Development of an integrated core–edge scenario using the super H-mode
Abstract
An optimized pedestal regime called the super-H (SH) mode is leveraged to couple a fusion relevant core plasma with a high density scrape-off layer appropriate for realistic reactor power exhaust solutions. Recent DIII-D experiments have expanded the operating space of the SH regime using advanced control algorithms and investigated optimization of impurity seeding, deuterium gas puffing, and 3D magnetic perturbations. Simultaneous real-time control of the pedestal density and radiated power with in-vessel coils and nitrogen seeding enable optimal coupled divertor and pedestal conditions. Four case studies are analysed with varied levels of radiated power in the divertor volume ranging from 0 (no seeding) to 8.5 MW radiated from carbon and nitrogen emission. Plasmas with a 4.5 MW radiated power target establish a radiative mantle, leading to divertor temperatures of ∼16 eV while maintaining SH-mode, and with only marginal impact on the pedestal and core performance. Increased levels of N2 seeding with a 7.5 MW radiated power target facilitate detachment onset and divertor temperatures 2.5{\tau }_{\text{E}}$?> > 2.5 τ E . Finally, a 8.5 MW radiated power target leads to partial detachment, which is so far associated with the loss of access to SH-mode pedestal conditions.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 22, 2021
- Source ID
- 10.1088/1741-4326/ac34d6
Entities
People
- Adam McClean
- Brian Grierson
- C.J. Lasnier
- Carlos Paz-Soldan
- Colin Chrystal
- David Eldon
- F. Scotti
- Florian M. Laggner
- Huiqian Wang
- J.G. Watkins
- Jerry Hughes
- L. Casali
- Matthias Knolker
- Philip Benjamin Snyder
- T. M. Wilks
- T. Osborne
Organizations
- Office of Fusion Energy Sciences