1
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van Kampen R, de Vries J, Weiland S, de Baar M, van Berkel M. Fast simultaneous estimation of nD transport coefficients and source function in perturbation experiments. Sci Rep 2023; 13:3241. [PMID: 36828895 PMCID: PMC9958020 DOI: 10.1038/s41598-023-30337-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 02/21/2023] [Indexed: 02/26/2023] Open
Abstract
In the calculation of transport coefficients from experimental data precise knowledge of the source is usually assumed, while the identification of the coefficients focuses on specific geometries and one spatial variable. This paper presents a method for the simultaneous estimation of both the distributions of transport coefficients as well as the source profile. A convex solution of the inverse problem is retained which makes the calculations highly computational efficient. Moreover, this allows for the estimation of multi-dimensional transport coefficients, source terms, and in the future the analysis of the effect of regularization on experimental data and transport coefficient distributions.
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Affiliation(s)
- Ricky van Kampen
- DIFFER - Dutch Institute for Fundamental Energy Research, 5612 AJ, Eindhoven, The Netherlands. .,Department of Mechanical Engineering, Eindhoven University of Technology, 5600 MB, Eindhoven, The Netherlands.
| | - Jelle de Vries
- grid.434188.20000 0000 8700 504XDIFFER - Dutch Institute for Fundamental Energy Research, 5612 AJ Eindhoven, The Netherlands ,grid.6852.90000 0004 0398 8763Department of Mechanical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands ,grid.6852.90000 0004 0398 8763Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Siep Weiland
- grid.6852.90000 0004 0398 8763Department of Electrical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Marco de Baar
- grid.434188.20000 0000 8700 504XDIFFER - Dutch Institute for Fundamental Energy Research, 5612 AJ Eindhoven, The Netherlands ,grid.6852.90000 0004 0398 8763Department of Mechanical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Matthijs van Berkel
- DIFFER - Dutch Institute for Fundamental Energy Research, 5612 AJ, Eindhoven, The Netherlands.
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2
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Jin S, Reiman AH, Fisch NJ. Coupled heat pulse propagation in two-fluid plasmas. Phys Rev E 2021; 103:053201. [PMID: 34134323 DOI: 10.1103/physreve.103.053201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 04/16/2021] [Indexed: 11/07/2022]
Abstract
Because of the large mass differences between electrons and ions, the heat diffusion in electron-ion plasmas exhibits more complex behavior than simple heat diffusion found in typical gas mixtures. In particular, heat is diffused in two distinct, but coupled, channels. Conventional single fluid models neglect the resulting complexity, and can often inaccurately interpret the results of heat pulse experiments. However, by recognizing the sensitivity of the electron temperature evolution to the ion diffusivity, not only can previous experiments be interpreted correctly, but informative simultaneous measurements can be made of both ion and electron heat channels.
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Affiliation(s)
- S Jin
- Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08544, USA
| | - A H Reiman
- Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08544, USA
| | - N J Fisch
- Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08544, USA
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3
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Leuterer F, MÜnich M, Brandl F, Brinkschulte H, GrÜnwald G, Manini A, Monaco F, Ryter F, SchÜtz H, Stober J, Wagner D, Kasparek W, Gantenbein G, Empacher L, Lechte C, Kumric H, SchÜller P, Litvak A, Chirkov A, Denisov G, Fix A, Illin V, Malygin S, Miasnikov V, Nichiporenko V, Popov L, Tai E, Zapevalov V. Operation Experience with the ASDEX Upgrade ECRH System. FUSION SCIENCE AND TECHNOLOGY 2017. [DOI: 10.13182/fst09-a4051] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- F. Leuterer
- Max-Planck-Institut für Plasmaphysik, Association Euratom-IPP, D-85748 Garching, Germany
| | - M. MÜnich
- Max-Planck-Institut für Plasmaphysik, Association Euratom-IPP, D-85748 Garching, Germany
| | - F. Brandl
- Max-Planck-Institut für Plasmaphysik, Association Euratom-IPP, D-85748 Garching, Germany
| | - H. Brinkschulte
