1
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Morales RB, Salmi A, Abreu P, Amador CHS, Appel L, Carman P, Fessey J, Flanagan J, Fontana M, Frassinetti L, Giroud C, Hacquin S, Heuraux S, Meneses L, Ronchi G, Sabot R, Silva A, Sirinelli A, Szepesi G, Taylor D, Terranova D. Improved accuracy and robustness of electron density profiles from JET's X-mode frequency-modulated continuous-wave reflectometers. Rev Sci Instrum 2024; 95:043501. [PMID: 38557886 DOI: 10.1063/5.0176696] [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: 09/15/2023] [Accepted: 03/13/2024] [Indexed: 04/04/2024]
Abstract
JET's frequency-modulated continuous wave (FMCW) reflectometers have been operating well with the current design since 2005, and density profiles have been automatically calculated intershot since then. However, the calculated profiles had long suffered from several shortcomings: poor agreement with other diagnostics, sometimes inappropriately moving radially by several centimeters, elevated levels of radial jitter, and persistent wriggles (strong unphysical oscillations). In this research, several techniques are applied to the reflectometry data analysis, and the shortcomings are significantly improved. Starting with improving the equilibrium reconstruction that estimates the background magnetic field, adding a ripple correction in the reconstructed magnetic field profile, and adding new inner-wall reflection positions estimated through ray-tracing, these changes not only improve the agreement of reconstructed profiles to other diagnostics but also solve density profile wriggles that were present during band transitions. Other smaller but also persistent wriggles were also suppressed by applying a localized correction to the measured beat frequency where persistent oscillations are present. Finally, the burst analysis method, as introduced by Varela et al. [Nucl. Fusion 46 S693 (2006)], has been implemented to extract the beat frequency from stacked spectrograms. Due to the strong suppression of spurious reflections, the radial jitter that sometimes would span several centimeters has been strongly reduced. The stacking of spectrograms has also been shown to be very useful for stacking recurring events, like small gas puff modulations, and extracting transport coefficients that would otherwise be below the noise level.
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Affiliation(s)
- R B Morales
- UKAEA (United Kingdom Atomic Energy Authority), Culham Campus, Abingdon, Oxfordshire OX14 3DB, United Kingdom
| | - A Salmi
- VTT, P.O. Box 1000, FI-02044 VTT Espoo, Finland
| | - P Abreu
- IPFN, Instituto Superior Técnico da Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - C H S Amador
- Federal University of Technology-Parana (UTFPR), Department of Natural Sciences, Cornélio Procópio, Brazil
| | - L Appel
- UKAEA (United Kingdom Atomic Energy Authority), Culham Campus, Abingdon, Oxfordshire OX14 3DB, United Kingdom
| | - P Carman
- UKAEA (United Kingdom Atomic Energy Authority), Culham Campus, Abingdon, Oxfordshire OX14 3DB, United Kingdom
| | - J Fessey
- UKAEA (United Kingdom Atomic Energy Authority), Culham Campus, Abingdon, Oxfordshire OX14 3DB, United Kingdom
| | - J Flanagan
- UKAEA (United Kingdom Atomic Energy Authority), Culham Campus, Abingdon, Oxfordshire OX14 3DB, United Kingdom
| | - M Fontana
- UKAEA (United Kingdom Atomic Energy Authority), Culham Campus, Abingdon, Oxfordshire OX14 3DB, United Kingdom
| | - L Frassinetti
- Division of Electromagnetic Engineering and Fusion Science, KTH, Stockholm 100 44, Sweden
| | - C Giroud
- UKAEA (United Kingdom Atomic Energy Authority), Culham Campus, Abingdon, Oxfordshire OX14 3DB, United Kingdom
