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Sabot R, Hennequin P, Colas L. Fluctuation Measurements and Their Link with Transport on Tore Supra. FUSION SCIENCE AND TECHNOLOGY 2017. [DOI: 10.13182/fst09-a9176] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- R. Sabot
- CEA, IRFM, F-13108 Saint-Paul-lez-Durance, France
| | - P. Hennequin
- Laboratoire de Physique des Plasmas, CNRS, Ecole Polytechnique, 91128 Palaiseau, France
| | - L. Colas
- CEA, IRFM, F-13108 Saint-Paul-lez-Durance, France
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Thomas DM, McKee GR, Burrell KH, Levinton F, Foley EL, Fisher RK. Chapter 6: Active Spectroscopy. FUSION SCIENCE AND TECHNOLOGY 2017. [DOI: 10.13182/fst08-a1678] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- D. M. Thomas
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | - G. R. McKee
- University of Wisconsin-Madison, Madison, Wisconsin
| | - K. H. Burrell
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
| | | | | | - R. K. Fisher
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608
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A tangential CO 2 laser collective scattering system for measuring short-scale turbulent fluctuations in the EAST superconducting tokamak. FUSION ENGINEERING AND DESIGN 2014. [DOI: 10.1016/j.fusengdes.2014.09.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Ghim YC, Schekochihin AA, Field AR, Abel IG, Barnes M, Colyer G, Cowley SC, Parra FI, Dunai D, Zoletnik S. Experimental signatures of critically balanced turbulence in MAST. PHYSICAL REVIEW LETTERS 2013; 110:145002. [PMID: 25166998 DOI: 10.1103/physrevlett.110.145002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Indexed: 06/03/2023]
Abstract
Beam emission spectroscopy (BES) measurements of ion-scale density fluctuations in the MAST tokamak are used to show that the turbulence correlation time, the drift time associated with ion temperature or density gradients, the particle (ion) streaming time along the magnetic field, and the magnetic drift time are consistently comparable, suggesting a "critically balanced" turbulence determined by the local equilibrium. The resulting scalings of the poloidal and radial correlation lengths are derived and tested. The nonlinear time inferred from the density fluctuations is longer than the other times; its ratio to the correlation time scales as ν(*i)(-0.8 ± 0.1), where ν(*i) = ion collision rate/streaming rate. This is consistent with turbulent decorrelation being controlled by a zonal component, invisible to the BES, with an amplitude exceeding those of the drift waves by ∼ ν(*i)(-0.8).
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Affiliation(s)
- Y-C Ghim
- Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP, United Kingdom and EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB, United Kingdom and Department of Nuclear and Quantum Engineering, KAIST, Daejeon 305-701, Republic of Korea
| | - A A Schekochihin
- Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP, United Kingdom and Merton College, Oxford OX1 4JD, United Kingdom
| | - A R Field
- EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB, United Kingdom
| | - I G Abel
- Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP, United Kingdom and Merton College, Oxford OX1 4JD, United Kingdom
| | - M Barnes
- Plasma Science and Fusion Center, MIT, Cambridge, Massachusetts 02139, USA and Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee 37831, USA
| | - G Colyer
- Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP, United Kingdom and EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB, United Kingdom
| | - S C Cowley
- EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB, United Kingdom and Blackett Laboratory, Imperial College, London SW7 2AZ, United Kingdom
| | - F I Parra
- Plasma Science and Fusion Center, MIT, Cambridge, Massachusetts 02139, USA
| | - D Dunai
- Wigner Research Centre for Physics, Association EURATOM/HAS, P.O. Box 49, H-1525 Budapest, Hungary
| | - S Zoletnik
- Wigner Research Centre for Physics, Association EURATOM/HAS, P.O. Box 49, H-1525 Budapest, Hungary
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Gürcan OD, Garbet X, Hennequin P, Diamond PH, Casati A, Falchetto GL. Wave-number spectrum of drift-wave turbulence. PHYSICAL REVIEW LETTERS 2009; 102:255002. [PMID: 19659085 DOI: 10.1103/physrevlett.102.255002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Indexed: 05/28/2023]
Abstract
A simple model for the evolution of turbulence fluctuation spectra, which includes neighboring interactions leading to the usual dual cascade as well as disparate scale interactions corresponding to refraction by large scale structures, is derived. The model recovers the usual Kraichnan-Kolmogorov picture in the case of exclusively local interactions and midrange drive. On the other hand, when disparate scale interactions are dominant, a simple spectrum for the density fluctuations of the form |nk|2 proportional to k(-3)/(1+k2)2 is obtained. This simple prediction is then compared to, and found to be in fair agreement with, Tore Supra CO2 laser scattering data.
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Affiliation(s)
- O D Gürcan
- Laboratoire de Physique des Plasmas, Ecole Polytechnique, CNRS, 91128 Palaiseau Cedex, France.