- Max-Planck-Institut für Plasmaphysik, Association Euratom-IPP, D-85748 Garching, Germany
| | - G. GrÜnwald
- Max-Planck-Institut für Plasmaphysik, Association Euratom-IPP, D-85748 Garching, Germany
| | - A. Manini
- Max-Planck-Institut für Plasmaphysik, Association Euratom-IPP, D-85748 Garching, Germany
| | - F. Monaco
- Max-Planck-Institut für Plasmaphysik, Association Euratom-IPP, D-85748 Garching, Germany
| | - F. Ryter
- Max-Planck-Institut für Plasmaphysik, Association Euratom-IPP, D-85748 Garching, Germany
| | - H. SchÜtz
- Max-Planck-Institut für Plasmaphysik, Association Euratom-IPP, D-85748 Garching, Germany
| | - J. Stober
- Max-Planck-Institut für Plasmaphysik, Association Euratom-IPP, D-85748 Garching, Germany
| | - D. Wagner
- Max-Planck-Institut für Plasmaphysik, Association Euratom-IPP, D-85748 Garching, Germany
| | - W. Kasparek
- Institut für Plasmaforschung, Universität Stuttgart, D-70569 Stuttgart, Germany
| | - G. Gantenbein
- Institut für Plasmaforschung, Universität Stuttgart, D-70569 Stuttgart, Germany
| | - L. Empacher
- Institut für Plasmaforschung, Universität Stuttgart, D-70569 Stuttgart, Germany
| | - C. Lechte
- Institut für Plasmaforschung, Universität Stuttgart, D-70569 Stuttgart, Germany
| | - H. Kumric
- Institut für Plasmaforschung, Universität Stuttgart, D-70569 Stuttgart, Germany
| | - P. SchÜller
- Institut für Plasmaforschung, Universität Stuttgart, D-70569 Stuttgart, Germany
| | - A. Litvak
- Institute of Applied Physics, RAS, 603950 Nizhny Novgorod, Russia
| | - A. Chirkov
- Institute of Applied Physics, RAS, 603950 Nizhny Novgorod, Russia
| | - G. Denisov
- Institute of Applied Physics, RAS, 603950 Nizhny Novgorod, Russia
| | - A. Fix
- Institute of Applied Physics, RAS, 603950 Nizhny Novgorod, Russia
| | - V. Illin
- Institute of Applied Physics, RAS, 603950 Nizhny Novgorod, Russia
| | - S. Malygin
- Institute of Applied Physics, RAS, 603950 Nizhny Novgorod, Russia
| | - V. Miasnikov
- Institute of Applied Physics, RAS, 603950 Nizhny Novgorod, Russia
| | - V. Nichiporenko
- Institute of Applied Physics, RAS, 603950 Nizhny Novgorod, Russia
| | - L. Popov
- Institute of Applied Physics, RAS, 603950 Nizhny Novgorod, Russia
| | - E. Tai
- Institute of Applied Physics, RAS, 603950 Nizhny Novgorod, Russia
| | - V. Zapevalov
- Institute of Applied Physics, RAS, 603950 Nizhny Novgorod, Russia
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4
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Esposito B, Buratti P, Cirant S, Leigheb M, Bracco G, Carraro L, Cocilovo V, Gabellieri L, Gandini F, Giovannozzi E, Gormezano C, Jacchia A, Lazzaro E, Luca FD, Marinucci M, Minardi E, Nowak S, Pacella D, Panaccione L, Romanelli M, Sozzi C, Tudisco O. Chapter 6: Transport Studies in the FTU. FUSION SCIENCE AND TECHNOLOGY 2017. [DOI: 10.13182/fst04-a520] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- B. Esposito
- Associazione EURATOM-ENEA sulla Fusione, CR Frascati, Roma, Italy
| | - P. Buratti
- Associazione EURATOM-ENEA sulla Fusione, CR Frascati, Roma, Italy
| | - S. Cirant
- Associazione EURATOM-ENEA-CNR sulla Fusione, Istituto di Fisica del Plasma, Milano, Italy
| | - M. Leigheb
- Associazione EURATOM-ENEA sulla Fusione, CR Frascati, Roma, Italy
| | - G. Bracco
- Associazione EURATOM-ENEA sulla Fusione, CR Frascati, Roma, Italy
| | - L. Carraro
- Associazione EURATOM-ENEA-CNR sulla Fusione, Consorzio RFX, Corso Stati Uniti 4 1-35100, Padova, Italy
| | - V. Cocilovo
- Associazione EURATOM-ENEA sulla Fusione, CR Frascati, Roma, Italy
| | - L. Gabellieri
- Associazione EURATOM-ENEA sulla Fusione, CR Frascati, Roma, Italy
| | - F. Gandini
- Associazione EURATOM-ENEA-CNR sulla Fusione, Istituto di Fisica del Plasma, Milano, Italy
| | - E. Giovannozzi
- Associazione EURATOM-ENEA sulla Fusione, CR Frascati, Roma, Italy
| | - C. Gormezano
- Associazione EURATOM-ENEA sulla Fusione, CR Frascati, Roma, Italy
| | - A. Jacchia
- Associazione EURATOM-ENEA-CNR sulla Fusione, Istituto di Fisica del Plasma, Milano, Italy
| | - E. Lazzaro
- Associazione EURATOM-ENEA-CNR sulla Fusione, Istituto di Fisica del Plasma, Milano, Italy
| | - F. de Luca
- Associazione EURATOM-ENEA-CNR sulla Fusione, Istituto di Fisica del Plasma, Milano, Italy
| | - M. Marinucci
- Associazione EURATOM-ENEA sulla Fusione, CR Frascati, Roma, Italy
| | - E. Minardi
- Associazione EURATOM-ENEA-CNR sulla Fusione, Istituto di Fisica del Plasma, Milano, Italy
| | - S. Nowak
- Associazione EURATOM-ENEA-CNR sulla Fusione, Istituto di Fisica del Plasma, Milano, Italy
| | - D. Pacella
