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Gonzalez-Martin J, Garcia-Munoz M, Sieglin B, Herrmann A, Lunt T, Ayllon-Guerola J, Galdon-Quiroga J, Hidalgo-Salaverri J, Kovacsik A, Rivero-Rodriguez JF, Sanchis L, Silvagni D, Zoletnik S, Dominguez J. Self-adaptive diagnostic of radial fast-ion loss measurements on the ASDEX Upgrade tokamak (invited). THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:053538. [PMID: 34243326 DOI: 10.1063/5.0043756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 04/28/2021] [Indexed: 06/13/2023]
Abstract
A poloidal array of scintillator-based Fast-Ion Loss Detectors (FILDs) has been installed in the ASDEX Upgrade (AUG) tokamak. While all AUG FILD systems are mounted on reciprocating arms driven externally by servomotors, the reciprocating system of the FILD probe located just below the midplane is based on a magnetic coil that is energized in real-time by the AUG discharge control system. This novel reciprocating system allows, for the first time, real-time control of the FILD position including infrared measurements of its probe head temperature to avoid overheating. This considerably expands the diagnostic operational window, enabling unprecedented radial measurements of fast-ion losses. Fast collimator-slit sweeping (up to 0.2 mm/ms) is used to obtain radially resolved velocity-space measurements along 8 cm within the scrape-off layer. This provides a direct evaluation of the neutral beam deposition profiles via first-orbit losses. Moreover, the light-ion beam probe (LIBP) technique is used to infer radial profiles of fast-ion orbit deflection. This radial-LIBP technique is applied to trapped orbits (exploring both the plasma core and the FILD stroke near the wall), enabling radial localization of internal plasma fluctuations (neoclassical tearing modes). This is quantitatively compared against electron cyclotron emission measurements, showing excellent agreement. For the first time, radial profiles of fast-ion losses in MHD quiescent plasmas as well as in the presence of magnetic islands and edge localized modes are presented.
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Affiliation(s)
- J Gonzalez-Martin
- Department of Mechanical Engineering and Manufacturing, Universidad de Sevilla, 41092 Sevilla, Spain
| | - M Garcia-Munoz
- Centro Nacional de Aceleradores (CNA), 41092 Sevilla, Spain
| | - B Sieglin
- Max Planck Institute for Plasma Physics, 85748 Garching, Germany
| | - A Herrmann
- Max Planck Institute for Plasma Physics, 85748 Garching, Germany
| | - T Lunt
- Max Planck Institute for Plasma Physics, 85748 Garching, Germany
| | - J Ayllon-Guerola
- Department of Mechanical Engineering and Manufacturing, Universidad de Sevilla, 41092 Sevilla, Spain
| | - J Galdon-Quiroga
- Department of Atomic, Molecular and Nuclear Physics, Universidad de Sevilla, 41012 Sevilla, Spain
| | - J Hidalgo-Salaverri
- Department of Mechanical Engineering and Manufacturing, Universidad de Sevilla, 41092 Sevilla, Spain
| | - A Kovacsik
- Budapest University of Technology and Economics, 1111 Budapest, Hungary
| | - J F Rivero-Rodriguez
- Department of Mechanical Engineering and Manufacturing, Universidad de Sevilla, 41092 Sevilla, Spain
| | - L Sanchis
- Department of Applied Physics, Aalto University, FI-00076 Aalto, Finland
| | - D Silvagni
- Max Planck Institute for Plasma Physics, 85748 Garching, Germany
| | | | - J Dominguez
- Department of Mechanical Engineering and Manufacturing, Universidad de Sevilla, 41092 Sevilla, Spain
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Brunner D, Kuang AQ, LaBombard B, Burke W. Linear servomotor probe drive system with real-time self-adaptive position control for the Alcator C-Mod tokamak. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:073501. [PMID: 28764551 DOI: 10.1063/1.4990043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A new servomotor drive system has been developed for the horizontal reciprocating probe on the Alcator C-Mod tokamak. Real-time measurements of plasma temperature and density-through use of a mirror Langmuir probe bias system-combined with a commercial linear servomotor and controller enable self-adaptive position control. Probe surface temperature and its rate of change are computed in real time and used to control probe insertion depth. It is found that a universal trigger threshold can be defined in terms of these two parameters; if the probe is triggered to retract when crossing the trigger threshold, it will reach the same ultimate surface temperature, independent of velocity, acceleration, or scrape-off layer heat flux scale length. In addition to controlling the probe motion, the controller is used to monitor and control all aspects of the integrated probe drive system.