| | - S Hacquin
- IRFM, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - S Heuraux
- IJL, University of Lorraine, UMR 7198 CNRS, BP 50840, 54011 Nancy Cedex, France
| | - L Meneses
- ITER Organization, Route de Vinon, CS 90 046, 13067 Saint-Paul-Lez-Durance, France
| | - G Ronchi
- Oak Ridge National Laboratory, Oak Ridge, Tennessee, Tennessee 37830, USA
| | - R Sabot
- IRFM, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - A Silva
- IPFN, Instituto Superior Técnico da Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - A Sirinelli
- ITER Organization, Route de Vinon, CS 90 046, 13067 Saint-Paul-Lez-Durance, France
| | - G Szepesi
- UKAEA (United Kingdom Atomic Energy Authority), Culham Campus, Abingdon, Oxfordshire OX14 3DB, United Kingdom
| | - D Taylor
- UKAEA (United Kingdom Atomic Energy Authority), Culham Campus, Abingdon, Oxfordshire OX14 3DB, United Kingdom
| | - D Terranova
- Consorzio RFX and ISTP-CNR, Corso Stati Uniti 4, 35127 Padova, Italy
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Field AR, Chapman-Oplopoiou B, Connor JW, Frassinetti L, Hatch DR, Roach CM, Saarelma S. Comparing pedestal structure in JET-ILW H-mode plasmas with a model for stiff ETG turbulent heat transport. Philos Trans A Math Phys Eng Sci 2023; 381:20210228. [PMID: 36587822 PMCID: PMC9805819 DOI: 10.1098/rsta.2021.0228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 05/20/2022] [Indexed: 06/17/2023]
Abstract
A predictive model for the electron temperature profile of the H-mode pedestal is described, and its results are compared with the pedestal structure of JET-ILW plasmas. The model is based on a scaling for the gyro-Bohm normalized, turbulent electron heat flux [Formula: see text] resulting from electron temperature gradient (ETG) turbulence, derived from results of nonlinear gyrokinetic (GK) calculations for the steep gradient region. By using the local temperature gradient scale length [Formula: see text] in the normalization, the dependence of [Formula: see text] on the normalized gradients [Formula: see text] and [Formula: see text] can be represented by a unified scaling with the parameter [Formula: see text], to which the linear stability of ETG turbulence is sensitive when the density gradient is sufficiently steep. For a prescribed density profile, the value of [Formula: see text] determined from this scaling, required to maintain a constant electron heat flux [Formula: see text] across the pedestal, is used to calculate the temperature profile. Reasonable agreement with measurements is found for different cases, the model providing an explanation of the relative widths and shifts of the [Formula: see text] and [Formula: see text] profiles, as well as highlighting the importance of the separatrix boundary conditions. Other cases showing disagreement indicate conditions where other branches of turbulence might dominate. This article is part of a discussion meeting issue 'H-mode transition and pedestal studies in fusion plasmas'.
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Affiliation(s)
- A. R. Field
- United Kingdom Atomic Energy Authority, Culham Centre for Fusion Energy, Culham Science Centre, Abingdon, Oxon OX14 3DB, UK
| | - B. Chapman-Oplopoiou
- United Kingdom Atomic Energy Authority, Culham Centre for Fusion Energy, Culham Science Centre, Abingdon, Oxon OX14 3DB, UK
| | - J. W. Connor
- United Kingdom Atomic Energy Authority, Culham Centre for Fusion Energy, Culham Science Centre, Abingdon, Oxon OX14 3DB, UK
| | - L. Frassinetti
- Division of Fusion Plasma Physics, KTH Royal Institute of Technology SE-100 44 Stockholm, Sweden
