Speaker
Dr
Adrianus Sips
(JET Exploitation Unit)
Description
In the last two years the Integrated Operation Scenarios Topical Group (IOS-TG) of the ITPA IOS-TG has combined results of joint experiments with other data available at q95~3 in a database of global parameters with ~3300 entries of stationary discharges from AUG, C-Mod, DIII-D, JET and JT-60U for both carbon wall and metal wall experiments. The analyses focus on discharges that are stationary for ≥5 energy confinement times.
Compared to carbon wall data, experiments with metal walls (AUG, JET-ILW, and C-Mod) have (so-far) not found a way to access the low collision frequencies (as defined in [1]). No difference in performance is observed between carbon wall and metal wall discharges at high collisionality. Stationary discharges at q95~3 and H98(y,2)~1.0 are typically obtained at βN~2.0, using pre-dominantly co-current NBI heating (AUG, DIII-D and JET). In experiments using a metal walls in AUG, C-Mod H-mode and JET, the confinement is significantly reduced (H98(y,2)~0.8-0.9) at βN≤1.8. The figure of merit G ≡ H89xN/q952 should be 0.42 for Q=10 in ITER (note H89 is used here). For carbon wall data, G spans a range of 0.25 to 0.51 at the ITER reference beta of N=1.8, while for data obtained with metal walls G varies from 0.23 to 0.36. More specifically, G>0.4 has only been obtained at N>2.5 for metal devices operating at q95~3, using dominant co-current NBI heating (AUG and JET). The ITER requirement for operation at fGW=0.85 can be obtained for triangularities (separatrix) in the range 0.2 to 0.45; an issue for ITER is that at the design value x=0.49 or higher, DIII-D and C-mod (metal wall) have no data for fGW > 0.8 and H98(y,2) > 0.95.
This material is based upon work supported by DOE under Awards DE-FC02-04ER546984 and DE-AC02-09CH114668. This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission.
[1] T.C. Luce, et al, Nucl. Fusion 54 (2014) 013015.
| Country or International Organization | European Commission |
|---|---|
| Paper Number | EX/P6-42 |
Primary author
Dr
Adrianus Sips
(JET Exploitation Unit)
Co-authors
Dr
Charles Kessel
(Princeton Plasma Physics Laboratory)
Dr
Emmanuel Joffrin
(CEA)
Dr
Fernanda Rimini
(CCFE, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB, UK.)
Dr
Gary L. Jackson
(General Atomics)
Dr
Hajime Urano
(JAEA)
Dr
Isabel Maria Ferreira Nunes
(IPFN/IST)
Dr
Joerg Hobirk
(Max-Planck-Institut für Plasmaphysik, Garching D-85748, Germany)
Dr
Joerg Stober
(IPP Garching)
Dr
Josef Schweinzer
(IPP Garching)
Dr
Peter Lomas
(CCFE, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB, UK)
Dr
Shunsuke Ide
(Japan Atomic Energy Agency)
Dr
Steve Wolfe
(Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachussetts, USA)
Dr
Thomas Puetterich
(Max-Planck-Institut für Plasmaphysik, Garching D-85748, Germany)
Dr
Timothy C. Luce
(General Atomics)
