This title appears in the Scientific Report :
2021
The resiliance of highly dissipative exhaust scenarios at JET to seed impurity mixes and divertor geometry
The resiliance of highly dissipative exhaust scenarios at JET to seed impurity mixes and divertor geometry
The resiliance of highly dissipative exhaust scenarios at JET to seedimpurity mixes and divertor geometryM. Wischmeiera, A. Huberd, C.G. Lowryb, S. Wiesend, M. Bernerta, S. Gl ̈ogglera, M.L.Reinkee, G. Calabroc, C. Guillemautf, S. Brezinsekd, S. Hendersonf, B. Lomanowskie, C.F.Maggif, A. Meigsf, G....
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Personal Name(s): | Wischmeier, M. |
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Huber, Alexander (Corresponding author) / Lowry, C. G. / Wiesen, S. / Bernert, M. / Glöggler, S. / Reinke, M. L. / Calabro, G. / Guillemaut, C. / Brezinsek, S. / Henderson, S. / Lomanowski, B. / Maggi, C. F. / Meigs, A. / Sergienko, G. / Sips, G. | |
Contributing Institute: |
Plasmaphysik; IEK-4 |
Imprint: |
2021
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Conference: | 24th International Conference on Plasma Surface Interactions in Controlled Fusion Devices (PSI 2020), virtuell (virtuell), 2021-01-25 - 2021-01-29 |
Document Type: |
Abstract |
Research Program: |
Plasma-Wand-Wechselwirkung |
Publikationsportal JuSER |
The resiliance of highly dissipative exhaust scenarios at JET to seedimpurity mixes and divertor geometryM. Wischmeiera, A. Huberd, C.G. Lowryb, S. Wiesend, M. Bernerta, S. Gl ̈ogglera, M.L.Reinkee, G. Calabroc, C. Guillemautf, S. Brezinsekd, S. Hendersonf, B. Lomanowskie, C.F.Maggif, A. Meigsf, G. Sergienkod, G.Sipsa, and JET contributors1EUROfusion Consortium, JET, Culham Science Centre, Abingdon, OX14 3DB, UKaMax-Planck-Institut f ̈ur Plasmaphysik, 85748 Garching bei M ̈unchen, GermanybEuropean Commision, B-1049 Brussels, BelgiumcENEA for EUROfusion, via E. Fermi 45, 00044 Frascati, ItalydForschungszentrum J ̈ulich GmbH, Institut f ̈ur Energie- und Klimaforschung - Plasmaphysik, 52425 J ̈ulich,GermanyeOak Ridge National Laboratory, Oak Ridge, TN 37831, USAfCCFE, Culham Science Centre, Abingdon, Oxon, OX14 3DB, UKgVTT Technical Research Centre of Finland, FI-02044 VTT, Finlandmarco.wischmeier@ipp.mpg.deThe engineering limits in a fusion power plant, FPP, with radiation damages expected to bebetween 20-50 dpa require the power load to the divertor target plates to be limited to∼10M W/m2. With impurity radiation and neutrals contributing strongly to the peak powerload onto the target plates, the power flux carried by charged particles is restricted to be below5M W/m2. With an ITER like lower single null divertor the power dissipation,fdiss, betweenthe core plasma and the divertor target plates is then required to be>90%of the total losspower. The total dissipation accounts for losses from radiation, perpendicular transport andCX processes. While ITER is expected to radiate 30% of the loss power in the core, a FPPmay be required to radiate up to 70% on closed field lines [1]. In order to not undermine coreperformance this radiation will need to be concentrated in area between the pedestal top andthe last closed flux surface. The required power load restriction combined with the desire toenhance the life time in view of erosion (Te<5eV) would imply completely detached divertortargets and only small/tiny or no ELMs.On JET with metal PFCs highly dissipative regimes with completely detached divertor targetsand small and no ELM regimes have been achieved using a variety of seeding species [2,3].E.g. with Ne seeding at heating powers of up to∼35M WELM free L-M-mode transitionswere obtained with targetTe<3eVand an H98y of up to 0.95. For the loss of Ne as seedingimpurity the dynamics of the re-attachment process will be reported. Varying the admixture ofAr andN2alters the ratio of core to divertor radiation but not the achievablefdisswith com-pletely detached divertor targets. For the same fueling gas throughput confinement in unseededJET ILW discharges with an open horizontal divertor (CC) is improved compared to verticaltarget geometry (VV). However, withN2as well as with Kr seeding the maximum achievablefdissare equal for both configurations, with confinement being equal and degraded comparedto CC but similar to unseeded VV conditions.[1] M. Wischmeier et al., J. Nucl. Mater.463(2015) 22, [2] S. Gl ̈oggler et al., Nuclear Fusion59(2019) 126031, [3] M. Bernert at al., Nucl. Mat. and Energy12(2017) 11 |