1
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Feng X, Calcines A, Sharples RM, Lipschultz B, Perek A, Vijvers WAJ, Harrison JR, Allcock JS, Andrebe Y, Duval BP, Mumgaard RT. Development of an 11-channel multi wavelength imaging diagnostic for divertor plasmas in MAST Upgrade. Rev Sci Instrum 2021; 92:063510. [PMID: 34243542 DOI: 10.1063/5.0043533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 05/19/2021] [Indexed: 06/13/2023]
Abstract
Divertor detachment and alternative divertor magnetic geometries are predicted to be promising approaches to handle the power exhaust of future fusion devices. In order to understand the detachment process caused by volumetric losses in alternative divertor magnetic geometries, a Multi-Wavelength Imaging (MWI) diagnostic has recently been designed and built for the Mega Amp Spherical Tokamak Upgrade. The MWI diagnostic will simultaneously capture 11 spectrally filtered images of the visible light emitted from divertor plasmas and provide crucial knowledge for the interpretation of observations and modeling efforts. This paper presents the optical design, mechanical design, hardware, and test results of an 11-channel MWI system with a field of view of 40°. The optical design shows better than 5 mm FWHM spatial resolution at the plasma on all 11 channels across the whole field of view. The spread of angle of incidence on the surface of each filter is also analyzed to inform the bandwidth specification of the interference filters. The results of the initial laboratory tests demonstrate that a spatial resolution of better than 5 mm FWHM is achieved for all 11 channels, meeting the specifications required for accurate tomography.
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Affiliation(s)
- X Feng
- Centre for Advanced Instrumentation, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - A Calcines
- Centre for Advanced Instrumentation, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - R M Sharples
- Centre for Advanced Instrumentation, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - B Lipschultz
- York Plasma Institute, University of York, York YO10 5DQ, United Kingdom
| | - A Perek
- Dutch Institute for Fundamental Energy Research (DIFFER), De Zaale 20, 5612 AJ Eindhoven, The Netherlands
| | - W A J Vijvers
- Dutch Institute for Fundamental Energy Research (DIFFER), De Zaale 20, 5612 AJ Eindhoven, The Netherlands
| | - J R Harrison
- CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
| | - J S Allcock
- CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
| | - Y Andrebe
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), 1015 Lausanne, Switzerland
| | - B P Duval
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), 1015 Lausanne, Switzerland
| | - R T Mumgaard
- Plasma Science and Fusion Center MIT, Cambridge, Massachusetts 02139, USA
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2
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De Angeli M, Ripamonti D, Ghezzi F, Tolias P, Conti C, Arnas C, Jerab M, Rudakov D, Chrobak C, Irby J, LaBombard B, Lipschultz B, Maddaluno G. Cross machine investigation of magnetic tokamak dust: Morphological and elemental analysis. Fusion Engineering and Design 2021. [DOI: 10.1016/j.fusengdes.2021.112315] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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3
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Carr M, Meakins A, Silburn SA, Karhunen J, Bernert M, Bowman C, Callarelli A, Carvalho P, Giroud C, Harrison JR, Henderson SS, Huber A, Lipschultz B, Lunt T, Moulton D, Reimold F. Physically principled reflection models applied to filtered camera imaging inversions in metal walled fusion machines. Rev Sci Instrum 2019; 90:043504. [PMID: 31043003 DOI: 10.1063/1.5092781] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 03/29/2019] [Indexed: 06/09/2023]
Abstract
Ray-tracing techniques are applied to filtered divertor imaging, a diagnostic that has long suffered from artifacts due to the polluting effect of reflected light in metal walled fusion machines. Physically realistic surface reflections were modeled using a Cook-Torrance micro-facet bi-directional reflection distribution function applied to a high resolution mesh of the vessel geometry. In the absence of gonioreflectometer measurements, a technique was developed to fit the free parameters of the Cook-Torrance model against images of the JET in-vessel light sources. By coupling this model with high fidelity plasma fluid simulations, photo-realistic renderings of a number of tokamak plasma emission scenarios were generated. Finally, a sensitivity matrix describing the optical coupling of a JET divertor camera and the emission profile of the plasma was obtained, including full reflection effects. These matrices are used to perform inversions on measured data and shown to reduce the level of artifacts in inverted emission profiles.