- Associazione EURATOM-ENEA sulla Fusione, CR Frascati, Roma, Italy
| | - L. Panaccione
- Associazione EURATOM-ENEA sulla Fusione, CR Frascati, Roma, Italy
| | - M. Romanelli
- Associazione EURATOM-ENEA sulla Fusione, CR Frascati, Roma, Italy
| | - C Sozzi
- Associazione EURATOM-ENEA-CNR sulla Fusione, Istituto di Fisica del Plasma, Milano, Italy
| | - O. Tudisco
- Associazione EURATOM-ENEA sulla Fusione, CR Frascati, Roma, Italy
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5
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Gormezano C, Buratti P, Apicella ML, Barbato E, Bracco G, Cardinali A, Castaldo C, Cesario R, Cirant S, Crisanti F, Benedetti MD, Esposito B, Frigione D, Gabellieri L, Giovannozzi E, Granucci G, Kroegler H, Leigheb M, Marinucci M, Pacella D, Panaccione L, Pericoli-Ridolfini P, Pieroni L, Podda S, Romanelli F, Romanelli M, Smeulders P, Sozzi C, Tuccillo AA, Tudisco O. Chapter 2: Highlights of the Physics Studies in the FTU. FUSION SCIENCE AND TECHNOLOGY 2017. [DOI: 10.13182/fst04-a516] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- C. Gormezano
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - P. Buratti
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - M. L. Apicella
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - E. Barbato
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - G. Bracco
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - A. Cardinali
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - C. Castaldo
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - R. Cesario
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - S. Cirant
- Associazione EURATOM-ENEA-CNR sulla Fusione, Istituto di Fisica del Plasma Milano, Italy
| | - F. Crisanti
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - M. de Benedetti
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - B. Esposito
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - D. Frigione
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - L. Gabellieri
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - E. Giovannozzi
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - G. Granucci
- Associazione EURATOM-ENEA-CNR sulla Fusione, Istituto di Fisica del Plasma Milano, Italy
| | - H. Kroegler
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - M. Leigheb
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - M. Marinucci
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - D. Pacella
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - L. Panaccione
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | | | - L. Pieroni
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - S. Podda
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - F. Romanelli
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - M. Romanelli
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - P. Smeulders
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - C. Sozzi
- Associazione EURATOM-ENEA-CNR sulla Fusione, Istituto di Fisica del Plasma Milano, Italy
| | - A. A. Tuccillo
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
| | - O. Tudisco
- Associazione EURATOM-ENEA sulla fusione, CR Frascati, Roma, Italy
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6
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Moon C, Kaneko T, Hatakeyama R. Dynamics of nonlinear coupling between electron-temperature-gradient mode and drift-wave mode in linear magnetized plasmas. PHYSICAL REVIEW LETTERS 2013; 111:115001. [PMID: 24074096 DOI: 10.1103/physrevlett.111.115001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 04/26/2013] [Indexed: 06/02/2023]
Abstract
A high-frequency (∼0.4 MHz) fluctuation is excited by an electron temperature gradient (ETG) perpendicular to magnetic field lines, which is consistent with an ETG mode. When the fluctuation amplitude of the ETG mode exceeds a certain threshold, the mode gradually becomes saturated and a low-frequency (∼7 kHz) fluctuation which is originally caused by a drift wave is enhanced, corresponding to the saturation of the ETG mode. In addition, a nonlinear coupling, specifically, the bicoherence between the ETG mode and the drift wave mode, begins to increase when the ETG strength exceeds the threshold, which simultaneously occurs with the saturation of the ETG mode. Thus, it was determined that the ETG mode stimulates the drift wave mode excitement via multiscale nonlinear interaction between the high-frequency (∼MHz) and low-frequency (∼kHz) fluctuations, which ultimately causes ETG mode energy to be transferred to the drift wave mode.
