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., Perek, A., Karpushov, A., Lipschultz, B., Duval, B., Feng, X., Henderson, S., Labit, B., Linehan, B., Merle, A., Reimerdes, H., Sheikh, U., Tsui, C., Vijvers, W., & 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
• Public URL: https://durham-repository.worktribe.com/output/1329448