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Affiliation(s)
- D Brunner
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Q Kuang
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - B LaBombard
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - W Burke
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Ayllon-Guerola J, Gonzalez-Martin J, Garcia-Munoz M, Rivero-Rodriguez J, Herrmann A, Vorbrugg S, Leitenstern P, Zoletnik S, Galdon J, Garcia Lopez J, Rodriguez-Ramos M, Sanchis-Sanchez L, Dominguez AD, Kocan M, Gunn JP, Garcia-Vallejo D, Dominguez J. A fast feedback controlled magnetic drive for the ASDEX Upgrade fast-ion loss detectors. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:11E705. [PMID: 27910655 DOI: 10.1063/1.4959913] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A magnetically driven fast-ion loss detector system for the ASDEX Upgrade tokamak has been designed and will be presented here. The device is feedback controlled to adapt the detector head position to the heat load and physics requirements. Dynamic simulations have been performed taking into account effects such as friction, coil self-induction, and eddy currents. A real time positioning control algorithm to maximize the detector operational window has been developed. This algorithm considers dynamical behavior and mechanical resistance as well as measured and predicted thermal loads. The mechanical design and real time predictive algorithm presented here may be used for other reciprocating systems.
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Affiliation(s)
- J Ayllon-Guerola
- Department of Atomic, Molecular and Nuclear Physics, Faculty of Physics, University of Seville, 41012 Seville, Spain
| | - J Gonzalez-Martin
- Department of Atomic, Molecular and Nuclear Physics, Faculty of Physics, University of Seville, 41012 Seville, Spain
| | - M Garcia-Munoz
- Department of Atomic, Molecular and Nuclear Physics, Faculty of Physics, University of Seville, 41012 Seville, Spain
| | - J Rivero-Rodriguez
- Department of Atomic, Molecular and Nuclear Physics, Faculty of Physics, University of Seville, 41012 Seville, Spain
| | - A Herrmann
- Max-Planck-Institut für Plasmaphysik, Garching, Germany
| | - S Vorbrugg
- Max-Planck-Institut für Plasmaphysik, Garching, Germany
| | - P Leitenstern
- Max-Planck-Institut für Plasmaphysik, Garching, Germany
| | | | - J Galdon
- Department of Atomic, Molecular and Nuclear Physics, Faculty of Physics, University of Seville, 41012 Seville, Spain
| | - J Garcia Lopez
- Department of Atomic, Molecular and Nuclear Physics, Faculty of Physics, University of Seville, 41012 Seville, Spain
| | - M Rodriguez-Ramos
- Department of Atomic, Molecular and Nuclear Physics, Faculty of Physics, University of Seville, 41012 Seville, Spain
| | - L Sanchis-Sanchez
- Department of Atomic, Molecular and Nuclear Physics, Faculty of Physics, University of Seville, 41012 Seville, Spain
| | - A D Dominguez
- Department of Atomic, Molecular and Nuclear Physics, Faculty of Physics, University of Seville, 41012 Seville, Spain
| | - M Kocan
- ITER Organization, Route de Vinon sur Verdon, 13115 St Paul Lez Durance, France
| | - J P Gunn
- CEA, IRFM, F-13108 Saint Paul Lez Durance, France
| | | | - J Dominguez
- ETSI, University of Seville, 41092 Seville, Spain
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Tsui CK, Taussig DA, Watkins MG, Boivin RL, Stangeby PC. Swinging reciprocating Mach probes for the high field side scrape-off layer in DIII-D. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:10D723. [PMID: 23126897 DOI: 10.1063/1.4733571] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A new pair of in situ reciprocating Mach probes termed swing probes has been deployed on the DIII-D centerpost for the 2012 experimental campaign. When not deployed, the entire assembly is housed in a <5 cm space underneath the centerpost tiles. This design is unique in that the probe swings vertically through the edge plasma, taking measurements along a 180° arc with a 20 cm radius. The motion is powered by actuator coils that interact with the tokamak's magnetic field. Two electrodes maintain a Mach-pair orientation throughout the swing and provide measurements of saturation current, electron temperature, and parallel flow speeds up to the separatrix.
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Affiliation(s)
- C K Tsui
- University of Toronto Institute for Aerospace Studies, Canada.
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Gunn JP, Pascal JY. A magnetically driven reciprocating probe for tokamak scrape-off layer measurements. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2011; 82:123505. [PMID: 22225216 DOI: 10.1063/1.3661128] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A new in situ reciprocating probe system has been developed to provide scrape-off layer measurements in the Tore Supra tokamak. The probe motion is provided by the rotation of an energized coil in the tokamak magnetic field. Simple analytic approximations to the exact numerical model were used to identify the important parameters that govern the dynamics of the system, and optimize the coil geometry, the electrical circuit, and the stiffness of the retaining spring. The linear speed of the probe is directly proportional to the current induced by the coil's rotation; its integral gives the coil position, providing a means to implement real-time feedback control of the probe motion. Two probes were recently mounted on a movable outboard antenna protection limiter in Tore Supra and provided automatic measurements during the 2011 experimental campaign.
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Affiliation(s)
- J P Gunn
- CEA, IRFM, F-13108 Saint-Paul-Lez-Durance, France
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