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Affiliation(s)
- Chanho Moon
- Department of Electronic Engineering, Tohoku University, 6-6-05 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
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7
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Hidalgo C, Silva C, Carreras BA, van Milligen B, Figueiredo H, García L, Pedrosa MA, Gonçalves B, Alonso A. Dynamical coupling between gradients and transport in fusion plasmas. PHYSICAL REVIEW LETTERS 2012; 108:065001. [PMID: 22401076 DOI: 10.1103/physrevlett.108.065001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Indexed: 05/31/2023]
Abstract
The dynamical coupling between density gradients and particle transport has been investigated using similar experimental tools in the plasma boundary of different tokamak (JET, ISTTOK) and stellarator (TJ-II) devices, showing that the size of turbulent events is minimum in the proximity of the most probable density gradient. Experimental results were found to be consistent with results from two very different models of plasma turbulence and transport. The present findings, common to several plasma devices, suggest the importance of self-regulation mechanisms between plasma transport and gradients in fusion devices.
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8
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Hogeweij G. Transport Studies Using Perturbative Experiments. FUSION SCIENCE AND TECHNOLOGY 2012. [DOI: 10.13182/fst12-a13502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- G.M.D. Hogeweij
- FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O.Box 1207, 3430 BE Nieuwegein, The Netherlands,
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9
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Xiao WW, Zou XL, Ding XT, Yao LH, Feng BB, Song XM, Song SD, Zhou Y, Liu ZT, Yuan BS, Sun HJ, Ji XQ, Gao YD, Li YG, Yan LW, Yang QW, Liu Y, Dong JQ, Duan XR, Liu Y, Pan CH. Observation of a spontaneous particle-transport barrier in the HL-2A tokamak. PHYSICAL REVIEW LETTERS 2010; 104:215001. [PMID: 20867107 DOI: 10.1103/physrevlett.104.215001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2008] [Indexed: 05/29/2023]
Abstract
Using the profile analysis, the density perturbation transport analysis, and the Doppler reflectometry measurement, for the first time a spontaneous and steady-state particle-transport barrier has been evidenced in the Ohmic plasmas in the HL-2A tokamak with no externally applied momentum or particle input except the gas puffing. A threshold in density has been found for the observation of the barrier. The particle diffusivity is well-like, and the convection is found to be inward outside the well and outward inside the well. The formation of the barrier coincides with the transition between the trapped electron mode and the ion temperature gradient driven mode.
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Affiliation(s)
- W W Xiao
- Southwestern Institute of Physics, P.O. Box 432, Chengdu, China
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10
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Hogeweij G. Transport Studies Using Perturbative Experiments. FUSION SCIENCE AND TECHNOLOGY 2010. [DOI: 10.13182/fst10-a9426] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- G.M.D. Hogeweij
- FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O.Box 1207, 3430 BE Nieuwegein, The Netherlands,
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11
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Xiao WW, Zou XL, Ding XT, Dong JQ, Yao LH, Song SD, Liu ZT, Gao YD, Feng BB, Song XM, Yang QW, Yan LW, Liu Y, Duan XR, Pan CH, Liu Y. A method of particle transport study using supersonic molecular beam injection and microwave reflectometry on HL-2A tokamak. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2010; 81:013506. [PMID: 20113099 DOI: 10.1063/1.3274201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A method of the particle transport study using supersonic molecular beam injection (SMBI) and microwave reflectometry is reported in this paper. Experimental results confirm that pulsed SMBI is a good perturbation source with deeper penetration and better localization than the standard gas puffing. The local density modulation is induced using the pulsed SMBI and the perturbation density is measured by the microwave reflectometry. Using Fourier transform analysis for the local density perturbation, radial profiles of the amplitude and phase of the density modulation can be obtained. The experimental results in HL-2A show that the particle injected by SMBI is located at about r/a=0.65-0.75. The position of the main particle source can be determined through three aspects: the minimum of the phase of the first harmonic of the Fourier transform of the modulated density measured by microwave reflectometry; the H(a) intensity profile and the local density increase ratio. The maximum of the amplitude of the first harmonic shifts often inward relative to the particle source location, which indicates clearly there is an inward particle pinch in this area. Good agreement has been found between the experimental results and the simulation using analytical transport model. The particle diffusivity D and the particle convection velocity V have been obtained by doing this simulation. The sensitivity in the transport coefficients of the amplitude and the phase of the density modulation has been discussed.