| | - D. R. Hatch
- Institute for Fusion Studies, University of Texas at Austin, Austin, TX 78712, USA
| | - C. M. Roach
- United Kingdom Atomic Energy Authority, Culham Centre for Fusion Energy, Culham Science Centre, Abingdon, Oxon OX14 3DB, UK
| | - S. Saarelma
- United Kingdom Atomic Energy Authority, Culham Centre for Fusion Energy, Culham Science Centre, Abingdon, Oxon OX14 3DB, UK
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Simpson J, Moulton D, Giroud C, Groth M, Horvath L, Casson F, Kochl F, Frassinetti L, Corrigan G, Saarelma D, Garzotti L, Gahle S, Chankin A. Investigation of the dependence of pe,ped on ne,sep in JET H-Mode plasmas using integrated JETTO-MISHKA-FRANTIC simulations. Nuclear Materials and Energy 2023. [DOI: 10.1016/j.nme.2023.101365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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4
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Kit A, Järvinen A, Wiesen S, Poels Y, Frassinetti L. Developing deep learning algorithms for inferring upstream separatrix density at JET. Nuclear Materials and Energy 2022. [DOI: 10.1016/j.nme.2022.101347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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5
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Kumpulainen H, Groth M, Brezinsek S, Corrigan G, Frassinetti L, Harting D, Koechl F, Karhunen J, Meigs A, O'Mullane M, Romazanov J. ELM and inter-ELM tungsten erosion sources in high-power, JET ITER-like wall H-mode plasmas. Nuclear Materials and Energy 2022. [DOI: 10.1016/j.nme.2022.101264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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6
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Sheikh U, Dunne M, Frassinetti L, Labit B, Blanchard P, Duval B, Février O, Galassi D, Merle A, Reimerdes H, Theiler C. Impact of the new TCV baffled divertor upgrade on pedestal structure and performance. Nuclear Materials and Energy 2021. [DOI: 10.1016/j.nme.2021.100933] [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: 11/30/2022]
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Wiesen S, Brezinsek S, Bonnin X, Delabie E, Frassinetti L, Groth M, Guillemaut C, Harrison J, Harting D, Henderson S, Huber A, Kruezi U, Pitts R, Wischmeier M. On the role of finite grid extent in SOLPS-ITER edge plasma simulations for JET H-mode discharges with metallic wall. Nuclear Materials and Energy 2018. [DOI: 10.1016/j.nme.2018.10.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [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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8
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Fridström R, Chapman BE, Almagri AF, Frassinetti L, Brunsell PR, Nishizawa T, Sarff JS. Dependence of Perpendicular Viscosity on Magnetic Fluctuations in a Stochastic Topology. Phys Rev Lett 2018; 120:225002. [PMID: 29906181 DOI: 10.1103/physrevlett.120.225002] [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: 12/05/2017] [Revised: 03/21/2018] [Indexed: 06/08/2023]
Abstract
In a magnetically confined plasma with a stochastic magnetic field, the dependence of the perpendicular viscosity on the magnetic fluctuation amplitude is measured for the first time. With a controlled, ∼ tenfold variation in the fluctuation amplitude, the viscosity increases ∼100-fold, exhibiting the same fluctuation-amplitude-squared dependence as the predicted rate of stochastic field line diffusion. The absolute value of the viscosity is well predicted by a model based on momentum transport in a stochastic field, the first in-depth test of this model.
