| Autor: |
Kubkowska M; Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland., Czarnecka A; Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland., Fornal T; Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland., Gruca M; Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland., Jabłoński S; Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland., Krawczyk N; Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland., Ryć L; Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland., Burhenn R; Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany., Buttenschön B; Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany., Geiger B; Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany., Grulke O; Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany., Langenberg A; Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany., Marchuk O; Forschungszentrum, 52425 Juelich, Germany., McCarthy KJ; Laboratorio Nacional de Fusion, CIEMAT, Avenida Complutense, Madrid, Spain., Neuner U; Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany., Nicolai D; Forschungszentrum, 52425 Juelich, Germany., Pablant N; Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA., Schweer B; Forschungszentrum, 52425 Juelich, Germany., Thomsen H; Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany., Wegner T; Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany., Drews P; Forschungszentrum, 52425 Juelich, Germany., Hollfeld KP; Forschungszentrum, 52425 Juelich, Germany., Killer C; Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany., Krings T; Forschungszentrum, 52425 Juelich, Germany., Offermanns G; Forschungszentrum, 52425 Juelich, Germany., Satheeswaran G; Forschungszentrum, 52425 Juelich, Germany., Kunkel F; Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany. |
| Abstrakt: |
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. |