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Jakubowski M, Fonck RJ, McKee GR. Observation of coherent sheared turbulence flows in the DIII-D Tokamak. PHYSICAL REVIEW LETTERS 2002; 89:265003. [PMID: 12484829 DOI: 10.1103/physrevlett.89.265003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2001] [Indexed: 05/24/2023]
Abstract
Time-resolved measurements of the turbulent density flow field in a tokamak plasma reveal low-frequency ( approximately 15 KHz), coherent oscillations in the poloidal flow, v(theta). These flow oscillations have a long poloidal wavelength (m<3) and narrow radial extent (k(r)rho(i) approximately 0.2). The estimated flow-shearing rate is of the same order of magnitude as the turbulence decorrelation rate and may thus regulate the turbulence amplitude. These features are consistent with theoretically predicted axisymmetric, self-regulating, sheared flows recognized as geodesic acoustic modes.
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Affiliation(s)
- M Jakubowski
- University of Wisconsin-Madison, 1500 Engineering Drive, Madison, Wisconsin 53706-1687, USA
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Coda S, Porkolab M, Burrell KH. Signature of turbulent zonal flows observed in the DIII-D tokamak. PHYSICAL REVIEW LETTERS 2001; 86:4835-4838. [PMID: 11384360 DOI: 10.1103/physrevlett.86.4835] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2000] [Indexed: 05/23/2023]
Abstract
The spectrum of turbulent density fluctuations at long poloidal wavelengths in the edge plasma of the DIII-D tokamak peaks at nonzero radial wave number. The associated electric-potential fluctuations cause sheared E x B flows primarily in the poloidal direction. These zonal flows have been predicted by theory and are believed to regulate the overall level of turbulence and anomalous transport. This study provides the first indirect experimental identification of zonal flows.
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Affiliation(s)
- S Coda
- Department of Physics and Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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McKee G, Burrell K, Fonck R, Jackson G, Murakami M, Staebler G, Thomas D, West P. Impurity-induced suppression of core turbulence and transport in the DIII-D tokamak. PHYSICAL REVIEW LETTERS 2000; 84:1922-1925. [PMID: 11017661 DOI: 10.1103/physrevlett.84.1922] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/1999] [Indexed: 05/23/2023]
Abstract
Turbulence is significantly reduced in a tokamak plasma as a result of neon seeding of an L-mode discharge. Correspondingly, confinement is improved and cross-field ion thermal transport reduced. Fully saturated turbulence in the range 0.1</=k( perpendicular)rho(s)</=0. 6 is measured at rho = 0.7 and exhibits a factor of 5 reduction in total power after neon injection, with almost complete suppression for k( perpendicular)rho(s)>0.35. These observations are consistent with a reduction in the calculated linear growth rate for k( perpendicular)rho(s)>0.5 and an increase in the measured ExB flow shearing rate.
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Affiliation(s)
- G McKee
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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Hamada Y. Density, potential and magnetic turbulence measurements by a heavy ion beam probe in tokamak plasmas. FUSION ENGINEERING AND DESIGN 1997. [DOI: 10.1016/s0920-3796(96)00674-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Hamada Y, Nishizawa A, Kawasumi Y, Fujisawa A, Iguchi H. Transition of fluctuation characteristics observed by a heavy ion beam probe in the JIPP T-IIU tokamak. FUSION ENGINEERING AND DESIGN 1997. [DOI: 10.1016/s0920-3796(96)00579-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Mazzucato E, Batha SH, Beer M, Bell M, Bell RE, Budny RV, Bush C, Hahm TS, Hammett GW, Levinton FM, Nazikian R, Park H, Rewoldt G, Schmidt GL, Synakowski EJ, Tang WM, Taylor G, Zarnstorff MC. Turbulent Fluctuations in TFTR Configurations with Reversed Magnetic Shear. PHYSICAL REVIEW LETTERS 1996; 77:3145-3148. [PMID: 10062145 DOI: 10.1103/physrevlett.77.3145] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Carati D, Chriaa K, Balescu R. Renormalization-group theory of plasma microturbulence. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1994; 50:1444-1457. [PMID: 9962113 DOI: 10.1103/physreve.50.1444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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14
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Durst RD, Fonck RJ, Kim JS, Paul SF, Bretz N, Bush C, Chang Z, Hulse R. Observation of a localized transition from edge to core density turbulence in the TFTR tokamak. PHYSICAL REVIEW LETTERS 1993; 71:3135-3138. [PMID: 10054866 DOI: 10.1103/physrevlett.71.3135] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Parker SE, Lee WW, Santoro RA. Gyrokinetic simulation of ion temperature gradient driven turbulence in 3D toroidal geometry. PHYSICAL REVIEW LETTERS 1993; 71:2042-2045. [PMID: 10054568 DOI: 10.1103/physrevlett.71.2042] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Mazzucato E, Nazikian R. Radial scale length of turbulent fluctuations in the main core of TFTR plasmas. PHYSICAL REVIEW LETTERS 1993; 71:1840-1843. [PMID: 10054513 DOI: 10.1103/physrevlett.71.1840] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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