Dependence of upstream SOL density shoulder on divertor neutral pressure observed in L-mode and H-mode plasmas in the EAST superconducting tokamak

被引：15

作者：

Yan, N. ^{[1
]}

Chen, L. ^{[1
]}

Xu, G. S. ^{[1
]}

Wu, X. Q. ^{[1
]}

Liu, S. C. ^{[1
]}

Wang, Y. F. ^{[1
]}

Meng, L. Y. ^{[1
,2
]}

Hu, G. H. ^{[1
]}

Zhao, N. ^{[1
]}

Lan, H. ^{[1
]}

Naulin, V. ^{[3
]}

Nielsen, A. H. ^{[3
]}

Juul Rasmussen, J. ^{[3
]}

Li, K. D. ^{[1
]}

Wang, L. ^{[1
,4
]}

Yang, Q. Q. ^{[1
]}

Li, M. H. ^{[1
]}

Ye, Y. ^{[1
]}

Ding, R. ^{[1
]}

Tao, Y. Q. ^{[1
,2
]}

Qian, Y. Z. ^{[1
]}

Hou, J. L. ^{[1
]}

Liu, X. ^{[1
]}

Liu, J. B. ^{[1
]}

机构：

[1] Chinese Acad Sci, Inst Plasma Phys, Hefei 230031, Peoples R China

[2] Univ Sci & Technol China, Hefei 230026, Peoples R China

[3] Tech Univ Denmark, Dept Phys, DK-2800 Lyngby, Denmark

[4] Dalian Univ Technol, Dalian 116024, Peoples R China

来源：

NUCLEAR FUSION | 2021年 / 61卷 / 07期

基金：

中国国家自然科学基金;

关键词：

scrape-off-layer; density shoulder; tokamak; divertor; neutral recycling; SCRAPE-OFF-LAYER; TRANSPORT; FLUCTUATIONS; PHYSICS;

D O I：

10.1088/1741-4326/abfe47

中图分类号：

O35 [流体力学]; O53 [等离子体物理学];

学科分类号：

070204 ; 080103 ; 080704 ;

摘要：

Upstream density profiles in the scrape-off layer (SOL) have been examined in low-confinement mode (L-mode) and high-confinement mode (H-mode) plasmas in the EAST superconducting tokamak. A weak density shoulder forms in the near SOL region in upper single-null configurations when the neutral pressure measured at the lower divertor exceeds a threshold value of 2 x 10(-2) Pa in L-mode plasmas. When the neutral pressure is below this threshold, the weak density shoulder is absent and the sidebands of the lower hybrid waves associated with SOL parametric instabilities are reduced. Active detachment control with neon-deuterium seeding demonstrate that the weak density shoulder can form before the onset of the outer divertor detachment as long as the neutral pressure is above the threshold. Furthermore, no remarkable expansion of a shoulder is observed during divertor detachment, suggesting that divertor detachment is not a necessary condition for the formation or growth of a density shoulder. Through the increase in neutral pressure in the lower divertor by an order of magnitude, the weak shoulder was observed to expand into the far SOL and reach the leading edge of the limiter. The results in L-mode discharges identified the neutral pressure in the lower divertor as a primary factor for the formation of an SOL density shoulder in the upper single-null discharges. For the type-I ELMy H-mode plasmas, a similar density shoulder was detected during the inter-ELM phase when the neutral pressure in the lower divertor exceeded a threshold value of 4 x 10(-2) Pa. On the other hand, the shoulder was absent when the divertor neutral pressure went below this threshold even though the plasma discharge was conducted with a higher core line-averaged density and divertor collisionality. This is consistent with the observations in L-mode plasmas. The neutral particle ionization of the working gas is thus believed to play a key role during the formation of the SOL density shoulder in the EAST tokamak.

引用

页数：15

共 46 条

[1] Neutral density estimation in the ASDEX upgrade divertor from deuterium emissivity measurements during detachment and shoulder formation [J].

Agostini, M. ;

Vianello, N. ;

Carraro, L. ;

Carralero, D. ;

Cavedon, M. ;

Dux, R. ;

Naulin, V ;

Spolaore, M. ;

Wolfrum, E. .

PLASMA PHYSICS AND CONTROLLED FUSION, 2019, 61 (11)

[2] Observation of Efficient Lower Hybrid Current Drive at High Density in Diverted Plasmas on the Alcator C-Mod Tokamak [J].

Baek, S. G. ;

Wallace, G. M. ;

Bonoli, P. T. ;

Brunner, D. ;

Faust, I. C. ;

Hubbard, A. E. ;

Hughes, J. W. ;

LaBombard, B. ;

Parker, R. R. ;

Porkolab, M. ;

Shiraiwa, S. ;

Wukitch, S. .

PHYSICAL REVIEW LETTERS, 2018, 121 (05)

[3] A study on the density shoulder formation in the SOL of H-mode plasmas [J].

Carralero, D. ;

Madsen, J. ;

Artene, S. A. ;

Bernert, M. ;

Birkenmeier, G. ;

Eich, T. ;

Fuchert, G. ;

Laggner, F. ;

Naulin, V. ;

Manz, P. ;

Vianello, N. ;

Wolfrum, E. .

NUCLEAR MATERIALS AND ENERGY, 2017, 12 :1189-1193

[4] Recent progress towards a quantitative description of filamentary SOL transport [J].

