Approaching detachment in I-mode—response of core confinement and the edge pedestal in the ASDEX Upgrade tokamak
- 31 December 2020
- journal article
- research article
- Published by IOP Publishing in Nuclear Fusion
- Vol. 61 (3), 036026
- https://doi.org/10.1088/1741-4326/abd7b7
Abstract
Experiments on nitrogen assisted divertor detachment in the improved energy confinement mode (I-mode) are reported from the ASDEX Upgrade tokamak. When nitrogen is introduced into the divertor and radiation losses cool the divertor plasma down, a loss of core confinement is observed, concomitant with an increase in low frequency edge fluctuation levels. The loss in confinement can be compensated and the I-mode can be maintained by additional heating power input. Detachment of the inner divertor leg has been observed for the first time in an I-mode discharge. The outer divertor leg remains attached in these experiments. Good energy confinement properties (H98(y,2) = 0.9) during the detachment of the inner divertor leg are reported.Keywords
Funding Information
- EUROfusion Consortium (633053)
- US Department of Energy (DE-AC05-00OR22725)
This publication has 79 references indexed in Scilit:
- L- to H-mode transitions at low density in ASDEX UpgradeNuclear Fusion, 2011
- Edge energy transport barrier and turbulence in the I-mode regime on Alcator C-ModPhysics of Plasmas, 2011
- I-mode: an H-mode energy confinement regime with L-mode particle transport in Alcator C-ModNuclear Fusion, 2010
- Edge radial electric field structure and its connections to H-mode confinement in Alcator C-Mod plasmasPhysics of Plasmas, 2009
- Effect of B×∇B direction on SOL energy transport in JETJournal of Nuclear Materials, 2005
- Magnetic triggering of ELMs in TCVPlasma Physics and Controlled Fusion, 2003
- New results from the tungsten programme at ASDEX UpgradeJournal of Nuclear Materials, 2003
- Ultrafast broadband frequency modulation of a continuous wave reflectometry system to measure density profiles on ASDEX UpgradeReview of Scientific Instruments, 1996
- Observation of Continuous Divertor Detachment in-Mode Discharges in ASDEX UpgradePhysical Review Letters, 1995
- Scalings for tokamak energy confinementNuclear Fusion, 1990