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Affiliation(s)
- M Carr
- UKAEA/CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
| | - A Meakins
- UKAEA/CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
| | - S A Silburn
- UKAEA/CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
| | - J Karhunen
- Department of Applied Physics, Aalto University School of Science, P.O. Box 11100, FI-00076 Aalto, Finland
| | - M Bernert
- Max-Planck-Institut für Plasmaphysik, 85748 Garching, Germany
| | - C Bowman
- Department of Physics, York Plasma Institute, University of York, Heslington, York, United Kingdom
| | - A Callarelli
- UKAEA/CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
| | - P Carvalho
- UKAEA/CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
| | - C Giroud
- UKAEA/CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
| | - J R Harrison
- UKAEA/CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
| | - S S Henderson
- UKAEA/CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
| | - A Huber
- Forschungszentrum Jülich GmbH, Institut für Energie-und Klimaforschung - Plasmaphysik, 52425 Jülich, Germany
| | - B Lipschultz
- Department of Physics, York Plasma Institute, University of York, Heslington, York, United Kingdom
| | - T Lunt
- Max-Planck-Institut für Plasmaphysik, 85748 Garching, Germany
| | - D Moulton
- UKAEA/CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
| | - F Reimold
- Max-Planck-Institut für Plasmaphysik, Greifswald, Germany
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4
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Henderson S, Bernert M, Brezinsek S, Carr M, Cavedon M, Dux R, Gahle D, Harrison J, Kallenbach A, Lipschultz B, Lomanowski B, Meigs A, O’Mullane M, Reimold F, Reinke M, Wiesen S. An assessment of nitrogen concentrations from spectroscopic measurements in the JET and ASDEX upgrade divertor. Nuclear Materials and Energy 2019. [DOI: 10.1016/j.nme.2018.12.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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5
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Carr M, Meakins A, Bernert M, David P, Giroud C, Harrison J, Henderson S, Lipschultz B, Reimold F. Description of complex viewing geometries of fusion tomography diagnostics by ray-tracing. Rev Sci Instrum 2018; 89:083506. [PMID: 30184695 DOI: 10.1063/1.5031087] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 07/24/2018] [Indexed: 06/08/2023]
Abstract
Ray-tracing techniques are applied to bolometry, a diagnostic where the finite collection volume is particularly sensitive to the machine and detector configuration. A technique is presented that can handle arbitrarily complex aperture and collimator geometries, neglecting reflection effects. Sight lines from the ASDEX Upgrade bolometer foils were ray-traced with a path tracing algorithm, where the optical path is represented by a statistical bundle of ray paths connecting the foil surface with the slit geometry. By using the full 3D machine model for the detector box and first wall, effects such as occlusion and vignetting were included in the calculation of the bolometer's étendue. Inversion matrices calculated with the ray-tracing technique were compared with the more conventional single-ray approach and shown to be naturally more constrained, requiring less regularisation. The two models were tested on a sample radiation scenario, and the common single-ray approximation is shown to be insufficient. These results are particularly relevant for the divertor where strong emission gradients may be present. The technique developed generalises well to arbitrarily complex viewing geometries and collimators, opening up a new design space for bolometer configurations that might not normally have been considered.