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Affiliation(s)
- R Fridström
- Department of Fusion Plasma Physics, School of Electrical Engineering, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden
| | - B E Chapman
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA
| | - A F Almagri
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA
| | - L Frassinetti
- Department of Fusion Plasma Physics, School of Electrical Engineering, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden
| | - P R Brunsell
- Department of Fusion Plasma Physics, School of Electrical Engineering, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden
| | - T Nishizawa
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA
| | - J S Sarff
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA
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9
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Setiadi A, Brunsell P, Villone F, Mastrostefano S, Frassinetti L. Gray-box modeling of resistive wall modes with vacuum-plasma separation and optimal control design for EXTRAP T2R. Fusion Engineering and Design 2017. [DOI: 10.1016/j.fusengdes.2017.07.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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Leyland MJ, Beurskens MNA, Flanagan JC, Frassinetti L, Gibson KJ, Kempenaars M, Maslov M, Scannell R. Edge profile analysis of Joint European Torus (JET) Thomson scattering data: Quantifying the systematic error due to edge localised mode synchronisation. Rev Sci Instrum 2016; 87:013507. [PMID: 26827321 DOI: 10.1063/1.4939855] [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: 06/05/2023]
Abstract
The Joint European Torus (JET) high resolution Thomson scattering (HRTS) system measures radial electron temperature and density profiles. One of the key capabilities of this diagnostic is measuring the steep pressure gradient, termed the pedestal, at the edge of JET plasmas. The pedestal is susceptible to limiting instabilities, such as Edge Localised Modes (ELMs), characterised by a periodic collapse of the steep gradient region. A common method to extract the pedestal width, gradient, and height, used on numerous machines, is by performing a modified hyperbolic tangent (mtanh) fit to overlaid profiles selected from the same region of the ELM cycle. This process of overlaying profiles, termed ELM synchronisation, maximises the number of data points defining the pedestal region for a given phase of the ELM cycle. When fitting to HRTS profiles, it is necessary to incorporate the diagnostic radial instrument function, particularly important when considering the pedestal width. A deconvolved fit is determined by a forward convolution method requiring knowledge of only the instrument function and profiles. The systematic error due to the deconvolution technique incorporated into the JET pedestal fitting tool has been documented by Frassinetti et al. [Rev. Sci. Instrum. 83, 013506 (2012)]. This paper seeks to understand and quantify the systematic error introduced to the pedestal width due to ELM synchronisation. Synthetic profiles, generated with error bars and point-to-point variation characteristic of real HRTS profiles, are used to evaluate the deviation from the underlying pedestal width. We find on JET that the ELM synchronisation systematic error is negligible in comparison to the statistical error when assuming ten overlaid profiles (typical for a pre-ELM fit to HRTS profiles). This confirms that fitting a mtanh to ELM synchronised profiles is a robust and practical technique for extracting the pedestal structure.
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Affiliation(s)
- M J Leyland
- Department of Physics, York Plasma Institute, University of York, Heslington, York YO10 5DD, United Kingdom
| | - M N A Beurskens
- Max-Planck Institute für Plasma Physik, D-17491 Greifswald, Germany
| | - J C Flanagan
- CCFE, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB, United Kingdom
| | - L Frassinetti
- Division of Fusion Plasma Physics, KTH, SE-10044 Stockholm, Sweden
| | - K J Gibson
- Department of Physics, York Plasma Institute, University of York, Heslington, York YO10 5DD, United Kingdom
| | - M Kempenaars
- CCFE, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB, United Kingdom
| | - M Maslov
- CCFE, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB, United Kingdom
| | - R Scannell
- CCFE, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB, United Kingdom
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11
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Bohm P, Aftanas M, Bilkova P, Stefanikova E, Mikulin O, Melich R, Janky F, Havlicek J, Sestak D, Weinzettl V, Stockel J, Hron M, Panek R, Scannell R, Frassinetti L, Fassina A, Naylor G, Walsh MJ. Edge Thomson scattering diagnostic on COMPASS tokamak: installation, calibration, operation, improvements. Rev Sci Instrum 2014; 85:11E431. [PMID: 25430338 DOI: 10.1063/1.4893995] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The core Thomson scattering diagnostic (TS) on the COMPASS tokamak was put in operation and reported earlier. Implementation of edge TS, with spatial resolution along the laser beam up to ∼1/100 of the tokamak minor radius, is presented now. The procedure for spatial calibration and alignment of both core and edge systems is described. Several further upgrades of the TS system, like a triggering unit and piezo motor driven vacuum window shutter, are introduced as well. The edge TS system, together with the core TS, is now in routine operation and provides electron temperature and density profiles.
