Impact of localized gas injection on ICRF coupling and SOL parameters in JET-ILW H-mode plasmas
Impact of localized gas injection on ICRF coupling and SOL parameters in JET-ILW H-mode plasmas
Recent JET-ILW [1,2] experiments reiterated the importance of tuning the plasma fuelling in order to optimize ion cyclotron resonance frequency (ICRF) heating in high power H-mode discharges. By fuelling the plasma from gas injection modules (GIMs) located in the mid-plane and on the top of the mach...
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Personal Name(s): | Lerche, E. (Corresponding author) |
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Goniche, M. / Jacquet, P. / Bobkov, V. / Colas, L. / Czarnecka, A. / Brezinsek, Sebastijan / Brix, M. / Graham, M. / Groth, M. / Monakhov, I. / Mathurin, T. / Matthews, G. / Meneses, L. / Noble, C. / Petrzilka, V. / Rimini, F. / Shaw, A. / Eester, van / Crombe | |
Contributing Institute: |
Plasmaphysik; IEK-4 |
Published in: | Journal of nuclear materials, 463 (2015) S. 634 - 639 |
Imprint: |
Amsterdam [u.a.]
Elsevier Science
2015
|
DOI: |
10.1016/j.jnucmat.2014.10.074 |
Document Type: |
Journal Article |
Research Program: |
Plasma-Wall-Interaction |
Publikationsportal JuSER |
Recent JET-ILW [1,2] experiments reiterated the importance of tuning the plasma fuelling in order to optimize ion cyclotron resonance frequency (ICRF) heating in high power H-mode discharges. By fuelling the plasma from gas injection modules (GIMs) located in the mid-plane and on the top of the machine instead of adopting the more standardly used divertor GIMs, a considerable increase of the ICRF antenna coupling resistances was achieved with moderate gas injection rates (<1.5 × 1022 e/s). This effect is explained by an increase of the scrape-off-layer density in front of the antennas when mid-plane and top fuelling is used. By distributing the gas injection to optimize the coupling of all ICRF antenna arrays simultaneously, a substantial increase in the ICRF power capability and reliability was attained. Although similar core/pedestal plasma properties were observed for the different injection cases, the experiments indicate that the RF-induced impurity sources are reduced when switching from divertor to main chamber gas injection. |