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Affiliation(s)
- M Carr
- CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
| | - A Meakins
- CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
| | - M Bernert
- Max-Planck-Institut für Plasmaphysik, 85748 Garching, Germany
| | - P David
- Max-Planck-Institut für Plasmaphysik, 85748 Garching, Germany
| | - C Giroud
- CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
| | - J Harrison
- CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
| | - S Henderson
- CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
| | - B Lipschultz
- Department of Physics, York Plasma Institute, University of York, Heslington, York, United Kingdom
| | - F Reimold
- Max-Planck-Institut für Plasmaphysik, Greifswald, Germany
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6
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Reimerdes H, Alberti S, Blanchard P, Bruzzone P, Chavan R, Coda S, Duval B, Fasoli A, Labit B, Lipschultz B, Lunt T, Martin Y, Moret JM, Sheikh U, Sudki B, Testa D, Theiler C, Toussaint M, Uglietti D, Vianello N, Wischmeier M. TCV divertor upgrade for alternative magnetic configurations. Nuclear Materials and Energy 2017. [DOI: 10.1016/j.nme.2017.02.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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7
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Bernert M, Wischmeier M, Huber A, Reimold F, Lipschultz B, Lowry C, Brezinsek S, Dux R, Eich T, Kallenbach A, Lebschy A, Maggi C, McDermott R, Pütterich T, Wiesen S. Power exhaust by SOL and pedestal radiation at ASDEX Upgrade and JET. Nuclear Materials and Energy 2017. [DOI: 10.1016/j.nme.2016.12.029] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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8
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Labit B, Canal G, Christen N, Duval B, Lipschultz B, Lunt T, Nespoli F, Reimerdes H, Sheikh U, Theiler C, Tsui C, Verhaegh K, Vijvers W. Experimental studies of the snowflake divertor in TCV. Nuclear Materials and Energy 2017. [DOI: 10.1016/j.nme.2017.03.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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9
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Terry JL, LaBombard B, Lipschultz B, Greenwald MJ, Rice JE, Zweben SJ. The Scrape-Off Layer in Alcator C-Mod: Transport, Turbulence, and Flows. Fusion Science and Technology 2017. [DOI: 10.13182/fst07-a1426] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- J. L. Terry
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - B. LaBombard
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - B. Lipschultz
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - M. J. Greenwald
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. E. Rice
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - S. J. Zweben
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
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10
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Lipschultz B, LaBombard B, Terry JL, Boswell C, Hutchinson IH. Divertor Physics Research on Alcator C-Mod. Fusion Science and Technology 2017. [DOI: 10.13182/fst07-a1428] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- B. Lipschultz
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - B. LaBombard
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. L. Terry
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - C. Boswell
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - I. H. Hutchinson
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
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11
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Affiliation(s)
- B. Lipschultz
- Massachusetts Institute of Technology Plasma Science and Fusion Center, Cambridge Massachusetts 02139
| | - B. LaBombard
- Massachusetts Institute of Technology Plasma Science and Fusion Center, Cambridge Massachusetts 02139
| | - S. Lisgo
- University of Toronto, Institute for Aerospace Studies, Toronto M3H 5T6, Canada
| | - J. L. Terry
- Plasma Science and Fusion Center, Massachusetts Institute of Technology Cambridge Massachusetts 02139
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12
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Basse NP, Dominguez A, Edlund EM, Fiore CL, Granetz RS, Hubbard AE, Hughes JW, Hutchinson IH, Irby JH, LaBombard B, Lin L, Lin Y, Lipschultz B, Liptac JE, Marmar ES, Mossessian DA, Parker RR, Porkolab M, Rice JE, Snipes JA, Tang V, Terry JL, Wolfe SM, Wukitch SJ, Zhurovich K, Bravenec RV, Phillips PE, Rowan WL, Kramer GJ, Schilling G, Scott SD, Zweben SJ. Diagnostic Systems on Alcator C-Mod. Fusion Science and Technology 2017. [DOI: 10.13182/fst07-a1434] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- N. P. Basse
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - A. Dominguez
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - E. M. Edlund
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - C. L. Fiore
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - R. S. Granetz
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - A. E. Hubbard
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. W. Hughes
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - I. H. Hutchinson
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. H. Irby
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - B. LaBombard
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - L. Lin
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - Y. Lin
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - B. Lipschultz
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. E. Liptac
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - E. S. Marmar
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - D. A. Mossessian
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - R. R. Parker
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - M. Porkolab
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. E. Rice
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. A. Snipes
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - V. Tang
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. L. Terry
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - S. M. Wolfe
