| Autor: |
S.H. Messer, J.D. Mateja, J.H. Nichols, A. Cacheris, J.D. Duran, S.A. Zamperini, G. Sinclair, D. Donovan, T. Abrams, T. Odstrcil, J. Ren, W. Garcia, E.A. Unterberg, P.C. Stangeby, D.L. Rudakov, J.D. Elder, J. Watkins |
| Jazyk: |
angličtina |
| Rok vydání: |
2024 |
| Předmět: |
|
| Zdroj: |
Nuclear Materials and Energy, Vol 38, Iss , Pp 101566- (2024) |
| Druh dokumentu: |
article |
| ISSN: |
2352-1791 |
| DOI: |
10.1016/j.nme.2023.101566 |
| Popis: |
Experimental results from the 2022 tungsten (W)-coated Small Angle Slot (SAS-VW) divertor campaign at DIII-D coupled with interpretive 3DLIM modelling show opposing trends for core impurity content when compared to impurity deposition on far-Scrape Off Layer (SOL) Collector Probes (CPs) with increasing main ion density. SAS-VW is a closed, W-coated divertor designed to more easily facilitate divertor detachment while reducing impurity leakage. An experiment performed a series of upper-single-null L-mode discharges in each toroidal magnetic field (BT) direction, with increasing main ion density (line-averaged density = 3.15–4.35e19 m−3) that approaches and slightly exceeds the divertor detachment threshold. The results indicate: a) increased radial W transport with decreasing peak Te,tLP; and b) negligible change in W content in the far-SOL at the outer mid-plane with the onset of divertor detachment.Preliminary W deposition measurements using double-sided, graphite CPs inserted at the Midplane Materials Evaluation System (MiMES) reveal a 75% decrease over the density scan when operating in the unfavorable (ion B×∇B out of the divertor) BT direction. In contrast, soft X-ray (SXR) radiation from the same discharges is used as a proxy for W core contamination, showing core W content that increases by 77% with increasing line-averaged density. Similar L-mode discharges conducted in the favorable BT direction result in significantly less deposition on CPs.Using an interpretive modeling workflow following Zamperini 2022 [1] for assessing the transport of W sputtered from the SAS-VW divertor, the analysis suggests that W migration to the main chamber surfaces during the campaign may also contribute to far-SOL deposition. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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