This title appears in the Scientific Report :
2017
Please use the identifier:
http://dx.doi.org/10.1088/0029-5515/56/4/046012 in citations.
Comparison of H-mode plasmas in JET-ILW and JET-C with and without nitrogen seeding
Comparison of H-mode plasmas in JET-ILW and JET-C with and without nitrogen seeding
In high confinement mode, highly shaped plasmas with edge localized modes in JET, and for heating power of 15–17 MW, the edge fluid code EDGE2D-EIRENE predicts transition to detachment assisted by nitrogen at the low field side (LFS) target when more than 50% of the power crossing the separatrix bet...
Saved in:
Personal Name(s): | Jaervinen, A. E. (Corresponding author) |
---|---|
Giroud, C. / Groth, M. / Belo, P. / Brezinsek, S. / Beurskens, M. / Corrigan, G. / Devaux, S. / Drewelow, P. / Harting, D. / Huber, A. / jachmich / Lawson, K. / Lipschultz, B. / Maddison, G. / Maggi, C. / Marchetto, C. / Marsen, S. / Matthews, G. F. / Meigs, A. G. / Moulton, D. / Sieglin, B. / Stamp, M. F. / Wiesen, S. | |
Contributing Institute: |
Plasmaphysik; IEK-4 |
Published in: | Nuclear fusion, 56 (2016) 4, S. 046012 - |
Imprint: |
Vienna
IAEA
2016
|
DOI: |
10.1088/0029-5515/56/4/046012 |
Document Type: |
Journal Article |
Research Program: |
Plasma-Wall-Interaction |
Publikationsportal JuSER |
In high confinement mode, highly shaped plasmas with edge localized modes in JET, and for heating power of 15–17 MW, the edge fluid code EDGE2D-EIRENE predicts transition to detachment assisted by nitrogen at the low field side (LFS) target when more than 50% of the power crossing the separatrix between ELMs is radiated in the divertor chamber, i.e. ~4 MW. This is observed both in the ITER-like wall (JET-ILW) and in the carbon wall (JET-C) configurations and is consistent with experimental observations within their uncertainty. In these conditions, peak heat fluxes below 1 MW m−2 are measured at the LFS target and predicted for both wall configurations. When the JET-C configuration is replaced with the JET-ILW, a factor of two reduction in the divertor radiated power and 25–50% increase in the peak and total power deposited to the LFS divertor plate is predicted by EDGE2D-EIRENE for unseeded plasmas similar to experimental observations. At the detachment threshold, EDGE2D-EIRENE shows that nitrogen radiates more than 80% of the total divertor radiation in JET-ILW with beryllium contributing less than a few %. With JET-C, nitrogen radiates more than 70% with carbon providing less than 20% of the total radiation. Therefore, the lower intrinsic divertor radiation with JET-ILW is compensated by stronger nitrogen radiation contribution in simulations leading to detachment at similar total divertor radiation fractions. 20–100% higher deuterium molecular fraction in the divertor recycling fluxes is predicted with light JET-C materials when compared to heavy tungsten. EDGE2D-EIRENE simulations indicate that the stronger molecular contribution can reduce the divertor peak power deposition in high recycling conditions by 10–20% due to enhanced power dissipation by molecular interaction. |