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Affiliation(s)
- W W Xiao
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, People's Republic of China.
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12
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Hogeweij G. Transport Studies Using Perturbative Experiments. FUSION SCIENCE AND TECHNOLOGY 2008. [DOI: 10.13182/fst08-a1719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- G.M.D. Hogeweij
- FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O.Box 1207, 3430 BE Nieuwegein, The Netherlands
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13
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Mantica P, Van Eester D, Garbet X, Imbeaux F, Laborde L, Mantsinen M, Marinoni A, Mazon D, Moreau D, Hawkes N, Joffrin E, Kiptily V, Pinches S, Salmi A, Sharapov S, Thyagaraja A, Voitsekhovitch I, de Vries P, Zastrow KD. Probing internal transport barriers with heat pulses in JET. PHYSICAL REVIEW LETTERS 2006; 96:095002. [PMID: 16606270 DOI: 10.1103/physrevlett.96.095002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2005] [Indexed: 05/08/2023]
Abstract
The first electron temperature modulation experiments in plasmas characterized by strong and long-lasting electron and ion internal transport barriers (ITB) have been performed in JET using ion cyclotron resonance heating in mode conversion scheme. The ITB is shown to be a well localized narrow layer with low heat diffusivity, characterized by subcritical transport and loss of stiffness. In addition, results from cold pulse propagation experiments suggest a second order transition process for ITB formation.
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Affiliation(s)
- P Mantica
- Istituto di Fisica del Plasma P.Caldirola, Associazione Euratom-ENEA-CNR, Milano, Italy
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14
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Hogeweij G. Transport Studies Using Perturbative Experiments. FUSION SCIENCE AND TECHNOLOGY 2006. [DOI: 10.13182/fst06-a1128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- G.M.D. Hogeweij
- FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O.Box 1207, 3430 BE Nieuwegein, The Netherlands,
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15
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Wolf RC. A Tokamak Reactor Based on Advanced Concepts. FUSION SCIENCE AND TECHNOLOGY 2006. [DOI: 10.13182/fst06-a1143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- R. C. Wolf
- Institut f¨ur Plasmaphysik, Forschungszentrum J¨ulich, EURATOM Assocation/FZJ, Trilateral Euregio Cluster, D-52425 J¨ulich, Germany
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16
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Ryter F, Angioni C, Peeters AG, Leuterer F, Fahrbach HU, Suttrop W. Experimental study of trapped-electron-mode properties in tokamaks: threshold and stabilization by collisions. PHYSICAL REVIEW LETTERS 2005; 95:085001. [PMID: 16196865 DOI: 10.1103/physrevlett.95.085001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2005] [Indexed: 05/04/2023]
Abstract
Trapped electron modes are one of the candidates to explain turbulence driven electron heat transport observed in tokamaks. This instability has two characteristics: a threshold in normalized gradient and stabilization by collisions. Experiments using modulated electron cyclotron heating in the ASDEX Upgrade tokamak demonstrate explicitly the existence of the threshold. The stabilization with increasing collisionality is evidenced by a strong decrease of the propagation of heat pulses, explained by a transition to ion temperature gradient driven transport. These results are supported by linear gyrokinetic calculations.
