII-D L-mode plasmas with B×∇B out of the divertor. The C2+ flow stagnates near the top or crown of the plasma when an open divertor (no baffling) is used. In contrast, with matched conditions and using a divertor with baffling, the C2+ flow stagnates near the outer divertor leg (X-point). The C2+ poloidal emission is hollow, peaking near the divertor legs, in the open configuration. In contrast, in the closed configuration, the C2+ emission is flat through most of the main-chamber SOL. Changing divertor dissipation from attached to detached conditions had only a minor effect on the main-chamber midplane impurity velocity. Numerical simulations using the multi-fluid edge transport code UEDGE including cross-field drifts show qualitative agreement with the open divertor experimental result. |
| format | Article |
| id | doaj-art-08765e71a3c844e3865d5df8c82e3426 |
| institution | DOAJ |
| issn | 2352-1791 |
| language | English |
| publishDate | 2025-03-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Nuclear Materials and Energy |
| spelling | doaj-art-08765e71a3c844e3865d5df8c82e34262025-08-20T02:47:37ZengElsevierNuclear Materials and Energy2352-17912025-03-014210188810.1016/j.nme.2025.101888The effect of divertor closure on the impurity stagnation point in detached L-mode discharges on DIII-DM.G. Burke0F. Scotti1S.L. Allen2W.H. Meyer3A. Holm4M. Zhao5A.G. McLean6M. Fenstermacher7H.Q. Wang8R. Wilcox9Lawrence Livermore National Laboratory, Livermore, CA, USA; Corresponding author.Lawrence Livermore National Laboratory, Livermore, CA, USALawrence Livermore National Laboratory, Livermore, CA, USALawrence Livermore National Laboratory, Livermore, CA, USALawrence Livermore National Laboratory, Livermore, CA, USALawrence Livermore National Laboratory, Livermore, CA, USALawrence Livermore National Laboratory, Livermore, CA, USALawrence Livermore National Laboratory, Livermore, CA, USAGeneral Atomics, San Diego, CA, USAOak Ridge National Laboratory, Oak Ridge, TN, USAThis paper presents experimental measurements of the location of the impurity flow stagnation point in the scrape-off-layer (SOL) of a tokamak plasma. Coherence imaging of carbon-2+ emission (465 nm) is used to track the main-chamber impurity velocity of DIII-D L-mode plasmas with B×∇B out of the divertor. The C2+ flow stagnates near the top or crown of the plasma when an open divertor (no baffling) is used. In contrast, with matched conditions and using a divertor with baffling, the C2+ flow stagnates near the outer divertor leg (X-point). The C2+ poloidal emission is hollow, peaking near the divertor legs, in the open configuration. In contrast, in the closed configuration, the C2+ emission is flat through most of the main-chamber SOL. Changing divertor dissipation from attached to detached conditions had only a minor effect on the main-chamber midplane impurity velocity. Numerical simulations using the multi-fluid edge transport code UEDGE including cross-field drifts show qualitative agreement with the open divertor experimental result.http://www.sciencedirect.com/science/article/pii/S2352179125000286TokamakDivertor |
| spellingShingle | M.G. Burke F. Scotti S.L. Allen W.H. Meyer A. Holm M. Zhao A.G. McLean M. Fenstermacher H.Q. Wang R. Wilcox The effect of divertor closure on the impurity stagnation point in detached L-mode discharges on DIII-D Nuclear Materials and Energy Tokamak Divertor |
| title | The effect of divertor closure on the impurity stagnation point in detached L-mode discharges on DIII-D |
| title_full | The effect of divertor closure on the impurity stagnation point in detached L-mode discharges on DIII-D |
| title_fullStr | The effect of divertor closure on the impurity stagnation point in detached L-mode discharges on DIII-D |
| title_full_unstemmed | The effect of divertor closure on the impurity stagnation point in detached L-mode discharges on DIII-D |
| title_short | The effect of divertor closure on the impurity stagnation point in detached L-mode discharges on DIII-D |
| title_sort | effect of divertor closure on the impurity stagnation point in detached l mode discharges on diii d |
| topic | Tokamak Divertor |
| url | http://www.sciencedirect.com/science/article/pii/S2352179125000286 |
| work_keys_str_mv | AT mgburke theeffectofdivertorclosureontheimpuritystagnationpointindetachedlmodedischargesondiiid AT fscotti theeffectofdivertorclosureontheimpuritystagnationpointindetachedlmodedischargesondiiid AT slallen theeffectofdivertorclosureontheimpuritystagnationpointindetachedlmodedischargesondiiid AT whmeyer theeffectofdivertorclosureontheimpuritystagnationpointindetachedlmodedischargesondiiid AT aholm theeffectofdivertorclosureontheimpuritystagnationpointindetachedlmodedischargesondiiid AT mzhao theeffectofdivertorclosureontheimpuritystagnationpointindetachedlmodedischargesondiiid AT agmclean theeffectofdivertorclosureontheimpuritystagnationpointindetachedlmodedischargesondiiid AT mfenstermacher theeffectofdivertorclosureontheimpuritystagnationpointindetachedlmodedischargesondiiid AT hqwang theeffectofdivertorclosureontheimpuritystagnationpointindetachedlmodedischargesondiiid AT rwilcox theeffectofdivertorclosureontheimpuritystagnationpointindetachedlmodedischargesondiiid AT mgburke effectofdivertorclosureontheimpuritystagnationpointindetachedlmodedischargesondiiid AT fscotti effectofdivertorclosureontheimpuritystagnationpointindetachedlmodedischargesondiiid AT slallen effectofdivertorclosureontheimpuritystagnationpointindetachedlmodedischargesondiiid AT whmeyer effectofdivertorclosureontheimpuritystagnationpointindetachedlmodedischargesondiiid AT aholm effectofdivertorclosureontheimpuritystagnationpointindetachedlmodedischargesondiiid AT mzhao effectofdivertorclosureontheimpuritystagnationpointindetachedlmodedischargesondiiid AT agmclean effectofdivertorclosureontheimpuritystagnationpointindetachedlmodedischargesondiiid AT mfenstermacher effectofdivertorclosureontheimpuritystagnationpointindetachedlmodedischargesondiiid AT hqwang effectofdivertorclosureontheimpuritystagnationpointindetachedlmodedischargesondiiid AT rwilcox effectofdivertorclosureontheimpuritystagnationpointindetachedlmodedischargesondiiid |