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - S. J. Wukitch
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - K. Zhurovich
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - R. V. Bravenec
- Fusion Research Center, University of Texas, Austin, Texas 78712
| | - P. E. Phillips
- Fusion Research Center, University of Texas, Austin, Texas 78712
| | - W. L. Rowan
- Fusion Research Center, University of Texas, Austin, Texas 78712
| | - G. J. Kramer
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
| | - G. Schilling
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
| | - S. D. Scott
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
| | - S. J. Zweben
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
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13
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Greenwald M, Basse N, Bonoli P, Bravenec R, Edlund E, Ernst D, Fiore C, Granetz R, Hubbard A, Hughes J, Hutchinson I, Irby J, LaBombard B, Lin L, Lin Y, Lipschultz B, Marmar E, Mikkelsen D, Mossessian D, Phillips P, Porkolab M, Rice J, Rowan W, Scott S, Snipes J, Terry J, Wolfe S, Wukitch S, Zhurovich K. Confinement and Transport Research in Alcator C-Mod. Fusion Science and Technology 2017. [DOI: 10.13182/fst07-a1422] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- M. Greenwald
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - N. Basse
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - P. Bonoli
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | | | - E. Edlund
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - D. Ernst
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - C. Fiore
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - R. Granetz
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - A. Hubbard
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - J. Hughes
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - I. Hutchinson
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - J. Irby
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - B. LaBombard
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - L. Lin
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - Y. Lin
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - B. Lipschultz
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - E. Marmar
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - D. Mikkelsen
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - D. Mossessian
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | | | - M. Porkolab
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - J. Rice
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - W. Rowan
- University of Texas, Austin, Texas
| | - S. Scott
- Princeton Plasma Physics Laboratory, Princeton, New Jersey
| | - J. Snipes
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - J. Terry
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - S. Wolfe
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - S. Wukitch
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
| | - K. Zhurovich
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02138
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14
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Bonoli PT, Parker R, Wukitch SJ, Lin Y, Porkolab M, Wright JC, Edlund E, Graves T, Lin L, Liptac J, Parisot A, Schmidt AE, Tang V, Beck W, Childs R, Grimes M, Gwinn D, Johnson D, Irby J, Kanojia A, Koert P, Marazita S, Marmar E, Terry D, Vieira R, Wallace G, Zaks J, Bernabei S, Brunkhorse C, Ellis R, Fredd E, Greenough N, Hosea J, Kung CC, Loesser GD, Rushinski J, Schilling G, Phillips CK, Wilson JR, Harvey RW, Fiore CL, Granetz R, Greenwald M, Hubbard AE, Hutchinson IH, Labombard B, Lipschultz B, Rice J, Snipes JA, Terry J, Wolfe SM. Wave-Particle Studies in the Ion Cyclotron and Lower Hybrid Ranges of Frequencies in Alcator C-Mod. Fusion Science and Technology 2017. [DOI: 10.13182/fst07-a1430] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- P. T. Bonoli
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - R. Parker
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - S. J. Wukitch
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - Y. Lin
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - M. Porkolab
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. C. Wright
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - E. Edlund
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - T. Graves
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - L. Lin
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. Liptac
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - A. Parisot
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - A. E. Schmidt
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - V. Tang
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - W. Beck
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - R. Childs
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - M. Grimes
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - D. Gwinn
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - D. Johnson
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. Irby
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - A. Kanojia
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - P. Koert
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - S. Marazita
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - E. Marmar
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - D. Terry
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - R. Vieira
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - G. Wallace
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. Zaks
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - S. Bernabei
- Princeton University, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
| | - C. Brunkhorse
- Princeton University, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
| | - R. Ellis
- Princeton University, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
| | - E. Fredd
- Princeton University, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
| | - N. Greenough
- Princeton University, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
| | - J. Hosea
- Princeton University, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
