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Korsholm SB, Chambon A, Gonçalves B, Infante V, Jensen T, Jessen M, Klinkby EB, Larsen AW, Luis R, Nietiadi Y, Nonbøl E, Rasmussen J, Rechena D, Salewski M, Taormina A, Vale A, Varela P, Sanchez L, Ballester RM, Udintsev V, Liu Y. ITER collective Thomson scattering-Preparing to diagnose fusion-born alpha particles (invited). THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:103539. [PMID: 36319374 DOI: 10.1063/5.0101867] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 09/19/2022] [Indexed: 06/16/2023]
Abstract
The ITER Collective Thomson scattering (CTS) diagnostic will measure the dynamics of fusion-born alpha particles in the burning ITER plasma by scattering a 1 MW 60 GHz gyrotron beam off fast-ion induced fluctuations in the plasma. The diagnostic will have seven measurement volumes across the ITER cross section and will resolve the alpha particle energies in the range from 300 keV to 3.5 MeV; importantly, the CTS diagnostic is the only diagnostic capable of measuring confined alpha particles for energies below ∼1.7 MeV and will also be sensitive to the other fast-ion populations. The temporal resolution is 100 ms, allowing the capture of dynamics on that timescale, and the typical spatial resolution is 10-50 cm. The development and design of the in-vessel and primary parts of the CTS diagnostic has been completed. This marks the beginning of a new phase of preparation to maximize the scientific benefit of the diagnostic, e.g., by investigating the capability to contribute to the determination of the fuel-ion ratio and the bulk ion temperature as well as integrating data analysis with other fast-ion and bulk-ion diagnostics.
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Affiliation(s)
- S B Korsholm
- Department of Physics, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - A Chambon
- Department of Physics, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - B Gonçalves
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Univ. Lisboa, 1049001 Lisbon, Portugal
| | - V Infante
- IDMEC, Instituto Superior Técnico, Univ. Lisboa, 1049001 Lisbon, Portugal
| | - T Jensen
- Department of Physics, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - M Jessen
- Department of Physics, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - E B Klinkby
- Department of Physics, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - A W Larsen
- Department of Physics, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - R Luis
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Univ. Lisboa, 1049001 Lisbon, Portugal
| | - Y Nietiadi
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Univ. Lisboa, 1049001 Lisbon, Portugal
| | - E Nonbøl
- Department of Physics, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - J Rasmussen
- Department of Physics, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - D Rechena
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Univ. Lisboa, 1049001 Lisbon, Portugal
| | - M Salewski
- Department of Physics, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - A Taormina
- Department of Physics, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - A Vale
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Univ. Lisboa, 1049001 Lisbon, Portugal
| | - P Varela
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Univ. Lisboa, 1049001 Lisbon, Portugal
| | - L Sanchez
- Fusion for Energy, 08019 Barcelona, Spain
| | | | - V Udintsev
- ITER Organization, 13115 Saint Paul Lez Durance, France
| | - Y Liu
- ITER Organization, 13115 Saint Paul Lez Durance, France
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Abramovic I, Pavone A, Moseev D, Lopes Cardozo NJ, Salewski M, Laqua HP, Stejner M, Stange T, Marsen S, Nielsen SK, Jensen T, Kasparek W. Forward modeling of collective Thomson scattering for Wendelstein 7-X plasmas: Electrostatic approximation. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:023501. [PMID: 30831775 DOI: 10.1063/1.5048361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 01/17/2019] [Indexed: 06/09/2023]
Abstract
In this paper, we present a method for numerical computation of collective Thomson scattering (CTS). We developed a forward model, eCTS, in the electrostatic approximation and benchmarked it against a full electromagnetic model. Differences between the electrostatic and the electromagnetic models are discussed. The sensitivity of the results to the ion temperature and the plasma composition is demonstrated. We integrated the model into the Bayesian data analysis framework Minerva and used it for the analysis of noisy synthetic data sets produced by a full electromagnetic model. It is shown that eCTS can be used for the inference of the bulk ion temperature. The model has been used to infer the bulk ion temperature from the first CTS measurements on Wendelstein 7-X.
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Affiliation(s)
- I Abramovic
- University of Technology Eindhoven, Eindhoven, The Netherlands
| | - A Pavone
- Max-Planck Institut fur Plasma Physik, Greifswald, Germany
| | - D Moseev
- Max-Planck Institut fur Plasma Physik, Greifswald, Germany
| | | | - M Salewski
- Technical University of Denmark, Kongens Lyngby, Denmark
| | - H P Laqua
- Max-Planck Institut fur Plasma Physik, Greifswald, Germany
| | - M Stejner
- Technical University of Denmark, Kongens Lyngby, Denmark
| | - T Stange
- Max-Planck Institut fur Plasma Physik, Greifswald, Germany
| | - S Marsen
- Max-Planck Institut fur Plasma Physik, Greifswald, Germany
| | - S K Nielsen
- Technical University of Denmark, Kongens Lyngby, Denmark
| | - T Jensen
- Technical University of Denmark, Kongens Lyngby, Denmark
| | - W Kasparek
- University of Stuttgart, Stuttgart, Germany
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Stejner M, Nielsen S, Jacobsen AS, Korsholm SB, Leipold F, Meo F, Michelsen PK, Moseev D, Rasmussen J, Salewski M, Schubert M, Stober J, Wagner DH. Resolving the bulk ion region of millimeter-wave collective Thomson scattering spectra at ASDEX Upgrade. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:093504. [PMID: 25273723 DOI: 10.1063/1.4894199] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Collective Thomson scattering (CTS) measurements provide information about the composition and velocity distribution of confined ion populations in fusion plasmas. The bulk ion part of the CTS spectrum is dominated by scattering off fluctuations driven by the motion of thermalized ion populations. It thus contains information about the ion temperature, rotation velocity, and plasma composition. To resolve the bulk ion region and access this information, we installed a fast acquisition system capable of sampling rates up to 12.5 GS/s in the CTS system at ASDEX Upgrade. CTS spectra with frequency resolution in the range of 1 MHz are then obtained through direct digitization and Fourier analysis of the CTS signal. We here describe the design, calibration, and operation of the fast receiver system and give examples of measured bulk ion CTS spectra showing the effects of changing ion temperature, rotation velocity, and plasma composition.
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Affiliation(s)
- M Stejner
- Department of Physics, Association EURATOM-DTU, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - S Nielsen
- Department of Physics, Association EURATOM-DTU, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - A S Jacobsen
- Department of Physics, Association EURATOM-DTU, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - S B Korsholm
- Department of Physics, Association EURATOM-DTU, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - F Leipold
- Department of Physics, Association EURATOM-DTU, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - F Meo
- Department of Physics, Association EURATOM-DTU, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - P K Michelsen
- Department of Physics, Association EURATOM-DTU, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - D Moseev
- Max-Planck-Institut für Plasmaphysik, EURATOM-Association, Boltzmannstr. 2, 85748 Garching, Germany
| | - J Rasmussen
- Department of Physics, Association EURATOM-DTU, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - M Salewski
- Department of Physics, Association EURATOM-DTU, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - M Schubert
- Max-Planck-Institut für Plasmaphysik, EURATOM-Association, Boltzmannstr. 2, 85748 Garching, Germany
| | - J Stober
- Max-Planck-Institut für Plasmaphysik, EURATOM-Association, Boltzmannstr. 2, 85748 Garching, Germany
| | - D H Wagner
- Max-Planck-Institut für Plasmaphysik, EURATOM-Association, Boltzmannstr. 2, 85748 Garching, Germany
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