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Title: Prospects of X-ray imaging spectrometers for impurity transport: Recent results from the stellarator Wendelstein 7-X (invited)

Abstract

This paper reports on the design and the performance of the recently upgraded X-ray imaging spectrometer systems, X-ray imaging crystal spectrometer and high resolution X-ray imaging spectrometer, installed at the optimized stellarator Wendelstein 7-X. High resolution spectra of highly ionized, He-like Si, Ar, Ti, and Fe as well as H-like Ar have been observed. A cross comparison of ion and electron temperature profiles derived from a spectral fit and tomographic inversion of Ar and Fe spectra shows a reasonable match with both the spectrometers. The also measured impurity density profiles of Ar and Fe have peaked densities at radial positions that are in qualitative agreement with the expectations from the He-like impurity fractional abundances, given the measured temperature profiles. In conclusion, repeated measurements of impurity decay times have been demonstrated with an accuracy of 1 ms via injection of non-recycling Ti, Fe, and Mo impurities using a laser blow-off system.

Authors:
 [1]; ORCiD logo [2]; ORCiD logo [1];  [3]; ORCiD logo [4];  [1];  [1];  [1]; ORCiD logo [1];  [1];  [5];  [1]; ORCiD logo [1]; ORCiD logo [6];  [6];  [6];  [6];  [6]; ORCiD logo [6];  [6] more »;  [1];  [1]; ORCiD logo [7];  [1]; ORCiD logo [1] « less
  1. Max-Planck-Inst. fur Plasmaphysik, Greifswald (Germany)
  2. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  3. Auburn Univ., AL (United States)
  4. Technical Univ. of Denmark, Lyngby (Denmark). Dept. of Physics
  5. Max-Planck-Inst. fur Plasmaphysik, Greifswald (Germany); Technical Univ. of Denmark, Lyngby (Denmark). Dept. of Physics
  6. Forschungszentrum Julich (Germany). Inst. fur Energie- und Klimaforschung (IEK)-Plasmaphysik
  7. Research Centre for Energy, Environment and Technology (CIEMAT), Madrid (Spain). Asociacion EURATOM-CIEMAT, Lab. Nacional de Fusion
Publication Date:
Research Org.:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Org.:
USDOE
Contributing Org.:
W7-X Team
OSTI Identifier:
1473875
Grant/Contract Number:  
633053
Resource Type:
Accepted Manuscript
Journal Name:
Review of Scientific Instruments
Additional Journal Information:
Journal Volume: 89; Journal Issue: 10; Journal ID: ISSN 0034-6748
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
47 OTHER INSTRUMENTATION

Citation Formats

Langenberg, A., Pablant, N. A., Wegner, Th., Traverso, P., Marchuk, O., Bräuer, T., Geiger, B., Fuchert, G., Bozhenkov, S., Pasch, E., Grulke, O., Kunkel, F., Killer, C., Nicolai, D., Satheeswaran, G., Hollfeld, K. P., Schweer, B., Krings, T., Drews, P., Offermanns, G., Pavone, A., Svensson, J., Alonso, J. A., Burhenn, R., and Wolf, R. C. Prospects of X-ray imaging spectrometers for impurity transport: Recent results from the stellarator Wendelstein 7-X (invited). United States: N. p., 2018. Web. doi:10.1063/1.5036536.
Langenberg, A., Pablant, N. A., Wegner, Th., Traverso, P., Marchuk, O., Bräuer, T., Geiger, B., Fuchert, G., Bozhenkov, S., Pasch, E., Grulke, O., Kunkel, F., Killer, C., Nicolai, D., Satheeswaran, G., Hollfeld, K. P., Schweer, B., Krings, T., Drews, P., Offermanns, G., Pavone, A., Svensson, J., Alonso, J. A., Burhenn, R., & Wolf, R. C. Prospects of X-ray imaging spectrometers for impurity transport: Recent results from the stellarator Wendelstein 7-X (invited). United States. doi:10.1063/1.5036536.
Langenberg, A., Pablant, N. A., Wegner, Th., Traverso, P., Marchuk, O., Bräuer, T., Geiger, B., Fuchert, G., Bozhenkov, S., Pasch, E., Grulke, O., Kunkel, F., Killer, C., Nicolai, D., Satheeswaran, G., Hollfeld, K. P., Schweer, B., Krings, T., Drews, P., Offermanns, G., Pavone, A., Svensson, J., Alonso, J. A., Burhenn, R., and Wolf, R. C. Fri . "Prospects of X-ray imaging spectrometers for impurity transport: Recent results from the stellarator Wendelstein 7-X (invited)". United States. doi:10.1063/1.5036536. https://www.osti.gov/servlets/purl/1473875.
@article{osti_1473875,
title = {Prospects of X-ray imaging spectrometers for impurity transport: Recent results from the stellarator Wendelstein 7-X (invited)},
author = {Langenberg, A. and Pablant, N. A. and Wegner, Th. and Traverso, P. and Marchuk, O. and Bräuer, T. and Geiger, B. and Fuchert, G. and Bozhenkov, S. and Pasch, E. and Grulke, O. and Kunkel, F. and Killer, C. and Nicolai, D. and Satheeswaran, G. and Hollfeld, K. P. and Schweer, B. and Krings, T. and Drews, P. and Offermanns, G. and Pavone, A. and Svensson, J. and Alonso, J. A. and Burhenn, R. and Wolf, R. C.},
abstractNote = {This paper reports on the design and the performance of the recently upgraded X-ray imaging spectrometer systems, X-ray imaging crystal spectrometer and high resolution X-ray imaging spectrometer, installed at the optimized stellarator Wendelstein 7-X. High resolution spectra of highly ionized, He-like Si, Ar, Ti, and Fe as well as H-like Ar have been observed. A cross comparison of ion and electron temperature profiles derived from a spectral fit and tomographic inversion of Ar and Fe spectra shows a reasonable match with both the spectrometers. The also measured impurity density profiles of Ar and Fe have peaked densities at radial positions that are in qualitative agreement with the expectations from the He-like impurity fractional abundances, given the measured temperature profiles. In conclusion, repeated measurements of impurity decay times have been demonstrated with an accuracy of 1 ms via injection of non-recycling Ti, Fe, and Mo impurities using a laser blow-off system.},
doi = {10.1063/1.5036536},
journal = {Review of Scientific Instruments},
number = 10,
volume = 89,
place = {United States},
year = {2018},
month = {7}
}

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Cited by: 8 works
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Figures / Tables:

Fig. 1 Fig. 1: The movable (x and y direction) and rotatable (around z axis) crystal table of the HR-XIS diagnostic with its 8 crystal holders for installation of various crystals for X-ray diffraction. The crystal table diameter measures 310 mm.

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    Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.