Carralero, D. ;

Siccinio, M. ;

Komm, M. ;

Artene, S. A. ;

D'Isa, F. A. ;

Adamek, J. ;

Aho-Mantila, L. ;

Birkenmeier, G. ;

Brix, M. ;

Fuchert, G. ;

Groth, M. ;

Lunt, T. ;

Manz, P. ;

Madsen, J. ;

Marsen, S. ;

Mueller, H. W. ;

Stroth, U. ;

Sun, H. J. ;

Vianello, N. ;

Wischmeier, M. ;

Wolfrum, E. ;

Abduallev, S. ;

Abhangi, M. ;

Abreu, P. ;

Afzal, M. ;

Aggarwal, K. M. ;

Ahlgren, T. ;

Ahn, J. H. ;

Aho-Mantila, L. ;

Aiba, N. ;

Airila, M. ;

Albanese, R. ;

Aldred, V. ;

Alegre, D. ;

Alessi, E. ;

Aleynikov, P. ;

Alfier, A. ;

Alkseev, A. ;

Allinson, M. ;

Alper, B. ;

Alves, E. ;

Ambrosino, G. ;

Ambrosino, R. ;

Amicucci, L. ;

Amosov, V. ;

Sunden, E. Andersson ;

Angelone, M. ;

Anghel, M. ;

Angioni, C. ;

Appel, L. .

NUCLEAR FUSION, 2017, 57 (05)

[5] Experimental Validation of a Filament Transport Model in Turbulent Magnetized Plasmas [J].

Carralero, D. ;

Manz, P. ;

Aho-Mantila, L. ;

Birkenmeier, G. ;

Brix, M. ;

Groth, M. ;

Mueller, H. W. ;

Stroth, U. ;

Vianello, N. ;

Wolfrum, E. ;

Abhangi, M. ;

Abreu, P. ;

Aftanas, M. ;

Afzal, M. ;

Aggarwal, K. M. ;

Aho-Mantila, L. ;

Ahonen, E. ;

Aints, M. ;

Airila, M. ;

Albanese, R. ;

Alegre, D. ;

Alessi, E. ;

Aleynikov, P. ;

Alfier, A. ;

Alkseev, A. ;

Allan, P. ;

Almaviva, S. ;

Alonso, A. ;

Alper, B. ;

Alsworth, I. ;

Alves, D. ;

Ambrosino, G. ;

Ambrosino, R. ;

Amosov, V. ;

Andersson, F. ;

Andersson Sunden, E. ;

Angelone, M. ;

Anghel, A. ;

Anghel, M. ;

Angioni, C. ;

Appel, L. ;

Apruzzese, G. ;

Arena, P. ;

Ariola, M. ;

Arnichand, H. ;

Arnoux, G. ;

Arshad, S. ;

Ash, A. ;

Asp, E. ;

Asunta, O. .

PHYSICAL REVIEW LETTERS, 2015, 115 (21)

[6] Implications of high density operation on SOL transport: A multimachine investigation [J].

Carralero, D. ;

Mueller, H. W. ;

Groth, M. ;

Komm, M. ;

Adamek, J. ;

Birkenmeier, G. ;

Brix, M. ;

Janky, F. ;

Hacek, P. ;

Marsen, S. ;

Reimold, F. ;

Silva, C. ;

Stroth, U. ;

Wischmeier, M. ;

Wolfrum, E. .

JOURNAL OF NUCLEAR MATERIALS, 2015, 463 :123-127

[7] An experimental investigation of the high density transition of the scrape-off layer transport in ASDEX Upgrade [J].

Carralero, D. ;

Birkenmeier, G. ;

Mueller, H. W. ;

Manz, P. ;

deMarne, P. ;

Mueller, S. H. ;

Reimold, F. ;

Stroth, U. ;

Wischmeier, M. ;

Wolfrum, E. .

NUCLEAR FUSION, 2014, 54 (12)

[8] Cross-field blob transport in tokamak scrape-off-layer plasmas [J].

D'Ippolito, DA ;

Myra, JR ;

Krasheninnikov, SI .

PHYSICS OF PLASMAS, 2002, 9 (01) :222-233

[9] Investigations of LHW-plasma coupling and current drive at high density related to H-mode experiments in EAST [J].

Ding, B. J. ;

Li, Y. C. ;

Zhang, L. ;

Li, M. H. ;

Wei, W. ;

Kong, E. H. ;

Wang, M. ;

Xu, H. D. ;

Wang, S. L. ;

Xu, G. S. ;

Zhao, L. M. ;

Hu, H. C. ;

Jia, H. ;

Cheng, M. ;

Yang, Y. ;

Liu, L. ;

Zhao, H. L. ;

Peysson, Y. ;

Decker, J. ;

Goniche, M. ;

Amicucci, L. ;

Cesario, R. ;

Tuccillo, A. A. ;

Baek, S. G. ;

Parker, R. ;

Bonoli, P. T. ;

Paoletti, F. ;

Yang, C. ;

Shan, J. F. ;

Liu, F. K. ;

Zhao, Y. P. ;

Gong, X. Z. ;

Hu, L. Q. ;

Gao, X. ;

Wan, B. N. ;

Li, J. G. .

NUCLEAR FUSION, 2015, 55 (09)

[10] Fluctuations and transport in the TCV scrape-off layer [J].

Garcia, O. E. ;

Horacek, J. ;

Pitts, R. A. ;

Nielsen, A. H. ;

Fundamenski, W. ;

Naulin, V. ;

Rasmussen, J. Juul .

NUCLEAR FUSION, 2007, 47 (07) :667-676

← 1 2 3 4 5 →