A series of L-mode discharges in upper single null configuration with more than 30 s duration were performed in the WEST tokamak with the strike line on actively cooled tungsten-coated divertor components. This series of discharges accumulated 20 min of plasma and a strike point fluence of » ´ – 2 10 m25 2 in two days of operation in attached conditions. The discharges showed good density control, no tungsten accumulation and overall very benign thermal behaviour of the upper divertor. A subset of the discharges were seeded with nitrogen either in the divertor or midplane region to study plasma-wall interaction and associated ammonia formation in this weakly pumped scenario with all-tungsten plasma-facing components. While ammonia signals remained too weak for useful analysis, a strong dependence of nitrogen plasma penetration efficiency and residence time on the injection location was found. This hints towards a currently underestimated plasma-near nitrogen reservoir in these tokamak discharges in divertor configuration.
Long pulse D2 and N2 seeded discharges on the upper actively cooled tungsten divertor of WEST
Dittmar T.; Loarer T.; Drenik A.; Bourdelle C.; Brezinsek S.; Desgranges C.; Douai D.; Fedorczak N.; Guirlet R.; Gunn J.; Meyer O.; Laguardia L.; Tsitrone E.; the WEST team
ID | 463233 |
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DOI | 10.1088/1402-4896/ab753f |
PRODUCT TYPE | Journal Article |
LAST UPDATE | 2023-07-04T17:55:50Z |
EU PROJECT | EUROfusion |
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TITLE | Implementation of activities described in the Roadmap to Fusion during Horizon 2020 through a Joint programme of the members of the EUROfusion consortium |
FOUNDING PROGRAM | H2020 |