skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Doppler coherence imaging of divertor and SOL flows in ASDEX upgrade and Wendelstein 7-X

Journal Article · · Plasma Physics and Controlled Fusion

Measurement of ion dynamics is of great importance to the study of plasma exhaust and impurity particle flows in the scrape-off-layer (SOL) and divertor in magnetic confinement experiments. Doppler coherence imaging spectroscopy (CIS) is a passive optical diagnostic that produces 2D images of line-integrated ion flow velocity. Doppler CIS flow measurements of neutral deuterium and impurities were conducted for the first time in the divertor of the medium-sized tokamak experiment ASDEX Upgrade. A detailed sightline, emission and magnetic field analysis was undertaken to identify location and direction of flows. Under the assumption of toroidal axisymmetry, they revealed mainly parallel impurity flows in the proximity of the X-point and target plates on the order of 20 km s-1. Two Doppler CIS systems are currently set up for the optimized stellarator Wendelstein 7-X (W7-X). With this being said, the main task of this diagnostic will be the measurement of impurity ion flows in one of the island divertors of W7-X. EMC3-EIRENE simulations have been carried out to estimate the flow behaviour in the W7-X SOL.

Research Organization:
Univ. of Wisconsin, Madison, WI (United States)
Sponsoring Organization:
USDOE
Contributing Organization:
ASDEX Upgrade Team; Wendelstein 7-X Team; Eurofusion MST1 team
Grant/Contract Number:
SC0014210
OSTI ID:
1499869
Journal Information:
Plasma Physics and Controlled Fusion, Vol. 60, Issue 8; ISSN 0741-3335
Publisher:
IOP ScienceCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 12 works
Citation information provided by
Web of Science

References (25)

Impurity flow measurements at DIII-D using a coherence imaging spectrometer journal July 2013
Transport-driven Scrape-Off-Layer flows and the boundary conditions imposed at the magnetic separatrix in a tokamak plasma journal September 2004
Physics of island divertors as highlighted by the example of W7-AS journal July 2006
The role of friction in SOL pressure balance in Alcator C-Mod journal March 1999
Coherence imaging spectro-polarimetry for magnetic fusion diagnostics journal July 2010
Physical Aspects and Design of the Wendelstein 7-X Divertor journal September 2004
The divertor program in stellarators journal October 2002
Phase shift formulas in uniaxial media: an application to waveplates journal January 2010
Interpretations of the impact of cross-field drifts on divertor flows in DIII-D with UEDGE journal August 2017
Understanding the SOL flow in L-mode plasma on divertor tokamaks, and its influence on the plasma transport journal June 2007
Imaging charge exchange recombination spectroscopy on the TEXTOR tokamak journal November 2010
A new experimental classification of divertor detachment in ASDEX Upgrade journal November 2013
Coherence Imaging of Flows in the DIII-D Divertor journal March 2011
Doppler coherence imaging and tomography of flows in tokamak plasmas (invited) journal October 2010
Physics optimization of stellarators journal March 1992
2D distribution of hydrogen/impurity radiation and flow formation in stochastic layer during detachment transition in LHD journal August 2017
Comparison between stellarator and tokamak divertor transport journal January 2011
Coherence imaging of scrape-off-layer and divertor impurity flows in the Mega Amp Spherical Tokamak (invited) journal November 2014
Coherence imaging for ion temperature and flow measurements in a low-temperature helicon plasma source journal January 2016
Novel scanning interferometer for two‐dimensional plasma density measurements journal March 1990
Partial detachment of high power discharges in ASDEX Upgrade journal April 2015
Synthetic plasma edge diagnostics for EMC3-EIRENE, highlighted for Wendelstein 7-X journal September 2016
The Plasma Boundary of Magnetic Fusion Devices book January 2000
Absolute calibration of Doppler coherence imaging velocity images journal August 2017
The Plasma Boundary of Magnetic Fusion Devices journal January 2001

Cited By (4)

Direct measurements of counter-streaming flows in a low-shear stellarator magnetic island topology journal September 2019
Roadmap on photonic, electronic and atomic collision physics: II. Electron and antimatter interactions journal August 2019
First demonstration of radiative power exhaust with impurity seeding in the island divertor at Wendelstein 7-X journal August 2019
Coherence imaging spectroscopy at Wendelstein 7-X for impurity flow measurements journal January 2020