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Affiliation(s)
- F Ryter
- Max-Planck-Institut für Plasmaphysik, EURATOM Association, D-85748 Garching, Germany
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17
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Hoang GT, Bourdelle C, Garbet X, Artaud JF, Basiuk V, Bucalossi J, Clairet F, Fenzi-Bonizec C, Gil C, Ségui JL, Travère JM, Tsitrone E, Vermare L. Parametric dependence of turbulent particle transport in tore supra plasmas. PHYSICAL REVIEW LETTERS 2004; 93:135003. [PMID: 15524729 DOI: 10.1103/physrevlett.93.135003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2004] [Indexed: 05/24/2023]
Abstract
Steady state full noninductive current tore supra plasmas offer a unique opportunity to study the local parametric dependence of particle pinch velocity, in order to discriminate among different theories. Magnetic field shear is found to generate an inward pinch which is dominant in the gradient region (normalized radius 0.3</=r/a</=0.6). In contrast, the direction of the pinch in the plasma core (r/a</=0.3) is correlated with the electron temperature gradient length. The results are in agreement with both the turbulent theoretical and computational predictions.
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Affiliation(s)
- G T Hoang
- Euratom-CEA Association, CEA/DSM/DRFC, CEA Cadarache F-13108, Saint-Paul-Lez-Durance, France
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18
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Wolf RC. A Tokamak Reactor Based on Advanced Concepts. FUSION SCIENCE AND TECHNOLOGY 2004. [DOI: 10.13182/fst04-a514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- R. C. Wolf
- Institut für Plasmaphysik, Forschungszentrum Jülich, EURATOM Assocation/FZJ, Trilateral Euregio Cluster, D-52425 Jülich, Germany
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19
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Kim EJ, Holland C, Diamond PH. Collisional damping of ETG-mode-driven zonal flows. PHYSICAL REVIEW LETTERS 2003; 91:075003. [PMID: 12935026 DOI: 10.1103/physrevlett.91.075003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2003] [Indexed: 05/24/2023]
Abstract
We study collisional damping of electron zonal flows in toroidal electron temperature gradient (ETG) turbulence due to the friction between trapped and untrapped electrons. With the assumption of adiabatic ions, the collisional damping is shown to occur on fast time scales approximately 0.24epsilon(1/2)tau(e). The comparison with the growth rate of electron zonal flows indicates that the shearing by electron zonal flows is unlikely to be a robust mechanism for regulating ETG turbulence. This finding vitiates the claims of several simulation studies that have ignored the effects of collisional damping of electron zonal flows and offers a possible partial explanation of the high levels of electron thermal transport observed in the National Spherical Torus Experiment.
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Affiliation(s)
- Eun-jin Kim
- Department of Physics, University of California-San Diego, La Jolla, CA 92093-0319, USA
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20
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Tangri V, Das A, Kaw P, Singh R. Continuum self-organized-criticality model of turbulent heat transport in tokamaks. PHYSICAL REVIEW LETTERS 2003; 91:025001. [PMID: 12906484 DOI: 10.1103/physrevlett.91.025001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2002] [Indexed: 05/24/2023]
Abstract
A simple generic one-dimensional continuum model of driven dissipative systems is proposed to explain self-organized bursty heat transport in tokamaks. Extensive numerical simulations of this model reproduce many features of present day tokamaks such as submarginal temperature profiles, intermittent transport events, 1/f scaling of the frequency spectra, propagating fronts, etc. This model utilizes a minimal set of phenomenological parameters, which may be determined from experiments and/or simulations. Analytical and physical understanding of the observed features has also been attempted.
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Affiliation(s)
- Varun Tangri
- Institute for Plasma Research, Bhat, Gandhinagar 382428, India
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21
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Ryter F, Imbeaux F, Leuterer F, Fahrbach HU, Suttrop W. Experimental characterization of the electron heat transport in low-density ASDEX upgrade plasmas. PHYSICAL REVIEW LETTERS 2001; 86:5498-5501. [PMID: 11415285 DOI: 10.1103/physrevlett.86.5498] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2000] [Indexed: 05/23/2023]
Abstract
The electron heat transport is investigated in ASDEX Upgrade conventional L-mode plasmas with pure electron heating provided by electron-cyclotron heating (ECH) at low density. Under these conditions, steady-state and ECH modulation experiments indicate without ambiguity that electron heat transport exhibits a clear threshold in inverted Delta T(e)/T(e) and also suggest that it has a gyro-Bohm character.
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Affiliation(s)
- F Ryter
- Max-Planck-Institut für Plasmaphysik, EURATOM Association, D-85748 Garching, Germany
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