| | - C. C. Kung
- Princeton University, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
| | - G. D. Loesser
- Princeton University, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
| | - J. Rushinski
- Princeton University, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
| | - G. Schilling
- Princeton University, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
| | - C. K. Phillips
- Princeton University, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
| | - J. R. Wilson
- Princeton University, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
| | | | - C. L. Fiore
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - R. Granetz
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - M. Greenwald
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - A. E. Hubbard
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - I. H. Hutchinson
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - B. Labombard
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - B. Lipschultz
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. Rice
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. A. Snipes
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. Terry
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - S. M. Wolfe
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
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15
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Brunner D, Burke W, Kuang AQ, LaBombard B, Lipschultz B, Wolfe S. Feedback system for divertor impurity seeding based on real-time measurements of surface heat flux in the Alcator C-Mod tokamak. Rev Sci Instrum 2016; 87:023504. [PMID: 26931846 DOI: 10.1063/1.4941047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Accepted: 01/16/2016] [Indexed: 06/05/2023]
Abstract
Mitigation of the intense heat flux to the divertor is one of the outstanding problems in fusion energy. One technique that has shown promise is impurity seeding, i.e., the injection of low-Z gaseous impurities (typically N2 or Ne) to radiate and dissipate the power before it arrives to the divertor target plate. To this end, the Alcator C-Mod team has created a first-of-its-kind feedback system to control the injection of seed gas based on real-time surface heat flux measurements. Surface thermocouples provide real-time measurements of the surface temperature response to the plasma heat flux. The surface temperature measurements are inputted into an analog computer that "solves" the 1-D heat transport equation to deliver accurate, real-time signals of the surface heat flux. The surface heat flux signals are sent to the C-Mod digital plasma control system, which uses a proportional-integral-derivative (PID) algorithm to control the duty cycle demand to a pulse width modulated piezo valve, which in turn controls the injection of gas into the private flux region of the C-Mod divertor. This paper presents the design and implementation of this new feedback system as well as initial results using it to control divertor heat flux.
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Affiliation(s)
- D Brunner
- 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
| | - 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
| | - B Lipschultz
- Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - S Wolfe
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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16
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Churchill RM, Theiler C, Lipschultz B, Dux R, Pütterich T, Viezzer E. Development of the gas puff charge exchange recombination spectroscopy (GP-CXRS) technique for ion measurements in the plasma edge. Rev Sci Instrum 2013; 84:093505. [PMID: 24094058 DOI: 10.1063/1.4821084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A novel charge-exchange recombination spectroscopy (CXRS) diagnostic method is presented, which uses a simple thermal gas puff for its donor neutral source, instead of the typical high-energy neutral beam. This diagnostic, named gas puff CXRS (GP-CXRS), is used to measure ion density, velocity, and temperature in the tokamak edge/pedestal region with excellent signal-background ratios, and has a number of advantages to conventional beam-based CXRS systems. Here we develop the physics basis for GP-CXRS, including the neutral transport, the charge-exchange process at low energies, and effects of energy-dependent rate coefficients on the measurements. The GP-CXRS hardware setup is described on two separate tokamaks, Alcator C-Mod and ASDEX Upgrade. Measured spectra and profiles are also presented. Profile comparisons of GP-CXRS and a beam based CXRS system show good agreement. Emphasis is given throughout to describing guiding principles for users interested in applying the GP-CXRS diagnostic technique.
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Affiliation(s)
- R M Churchill
- MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA
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17
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Ochoukov R, Whyte DG, Lipschultz B, Labombard B, Wukitch S. Interpretation and implementation of an ion sensitive probe as a plasma potential diagnostic. Rev Sci Instrum 2010; 81:10E111. [PMID: 21033976 DOI: 10.1063/1.3483192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
An ion sensitive probe (ISP) is developed as a robust diagnostic for measuring plasma potentials (Φ(P)) in magnetized plasmas. The ISP relies on the large difference between the ion and electron gyroradii (ρ(i)/ρ(e)∼60) to reduce the electron collection at a collector recessed behind a separately biased wall distance ∼ρ(i). We develop a new ISP method to measure the plasma potential that is independent of the precise position and shape of the collector. Φ(P) is found as the wall potential when charged current to the probe collector vanishes during the voltage sweep. The plasma potentials obtained from the ISP match Φ(P) measured with an emissive probe over a wide range of plasma conditions in a small magnetized plasma.
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Affiliation(s)
- R Ochoukov
- PSFC, MIT, 77 Mass. Avenue, Cambridge, Massachusetts 02139, USA.
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