Progress toward divertor detachment on TCV within H-mode operating parameters

Harrison, JR; Theiler, C; Février, O; Oliviera, H de; Maurizio, R; Verhaegh, K; Perek, A; Karpushov, A; Lipschultz, B; Duval, BP; Feng, X; Henderson, S; Labit, B; Linehan, B; Merle, A; Reimerdes, H; Sheikh, U; Tsui, CK; Vijvers, WAJ; Wüthrich, C

Abstract

Recent experiments on Tokamak à Configuration Variable have made significant progress toward partial detachment of the outer divertor in neutral beam heated H-mode plasmas in conventional and alternative divertor configurations. The heating power required to enter H-mode was measured in a range of divertor configurations. It is found that at the core densities most favourable for H-mode access, the L–H threshold power is largely independent of the poloidal flux expansion and major radius of the outer divertor, and in the snowflake minus configuration. A factor 2 reduction in the outer divertor power load was achieved in ELM-free (using a fuelling and nitrogen seeding) and ELMy (using nitrogen seeding) H-mode plasmas. No significant reduction in the outer divertor particle flux was achieved in the ELM-free scenarios, compared with ~30% reduction in the most strongly detached ELMy cases. The poloidal flux expansion at the outer divertor was not found to significantly alter the cooling of the divertor in the ELM-free scenarios.

Citation

Harrison, J., Theiler, C., Février, O., Oliviera, H. D., Maurizio, R., Verhaegh, K., …Wüthrich, C. (2019). Progress toward divertor detachment on TCV within H-mode operating parameters. Plasma Physics and Controlled Fusion, 61(6), Article 065024. https://doi.org/10.1088/1361-6587/ab140e

• Journal Article Type: Article
• Acceptance Date: Mar 27, 2019
• Online Publication Date: May 16, 2019
• Publication Date: Jun 30, 2019
• Deposit Date: Jun 5, 2019
• Publicly Available Date: Jun 5, 2019
• Journal: Plasma Physics and Controlled Fusion
• Print ISSN: 0741-3335
• Electronic ISSN: 1361-6587
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 61
• Issue: 6
• Article Number: 065024
• DOI: https://doi.org/10.1088/1361-6587/ab140e