TY  - CONF
AU  - Boeyaert, D.
AU  - Wiesen, S.
AU  - Wischmeier, M.
AU  - Dekeyser, W.
AU  - Carli, S.
AU  - Wang, L.
AU  - Ding, F.
AU  - Li, K.
AU  - Liang, Y.
AU  - Baelmans, M.
TI  - Assessment of plasma edge transport in Neon seeded plasmas in disconnected double null configuration in EAST with SOLPS-ITER
M1  - FZJ-2021-01566
PY  - 2021
AB  - Assessment of plasma edge transport in Neon seeded plasmas in disconnected double null configuration in EAST with SOLPS-ITERD. Boeyaert1,3, S. Wiesen1, M. Wischmeier2, W. Dekeyser3, S. Carli3, L. Wang4, F. Ding4, K. Li4, Y. Liang1,4, M. Baelmans3, and the EAST-teama1Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung – Plasmaphysik, D-52425 Jülich, Germany2Max-Planck-Institut für Plasmaphysik, Boltzmannstraße 2, 85748 Garching, Germany3KU Leuven, Department of Mechanical Engineering, Celestijnenlaan 300, 3001 Leuven, Belgium4Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, People’s Republic of China aSee appendix of Wan B.N. et al 2019 Nucl. Fusion 59 112003 d.boeyaert@fz-juelich.dePower  and  particle  exhaust  is  essential  for  future  nuclear  fusion  reactors  [1].   This exhaust is determined by the perpendicular/radial transport inside the Scrape-Off Layer (SOL) which include drifts and currents, neutral kinetics, radiation and (radial) anomalous transport. Under high power conditions in future all-metal fusion devices like ITER or DEMO, extrinsic impurity seeding is required to induce divertor detachment through impurity radiation. Due to the lack of surface chemistry, noble gases like neon (Ne) are key candidates as main radiator. Besides  JET  [2],  EAST  is  the  only  tokamak  that  currently  handles  stable  H-modes  with  Neseeding in a metallic environment as the main (upper) divertor is made out of tungsten. This device has  the  flexibility  to  do  both upper single  null  (USN)  and  double  null  (DN)  configurations  with  the  latter  showing  good  prospects  to  handle  exhaust  with  good  core  confinement [3]. USN discharges in EAST are setup as disconnected DN (DDN) with a large separation between separatrices upstream (drsep) of about ~ 2cm. This causes a remaining influx of eroded C impurities from the lower (non-active) divertor.  This  contribution  analyzes Ne  seeded  and  unseeded  DDN deuterium  discharges  at EAST  with  decreasing  drsep,  both  with  experimental  data  from  EAST  and SOLPS-ITER simulations [4]  .  Ne seeded discharges in H-mode from the 2019 EAST campaign are studied (heating power Pheat = 2.5 MW, plasma current Ip = 0.4 MA and toroidal field Bt = 2.4 T).  For the  first  time,  a  DDN  configuration  with  divertor  Te-feedback  for  the  Ne  puff  strength  was  attempted to achieve steady divertor conditions. A radiative fraction Prad/Pheat of up to 30% was achieved with Ne seeding while 10% is achieved without.  Ne in all cases was injected from the upper (active) outer  target  and  a  significant target temperature  drop  was  identified from  the Langmuir probes.  The effect of a DDN configuration however is limited as the upstream power scrape-off  width  (~0.5cm  [5])  is  significantly  smaller  compared  to  the  achieved  separation between the separatrices (drsep ~ 1.5 cm).  SOLPS-ITER simulations are being carried out to interpret the experimental results to understand the  influence  of  the  different  transport  types  in  the  SOL  for  a  dissipative  DDN divertor geometry with and without Ne seeding and C erosion. The model includes for the first time for EAST fluid drifts and edge currents in the SOL. SOLPS-ITER will be used to predict the performance of a Ne seeded EAST DN divertor (with drsep = 0) being closest to one of theconsidered DEMO divertor geometries. [1]  M.  Wischmeier,   et  al.,  J.  Nucl.  Mater.  22-29  (2015)  463; [2]  S.  Glöggler,  et  al.,  Nucl.  Fusion. 126031 (2019) 59 ; [3] H. Meyer, et al.,  Nucl. Fusion. 64-72 (2006) 46;  [4] S. Wiesen et al., J. Nucl. Mat. 480-484 (2015) 463 ; [5] T. Eich, et al., Nucl. Fusion  093031 (2013) 53
T2  - 24th International Conference on Plasma Surface Interactions in Controlled Fusion Devices (PSI 2020)
CY  - 25 Jan 2021 - 29 Jan 2021, virtuell (virtuell)
Y2  - 25 Jan 2021 - 29 Jan 2021
M2  - virtuell, virtuell
LB  - PUB:(DE-HGF)1
UR  - https://juser.fz-juelich.de/record/891500
ER  -