The effects of magnetic topology on the scrape-off layer turbulence transport in the first divertor plasma operation of Wendelstein 7-X using a new combined probe

S. C. Liu; Y. Liang; P. Drews; C. Killer; A. Knieps; G. S. Xu; H. Q. Wang; N. Yan; X. Han; D. Höschen; A. Krämer-Flecken; D. Nicolai; G. Satheeswaran; K. Hammond; J. Q. Cai; A. Charl; J. Cosfeld; G. Fuchert; Y. Gao; J. Geiger; O. Grulke; M. Henkel; M. Hirsch; U. Hoefel; R. König; Y. Li; O. Neubauer; E. Pasch; K. Rahbarnia; M. Rack; N. Sandri; S. Sereda; B. Schweer; E. H. Wang; S. Xu; X. Gao

doi:10.1088/1741-4326/ab0d29

The effects of magnetic topology on the scrape-off layer turbulence transport in the first divertor plasma operation of Wendelstein 7-X using a new combined probe

S. C. Liu
, Y. Liang
, P. Drews
, C. Killer
, A. Knieps
, G. S. Xu
, H. Q. Wang
, N. Yan
, X. Han
, D. Höschen
, A. Krämer-Flecken
, D. Nicolai
, G. Satheeswaran
, K. Hammond
, J. Q. Cai
, A. Charl
, J. Cosfeld
, G. Fuchert
, Y. Gao
, J. Geiger

O. Grulke, M. Henkel, M. Hirsch, U. Hoefel, R. König, Y. Li, O. Neubauer, E. Pasch, K. Rahbarnia, M. Rack, N. Sandri, S. Sereda, B. Schweer, E. H. Wang, S. Xu, X. Gao

Research output: Contribution to journal › Article › peer-review

Abstract

Wendelstein 7-X (W7-X) was operated successfully with the first divertor plasma in the operation phase 1.2a (OP1.2a). A new combined probe head, developed and installed on the multiple-purpose manipulator, is able to measure the edge plasma profiles (T_e, n_e, φf,M_∥), variation of magnetic field, poloidal and radial turbulence structures. The scrape-off layer (SOL) plasma parameters in two magnetic configurations (standard and high mirror) are in good agreement with the magnetic island structure and the field line connection length calculated by the field line tracer. In both the standard and high mirror configurations, the radial turbulent heat flux and particle flux have strong dependence on the local magnetic topology, revealing two distinct transport patterns: a broadband turbulence dominant region in the outer SOL and a low frequency dominant region in the inner SOL. In the standard divertor configuration, the broadband turbulence with a frequency range of 40-120 kHz is located near the island center along the probe path, leading to outward transport. These broadband fluctuations propagate with a velocity of 2.3-4.4 km s?1 poloidally along the ion diamagnetic drift direction in the plasma frame, with kθρs close to 0.1. The large radial transport induced by the broadband turbulence is accompanied by a steep electron density gradient. The low frequency (5-30 kHz) dominant transport exhibits obvious intermittent structure. Some statistical techniques are applied to the characterization of the intermittent transport.

Original language	American English
Article number	066001
Journal	Nuclear Fusion
Volume	59
Issue number	6
DOIs	https://doi.org/10.1088/1741-4326/ab0d29
State	Published - Apr 24 2019
Externally published	Yes

ASJC Scopus subject areas

Nuclear and High Energy Physics
Condensed Matter Physics

Keywords

Island divertor
Langmuir probe
SOL turbulence
Wendelstein 7-X
stellarator
turbulence transport

Access to Document

10.1088/1741-4326/ab0d29

Cite this

Liu, S. C., Liang, Y., Drews, P., Killer, C., Knieps, A., Xu, G. S., Wang, H. Q., Yan, N., Han, X., Höschen, D., Krämer-Flecken, A., Nicolai, D., Satheeswaran, G., Hammond, K., Cai, J. Q., Charl, A., Cosfeld, J., Fuchert, G., Gao, Y., ... Gao, X. (2019). The effects of magnetic topology on the scrape-off layer turbulence transport in the first divertor plasma operation of Wendelstein 7-X using a new combined probe. Nuclear Fusion, 59(6), Article 066001. https://doi.org/10.1088/1741-4326/ab0d29