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Affiliation(s)
- P Bohm
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - M Aftanas
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - P Bilkova
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - E Stefanikova
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - O Mikulin
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - R Melich
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - F Janky
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - J Havlicek
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - D Sestak
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - V Weinzettl
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - J Stockel
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - M Hron
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - R Panek
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - R Scannell
- CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
| | - L Frassinetti
- School of Electrical Engineering, Division of Fusion Plasma Physics, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden
| | - A Fassina
- Consorzio RFX, Corso Stati Uniti, 4-35127 Padua, Italy
| | - G Naylor
- CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
| | - M J Walsh
- ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St Paul lez Durance, France
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12
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Frassinetti L, Beurskens MNA, Scannell R, Osborne TH, Flanagan J, Kempenaars M, Maslov M, Pasqualotto R, Walsh M. Spatial resolution of the JET Thomson scattering system. Rev Sci Instrum 2012; 83:013506. [PMID: 22299950 DOI: 10.1063/1.3673467] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The instrument function of the high resolution Thomson scattering (HRTS) diagnostic in the Joint European Torus (JET) has been calculated for use in improved pedestal profile analysis. The full width at half maximum (FWHM) of the spatial instrument response is (22 ± 1) mm for the original HRTS system configuration and depends on the particular magnetic topology of the JET plasmas. An improvement to the optical design of the laser input system is presented. The spatial smearing across magnetic flux surfaces is reduced in this design. The new input system has been implemented (from JPN 78742, July 2009) and the HRTS instrument function corresponding to the new configuration has been improved to approximately FWHM = (9.8 ± 0.8) mm. The reconstructed instrument kernels are used in combination with an ad hoc forward deconvolution procedure for pedestal analysis. This procedure produces good results for both the old and new setups, but the reliability of the deconvolved profiles is greatly reduced when the pedestal width is of the same order as, or less than the FWHM of the instrument kernel.
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Affiliation(s)
- L Frassinetti
- JET-EFDA, Culham Science Centre, Abingdon, United Kingdom
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13
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Mantica P, Angioni C, Challis C, Colyer G, Frassinetti L, Hawkes N, Johnson T, Tsalas M, deVries PC, Weiland J, Baiocchi B, Beurskens MNA, Figueiredo ACA, Giroud C, Hobirk J, Joffrin E, Lerche E, Naulin V, Peeters AG, Salmi A, Sozzi C, Strintzi D, Staebler G, Tala T, Van Eester D, Versloot T. A key to improved ion core confinement in the JET tokamak: ion stiffness mitigation due to combined plasma rotation and low magnetic shear. Phys Rev Lett 2011; 107:135004. [PMID: 22026864 DOI: 10.1103/physrevlett.107.135004] [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: 05/13/2011] [Indexed: 05/31/2023]
Abstract
New transport experiments on JET indicate that ion stiffness mitigation in the core of a rotating plasma, as described by Mantica et al. [Phys. Rev. Lett. 102, 175002 (2009)] results from the combined effect of high rotational shear and low magnetic shear. The observations have important implications for the understanding of improved ion core confinement in advanced tokamak scenarios. Simulations using quasilinear fluid and gyrofluid models show features of stiffness mitigation, while nonlinear gyrokinetic simulations do not. The JET experiments indicate that advanced tokamak scenarios in future devices will require sufficient rotational shear and the capability of q profile manipulation.
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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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Frassinetti L, Predebon I, Koguchi H, Yagi Y, Hirano Y, Sakakita H, Spizzo G, White RB. Improved particle confinement in transition from multiple-helicity to quasi-single-helicity regimes of a reversed-field pinch. Phys Rev Lett 2006; 97:175001. [PMID: 17155477 DOI: 10.1103/physrevlett.97.175001] [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] [Received: 09/13/2005] [Indexed: 05/12/2023]
Abstract
The quasi-single-helicity (QSH) state of a reversed-field pinch (RFP) plasma is a regime in which the RFP configuration can be sustained by a dynamo produced mainly by a single tearing mode and in which a helical structure with well-defined magnetic flux surfaces arises. In this Letter, we show that spontaneous transitions to the QSH regime enhance the particle confinement. This improvement is originated by the simultaneous and cooperative action of the increase of the magnetic island and the reduction of the magnetic stochasticity.
