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Kubkowska M, Czarnecka A, Fornal T, Gruca M, Jabłoński S, Krawczyk N, Ryć L, Burhenn R, Buttenschön B, Geiger B, Grulke O, Langenberg A, Marchuk O, McCarthy KJ, Neuner U, Nicolai D, Pablant N, Schweer B, Thomsen H, Wegner T, Drews P, Hollfeld KP, Killer C, Krings T, Offermanns G, Satheeswaran G, Kunkel F. Plasma impurities observed by a pulse height analysis diagnostic during the divertor campaign of the Wendelstein 7-X stellarator. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:10F111. [PMID: 30399723 DOI: 10.1063/1.5038850] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Accepted: 07/16/2018] [Indexed: 06/08/2023]
Abstract
The paper reports on the optimization process of the soft X-ray pulse height analyzer installed on the Wendelstein 7-X (W7-X) stellarator. It is a 3-channel system that records X-ray spectra in the range from 0.6 to 19.6 keV. X-ray spectra, with a temporal and spatial resolution of 100 ms and 2.5 cm (depending on selected slit sizes), respectively, are line integrated along a line-of-sight that crosses near to the plasma center. In the second W7-X operation phase with a carbon test divertor unit, light impurities, e.g., carbon and oxygen, were observed as well as mid- to high-Z elements, e.g., sulfur, chlorine, chromium, manganese, iron, and nickel. In addition, X-ray lines from several tracer elements have been observed after the laser blow-off injection of different impurities, e.g., silicon, titanium, and iron, and during discharges with prefill or a gas puff of neon or argon. These measurements were achieved by optimizing light absorber-foil selection, which defines the detected energy range, and remotely controlled pinhole size, which defines photon flux. The identification of X-ray lines was confirmed by other spectroscopic diagnostics, e.g., by the High-Efficiency XUV Overview Spectrometer, HEXOS, and high-resolution X-ray imaging spectrometer, HR-XIS.
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Affiliation(s)
- M Kubkowska
- Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland
| | - A Czarnecka
- Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland
| | - T Fornal
- Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland
| | - M Gruca
- Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland
| | - S Jabłoński
- Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland
| | - N Krawczyk
- Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland
| | - L Ryć
- Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland
| | - R Burhenn
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - B Buttenschön
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - B Geiger
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - O Grulke
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - A Langenberg
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - O Marchuk
- Forschungszentrum, 52425 Juelich, Germany
| | - K J McCarthy
- Laboratorio Nacional de Fusion, CIEMAT, Avenida Complutense, Madrid, Spain
| | - U Neuner
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - D Nicolai
- Forschungszentrum, 52425 Juelich, Germany
| | - N Pablant
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA
| | - B Schweer
- Forschungszentrum, 52425 Juelich, Germany
| | - H Thomsen
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - Th Wegner
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - P Drews
- Forschungszentrum, 52425 Juelich, Germany
| | | | - C Killer
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - Th Krings
- Forschungszentrum, 52425 Juelich, Germany
| | | | | | - F Kunkel
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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