@article{3d2cc7e79c7b424084f2439db21cf5b9,
title = "Plasma flow measurements based on charge exchange recombination spectroscopy in the Wendelstein 7-X stellarator",
abstract = "The initial operation of neutral beams in Wendelstein 7-X enabled the first measurements of carbon (C6+) temperature and rotation with a multi-chord charge exchange recombination spectroscopy system. In this article we analyse the velocity measurements obtained with this system to infer the profiles of radial electric field, E r, and net parallel velocity of fully stripped carbon ions, V ‖. We include a general treatment of the flow geometry and the velocity corrections due to the energy dependence of the charge exchange cross section. The inverted profiles are compared with neoclassical calculations for various plasma conditions and two magnetic configurations. It is found that both the E r and V ‖ experimental profiles agree in sign and order of magnitude with the neoclassical expectations and reproduce the expected dependencies on plasma parameters and magnetic configuration, within the reduced dataset presented. However, quantitative differences with respect to the neoclassical profiles are observed above the estimated errors in various conditions.",
keywords = "magnetic confinement fusion, neoclassical theory, plasma flow, stellarator",
author = "Alonso, {J. A.} and Ford, {O. P.} and L. Van{\'o} and S. Akaslompolo and S. Buller and R. McDermott and Smith, {H. M.} and J. Baldzuhn and Beidler, {C. D.} and M. Beurskens and S. Bozhenkov and Brunner, {K. J.} and I. Calvo and D. Carralero and A. Dinklage and T. Estrada and G. Fuchert and J. Geiger and J. Knauer and A. Langenberg and Pablant, {N. A.} and E. Pasch and Poloskei, {P. Zs} and Velasco, {J. L.} and T. Windisch",
note = "Funding Information: J.A.A. and O.P.F. would like to acknowledge useful discussions with M. von Hellermann on the modelling of the CXRS signal composition. This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 and 2019–2020 under Grant Agreement No. 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. The work has been partially funded by the Ministerio de Ciencia, Innovaci{\'o}n y Universidades of Spain under project PGC2018-095307-B-I00. Publisher Copyright: {\textcopyright} 2022 IAEA, Vienna. | openaire: EC/H2020/633053/EU//EUROfusion ",
year = "2022",
month = sep,
doi = "10.1088/1741-4326/ac7e5b",
language = "English",
volume = "62",
pages = "1--17",
journal = "Nuclear Fusion",
issn = "0029-5515",
publisher = "Institute of Physics Publishing ",
number = "10",
}