@article{4d74faf6db414fc8876f02b0a4975b7f,

title = "The effects of magnetic topology on the scrape-off layer turbulence transport in the first divertor plasma operation of Wendelstein 7-X using a new combined probe",

abstract = "Wendelstein 7-X (W7-X) was operated successfully with the first divertor plasma in the operation phase 1.2a (OP1.2a). A new combined probe head, developed and installed on the multiple-purpose manipulator, is able to measure the edge plasma profiles (Te, ne, φf,M∥), variation of magnetic field, poloidal and radial turbulence structures. The scrape-off layer (SOL) plasma parameters in two magnetic configurations (standard and high mirror) are in good agreement with the magnetic island structure and the field line connection length calculated by the field line tracer. In both the standard and high mirror configurations, the radial turbulent heat flux and particle flux have strong dependence on the local magnetic topology, revealing two distinct transport patterns: a broadband turbulence dominant region in the outer SOL and a low frequency dominant region in the inner SOL. In the standard divertor configuration, the broadband turbulence with a frequency range of 40-120 kHz is located near the island center along the probe path, leading to outward transport. These broadband fluctuations propagate with a velocity of 2.3-4.4 km s?1 poloidally along the ion diamagnetic drift direction in the plasma frame, with kθρs close to 0.1. The large radial transport induced by the broadband turbulence is accompanied by a steep electron density gradient. The low frequency (5-30 kHz) dominant transport exhibits obvious intermittent structure. Some statistical techniques are applied to the characterization of the intermittent transport.",

keywords = "Island divertor, Langmuir probe, SOL turbulence, Wendelstein 7-X, stellarator, turbulence transport",

author = "Liu, \{S. C.\} and Y. Liang and P. Drews and C. Killer and A. Knieps and Xu, \{G. S.\} and Wang, \{H. Q.\} and N. Yan and X. Han and D. H{\"o}schen and A. Kr{\"a}mer-Flecken and D. Nicolai and G. Satheeswaran and K. Hammond and Cai, \{J. Q.\} and A. Charl and J. Cosfeld and G. Fuchert and Y. Gao and J. Geiger and O. Grulke and M. Henkel and M. Hirsch and U. Hoefel and R. K{\"o}nig and Y. Li and O. Neubauer and E. Pasch and K. Rahbarnia and M. Rack and N. Sandri and S. Sereda and B. Schweer and Wang, \{E. H.\} and S. Xu and X. Gao",

note = "Publisher Copyright: {\textcopyright} EURATOM 2019 Printed in the UK.",

year = "2019",

month = apr,

day = "24",

doi = "10.1088/1741-4326/ab0d29",

language = "American English",

volume = "59",

journal = "Nuclear Fusion",

issn = "0029-5515",

publisher = "IOP Publishing Ltd.",

number = "6",

}

Liu, SC, Liang, Y, Drews, P, Killer, C, Knieps, A, Xu, GS, Wang, HQ, Yan, N, Han, X, Höschen, D, Krämer-Flecken, A, Nicolai, D, Satheeswaran, G, Hammond, K, Cai, JQ, Charl, A, Cosfeld, J, Fuchert, G, Gao, Y, Geiger, J, Grulke, O, Henkel, M, Hirsch, M, Hoefel, U, König, R, Li, Y, Neubauer, O, Pasch, E, Rahbarnia, K, Rack, M, Sandri, N, Sereda, S, Schweer, B, Wang, EH, Xu, S & Gao, X 2019, 'The effects of magnetic topology on the scrape-off layer turbulence transport in the first divertor plasma operation of Wendelstein 7-X using a new combined probe', Nuclear Fusion, vol. 59, no. 6, 066001. https://doi.org/10.1088/1741-4326/ab0d29

TY - JOUR

T1 - The effects of magnetic topology on the scrape-off layer turbulence transport in the first divertor plasma operation of Wendelstein 7-X using a new combined probe

AU - Liu, S. C.

AU - Liang, Y.

AU - Drews, P.

AU - Killer, C.

AU - Knieps, A.

AU - Xu, G. S.

AU - Wang, H. Q.

AU - Yan, N.

AU - Han, X.

