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Title: Pellet fueling experiments in Wendelstein 7-X

Abstract

During the two most recent experimental campaigns in the advanced stellarator Wendelstein 7-X (W7-X) (Klinger et al 2017 Plasma Phys. Control. Fusion 59 014018; Bosch et al 2017 Nucl. Fusion 57 116015; Wolf et al 2017 Nucl. Fusion 57 102020; Pedersen et al 2017 Phys. Plasmas 24 0555030) hydrogen ice pellet injection was performed for the first time. In order to investigate the potential of pellet fueling in W7-X and to study the particle deposition in a large stellarator, a blower-gun system was installed with 40 pellets capability. The experience gained with this system will be used for the specification of a future steady-state pellet injector system. One important motivation for a pellet injector (Dibon 2014 Master-Thesis Technical University Munich, Max-Planck Institut IPP) on W7-X is the mitigation of hollow density profiles expected in case of predominant neoclassical transport. For long-pulse operation of up to 30 min, only electron cyclotron resonance heating is available on W7-X. Hence, pellet injection will be the only source for deep particle fueling. Deep particle fueling by pellets in tokamaks is supported by a grad-B drift, if the pellets are injected from the magnetic high-field-side. This approach was tested in W7-X, as well. The injectionmore » of series of pellets was also tested. Here, deep fueling is supported for later pellets in the series by the plasma cooling following the initial pellets in the same series. As in earlier experiments in the heliotron LHD (Takeiri et al 2017 Nucl. Fusion 57 102023), deep and rapid fueling could be achieved successfully in W7-X.« less

Authors:
ORCiD logo [1];  [1];  [1]; ORCiD logo [2];  [2];  [1]; ORCiD logo [1];  [1];  [1];  [3];  [1];  [4];  [1];  [1];  [1];  [1];  [5];  [1];  [6];  [1] more »;  [4]; ORCiD logo [1];  [1];  [7];  [1]; ORCiD logo [1];  [4];  [1]; ORCiD logo [1]; ORCiD logo [1];  [1];  [1];  [6];  [1];  [1];  [8]; ORCiD logo [9];  [1] « less
  1. Max-Planck Inst. fuer Plasmaphysik IPP, Greifswald (Germany)
  2. CIEMAT, Madrid (Spain)
  3. LPP-ERM/KMS, Brussels (Belgium)
  4. Max-Planck Inst. fuer Plasmaphysik IPP, Garching (Germany)
  5. Atominstitut TU Wien, Vienna (Austria)
  6. Wigner Research Centre for Physiks, Budapest (Hungary)
  7. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  8. Univ. of Wisconsin, Madison, WI (United States)
  9. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
Foreign Funding; USDOE
Contributing Org.:
Wendelstein 7-X Team
OSTI Identifier:
1569618
Report Number(s):
LA-UR-19-23947
Journal ID: ISSN 0741-3335
Grant/Contract Number:  
89233218CNA000001
Resource Type:
Accepted Manuscript
Journal Name:
Plasma Physics and Controlled Fusion
Additional Journal Information:
Journal Volume: 61; Journal Issue: 9; Journal ID: ISSN 0741-3335
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Magnetic Fusion Energy; ice pellet injection; central particle fueling; particle transport in an advanced stellarator