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Affiliation(s)
- L Frassinetti
- National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan
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Calabro F, Sternberg CN, Lorusso V, Frassinetti L, Rosati G, Sava T, Guida M, Giovannini N, Manzione L, Donato Di Paola E, Alonso S. Multicenter phase II study of every-2 week gemcitabine and paclitaxel as first-line chemotherapy in patients with advanced urothelial tract cancer. J Clin Oncol 2005. [DOI: 10.1200/jco.2005.23.16_suppl.4583] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- F. Calabro
- San Camillo and Forlanini Hospitals, Rome, Italy; Inst di Oncologia, Bari, Italy; AUSL Forli, Forli, Italy; Osp San Carlo, Potenza, Italy; Univ of Verona, Verona, Italy
| | - C. N. Sternberg
- San Camillo and Forlanini Hospitals, Rome, Italy; Inst di Oncologia, Bari, Italy; AUSL Forli, Forli, Italy; Osp San Carlo, Potenza, Italy; Univ of Verona, Verona, Italy
| | - V. Lorusso
- San Camillo and Forlanini Hospitals, Rome, Italy; Inst di Oncologia, Bari, Italy; AUSL Forli, Forli, Italy; Osp San Carlo, Potenza, Italy; Univ of Verona, Verona, Italy
| | - L. Frassinetti
- San Camillo and Forlanini Hospitals, Rome, Italy; Inst di Oncologia, Bari, Italy; AUSL Forli, Forli, Italy; Osp San Carlo, Potenza, Italy; Univ of Verona, Verona, Italy
| | - G. Rosati
- San Camillo and Forlanini Hospitals, Rome, Italy; Inst di Oncologia, Bari, Italy; AUSL Forli, Forli, Italy; Osp San Carlo, Potenza, Italy; Univ of Verona, Verona, Italy
| | - T. Sava
- San Camillo and Forlanini Hospitals, Rome, Italy; Inst di Oncologia, Bari, Italy; AUSL Forli, Forli, Italy; Osp San Carlo, Potenza, Italy; Univ of Verona, Verona, Italy
| | - M. Guida
- San Camillo and Forlanini Hospitals, Rome, Italy; Inst di Oncologia, Bari, Italy; AUSL Forli, Forli, Italy; Osp San Carlo, Potenza, Italy; Univ of Verona, Verona, Italy
| | - N. Giovannini
- San Camillo and Forlanini Hospitals, Rome, Italy; Inst di Oncologia, Bari, Italy; AUSL Forli, Forli, Italy; Osp San Carlo, Potenza, Italy; Univ of Verona, Verona, Italy
| | - L. Manzione
- San Camillo and Forlanini Hospitals, Rome, Italy; Inst di Oncologia, Bari, Italy; AUSL Forli, Forli, Italy; Osp San Carlo, Potenza, Italy; Univ of Verona, Verona, Italy
| | - E. Donato Di Paola
- San Camillo and Forlanini Hospitals, Rome, Italy; Inst di Oncologia, Bari, Italy; AUSL Forli, Forli, Italy; Osp San Carlo, Potenza, Italy; Univ of Verona, Verona, Italy
| | - S. Alonso
- San Camillo and Forlanini Hospitals, Rome, Italy; Inst di Oncologia, Bari, Italy; AUSL Forli, Forli, Italy; Osp San Carlo, Potenza, Italy; Univ of Verona, Verona, Italy
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Di Costanzo D, Gasperoni S, Dogliotti AL, Frassinetti L, Bruzzi P, Rosso R. Repetita iuvant--INTACC (Intergruppo Italiano Terapia Adiuvante Carcinoma Del Colon). Ann Oncol 2001; 12:1331. [PMID: 11697849 DOI: 10.1023/a:1012201714802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Frassinetti L. [Chemoresistance in antineoplastic treatment of ovarian tumors]. Minerva Ginecol 2001; 53:34-6. [PMID: 11526716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
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