TY  - CONF
AU  - Hwang, J. H.
AU  - Park, J.-S.
AU  - Pitts, R.
AU  - Lee, H. H.
AU  - Juhn, J.-W.
AU  - Jang, J.
AU  - Bak, J. G.
AU  - Wiesen, S.
AU  - Bernert, M.
AU  - Hong, S.-H.
AU  - Choe, W.
TI  - Experimental studies of H-mode divertor detachment with deuterium gas injection in KSTAR plasmas
M1  - FZJ-2021-01570
PY  - 2021
AB  - Experimental studies of H-mode divertor detachmentwith D2 injection in KSTARJ. H. Hwanga, J.-S. Parkb, R. Pittsb, H. H. Leec, J.-W. Juhnc, J. Jangc,J. G. Bakc,S. Wiesend, M. Bernerte,S.-H. Hongc, and W. Choea a KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Koreab ITEROrganization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex, FrancecNational Fusion Research Institute, 169-148 Gwahak-ro, Yuseong-gu,Daejeon 34133, KoreadForschungszentrum Jülich GmbH, Institut für Energie-und Klimaforschung -Plasmaphysik, D-52425 Jülich, GermanyeMax Planck Institute for Plasma Physics, Boltzmannstraße 2, 85748 Garching, Germanyhoo1021@kaist.ac.kr; wchoe@kaist.ac.krSince H-mode has beenregarded as a promising operating scenario for future tokamaks, it is important to get a good understanding of divertor detachment in H-mode plasmas.So far the extensive detachment studies in KSTAR focused on L-mode plasmas [1]. Therefore, H-mode detachmentstudies with pure deuterium fuelled discharges with no impurity gas seedingcan bethe baseline starting point for further complex studies of detachment under impurity injections or ELMcontrolled/suppressed 3D field configurations in KSTAR. In this study, the first signs of  H-mode  divertor  detachmentby  deuterium  gas  injectionin  KSTARwere  obtained  in electron density ramp discharges.The discharges in this study had Ip=0.7 MA and Bt= 1.8 T with ∇B-drift  directed  downward  into  the  lower  divertor.  The  total  NBI  heating  power  was 2.9-3.1  MW.  In  the  experiment,  the  outer  target  showed  a  partially  detached  regime  and  the inter-ELM  peak  particle  flux  was  reduced  significantly  by  a  factor  of  5  to  below 2.0x1022m-2s-1. At the inner target, particle flux roll-over occurred although there  was  not  significant reduction  of  the  inter-ELM  peak  particle  flux.The  line-integrated  density  rose  up  to about 6.0x1019m-3(fGW≈0.8) and further density increase for accessing pronounced detachment was failed by arriving at the H-mode density limit [2]. Theanomalous in/out detachment asymmetry in  which  the  outer  target  detaches  at  the  lower  core  density  than  the  inner  target  has  been observedin KSTAR L-mode plasmas [1]and it wasshown that the asymmetry was reproduced in KSTAR H-mode  plasmas.This  work  will act  as  reference for more  complex H-mode detachment studies to be pursued on KSTARand contribute to better understanding of physics behind divertor detachment.Experimental resultscould give several important constraints to theSOLPS-ITERmodelling  so  that  the  benchmarking  and  predictive  research  regarding KSTAR boundary plasmas will be possible.[1] J.-S. Park, et al., Nucl. Fusion 58 126033 (2018)[2] M. Bernert, et al., Plasma Phys. Control. Fusion 57 014038 (2015)
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/891504
ER  -