Citation Formats

Baldzuhn, J., Damm, H., Beidler, C. D., McCarthy, K., Panadero, N., Biedermann, C., Bozhenkov, S. A., Brunner, K. J., Fuchert, G., Kazakov, Y., Beurskens, M., Dibon, M., Geiger, J., Grulke, O., Höfel, U., Klinger, T., Köchl, F., Knauer, J., Kocsis, G., Kornejew, P., Lang, P. T., Langenberg, A., Laqua, H., Pablant, N. A., Pasch, E., Pedersen, T. S., Ploeckl, B., Rahbarnia, K., Schlisio, G., Scott, E. R., Stange, T., von Stechow, A., Szepesi, T., Turkin, Y., Wagner, F., Winters, V., Wurden, Glen Anthony, and Zhang, D. Pellet fueling experiments in Wendelstein 7-X. United States: N. p., 2019. Web. doi:10.1088/1361-6587/ab3567.
Baldzuhn, J., Damm, H., Beidler, C. D., McCarthy, K., Panadero, N., Biedermann, C., Bozhenkov, S. A., Brunner, K. J., Fuchert, G., Kazakov, Y., Beurskens, M., Dibon, M., Geiger, J., Grulke, O., Höfel, U., Klinger, T., Köchl, F., Knauer, J., Kocsis, G., Kornejew, P., Lang, P. T., Langenberg, A., Laqua, H., Pablant, N. A., Pasch, E., Pedersen, T. S., Ploeckl, B., Rahbarnia, K., Schlisio, G., Scott, E. R., Stange, T., von Stechow, A., Szepesi, T., Turkin, Y., Wagner, F., Winters, V., Wurden, Glen Anthony, & Zhang, D. Pellet fueling experiments in Wendelstein 7-X. United States. doi:10.1088/1361-6587/ab3567.
Baldzuhn, J., Damm, H., Beidler, C. D., McCarthy, K., Panadero, N., Biedermann, C., Bozhenkov, S. A., Brunner, K. J., Fuchert, G., Kazakov, Y., Beurskens, M., Dibon, M., Geiger, J., Grulke, O., Höfel, U., Klinger, T., Köchl, F., Knauer, J., Kocsis, G., Kornejew, P., Lang, P. T., Langenberg, A., Laqua, H., Pablant, N. A., Pasch, E., Pedersen, T. S., Ploeckl, B., Rahbarnia, K., Schlisio, G., Scott, E. R., Stange, T., von Stechow, A., Szepesi, T., Turkin, Y., Wagner, F., Winters, V., Wurden, Glen Anthony, and Zhang, D. Tue . "Pellet fueling experiments in Wendelstein 7-X". United States. doi:10.1088/1361-6587/ab3567. https://www.osti.gov/servlets/purl/1569618.
@article{osti_1569618,
title = {Pellet fueling experiments in Wendelstein 7-X},
author = {Baldzuhn, J. and Damm, H. and Beidler, C. D. and McCarthy, K. and Panadero, N. and Biedermann, C. and Bozhenkov, S. A. and Brunner, K. J. and Fuchert, G. and Kazakov, Y. and Beurskens, M. and Dibon, M. and Geiger, J. and Grulke, O. and Höfel, U. and Klinger, T. and Köchl, F. and Knauer, J. and Kocsis, G. and Kornejew, P. and Lang, P. T. and Langenberg, A. and Laqua, H. and Pablant, N. A. and Pasch, E. and Pedersen, T. S. and Ploeckl, B. and Rahbarnia, K. and Schlisio, G. and Scott, E. R. and Stange, T. and von Stechow, A. and Szepesi, T. and Turkin, Y. and Wagner, F. and Winters, V. and Wurden, Glen Anthony and Zhang, D.},
abstractNote = {During the two most recent experimental campaigns in the advanced stellarator Wendelstein 7-X (W7-X) (Klinger et al 2017 Plasma Phys. Control. Fusion 59 014018; Bosch et al 2017 Nucl. Fusion 57 116015; Wolf et al 2017 Nucl. Fusion 57 102020; Pedersen et al 2017 Phys. Plasmas 24 0555030) hydrogen ice pellet injection was performed for the first time. In order to investigate the potential of pellet fueling in W7-X and to study the particle deposition in a large stellarator, a blower-gun system was installed with 40 pellets capability. The experience gained with this system will be used for the specification of a future steady-state pellet injector system. One important motivation for a pellet injector (Dibon 2014 Master-Thesis Technical University Munich, Max-Planck Institut IPP) on W7-X is the mitigation of hollow density profiles expected in case of predominant neoclassical transport. For long-pulse operation of up to 30 min, only electron cyclotron resonance heating is available on W7-X. Hence, pellet injection will be the only source for deep particle fueling. Deep particle fueling by pellets in tokamaks is supported by a grad-B drift, if the pellets are injected from the magnetic high-field-side. This approach was tested in W7-X, as well. The injection of series of pellets was also tested. Here, deep fueling is supported for later pellets in the series by the plasma cooling following the initial pellets in the same series. As in earlier experiments in the heliotron LHD (Takeiri et al 2017 Nucl. Fusion 57 102023), deep and rapid fueling could be achieved successfully in W7-X.},
doi = {10.1088/1361-6587/ab3567},
journal = {Plasma Physics and Controlled Fusion},
number = 9,
volume = 61,
place = {United States},
year = {2019},
month = {8}
}

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