AU - Höschen, D.

AU - Krämer-Flecken, A.

AU - Nicolai, D.

AU - Satheeswaran, G.

AU - Hammond, K.

AU - Cai, J. Q.

AU - Charl, A.

AU - Cosfeld, J.

AU - Fuchert, G.

AU - Gao, Y.

AU - Geiger, J.

AU - Grulke, O.

AU - Henkel, M.

AU - Hirsch, M.

AU - Hoefel, U.

AU - König, R.

AU - Li, Y.

AU - Neubauer, O.

AU - Pasch, E.

AU - Rahbarnia, K.

AU - Rack, M.

AU - Sandri, N.

AU - Sereda, S.

AU - Schweer, B.

AU - Wang, E. H.

AU - Xu, S.

AU - Gao, X.

PY - 2019/4/24

Y1 - 2019/4/24

N2 - Wendelstein 7-X (W7-X) was operated successfully with the first divertor plasma in the operation phase 1.2a (OP1.2a). A new combined probe head, developed and installed on the multiple-purpose manipulator, is able to measure the edge plasma profiles (Te, ne, φf,M∥), variation of magnetic field, poloidal and radial turbulence structures. The scrape-off layer (SOL) plasma parameters in two magnetic configurations (standard and high mirror) are in good agreement with the magnetic island structure and the field line connection length calculated by the field line tracer. In both the standard and high mirror configurations, the radial turbulent heat flux and particle flux have strong dependence on the local magnetic topology, revealing two distinct transport patterns: a broadband turbulence dominant region in the outer SOL and a low frequency dominant region in the inner SOL. In the standard divertor configuration, the broadband turbulence with a frequency range of 40-120 kHz is located near the island center along the probe path, leading to outward transport. These broadband fluctuations propagate with a velocity of 2.3-4.4 km s?1 poloidally along the ion diamagnetic drift direction in the plasma frame, with kθρs close to 0.1. The large radial transport induced by the broadband turbulence is accompanied by a steep electron density gradient. The low frequency (5-30 kHz) dominant transport exhibits obvious intermittent structure. Some statistical techniques are applied to the characterization of the intermittent transport.

AB - Wendelstein 7-X (W7-X) was operated successfully with the first divertor plasma in the operation phase 1.2a (OP1.2a). A new combined probe head, developed and installed on the multiple-purpose manipulator, is able to measure the edge plasma profiles (Te, ne, φf,M∥), variation of magnetic field, poloidal and radial turbulence structures. The scrape-off layer (SOL) plasma parameters in two magnetic configurations (standard and high mirror) are in good agreement with the magnetic island structure and the field line connection length calculated by the field line tracer. In both the standard and high mirror configurations, the radial turbulent heat flux and particle flux have strong dependence on the local magnetic topology, revealing two distinct transport patterns: a broadband turbulence dominant region in the outer SOL and a low frequency dominant region in the inner SOL. In the standard divertor configuration, the broadband turbulence with a frequency range of 40-120 kHz is located near the island center along the probe path, leading to outward transport. These broadband fluctuations propagate with a velocity of 2.3-4.4 km s?1 poloidally along the ion diamagnetic drift direction in the plasma frame, with kθρs close to 0.1. The large radial transport induced by the broadband turbulence is accompanied by a steep electron density gradient. The low frequency (5-30 kHz) dominant transport exhibits obvious intermittent structure. Some statistical techniques are applied to the characterization of the intermittent transport.

KW - Island divertor

KW - Langmuir probe

KW - SOL turbulence

KW - Wendelstein 7-X

KW - stellarator

KW - turbulence transport

UR - https://www.scopus.com/pages/publications/85067582948

UR - https://www.scopus.com/pages/publications/85067582948#tab=citedBy

U2 - 10.1088/1741-4326/ab0d29

DO - 10.1088/1741-4326/ab0d29

M3 - Article

SN - 0029-5515

VL - 59

JO - Nuclear Fusion

JF - Nuclear Fusion

IS - 6

M1 - 066001

ER -

The effects of magnetic topology on the scrape-off layer turbulence transport in the first divertor plasma operation of Wendelstein 7-X using a new combined probe

Abstract

ASJC Scopus subject areas

Keywords

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