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19 results on '"Maria Ester Puiatti"'

1. THE REVERSED FIELD PINCH

Author

Brett Chapman, J.S. Sarff, Sadao Masamune, James R. Drake, Dominique Escande, Maria Ester Puiatti, Piero Martin, Lionello Marrelli, Escande, Dominique, CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Physique des interactions ioniques et moléculaires (PIIM), and Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear and High Energy Physics, Reversed field pinch, business.industry, Computer science, MHD, magnetic confinement, Magnetic confinement fusion, reversed field pinch, Condensed Matter Physics, 01 natural sciences, Magnetic flux, 010305 fluids & plasmas, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], Control system, [PHYS.PHYS.PHYS-PLASM-PH] Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], 0103 physical sciences, Active feedback, Electricity, High current, Magnetohydrodynamics, Aerospace engineering, 010306 general physics, business
Abstract

This paper reviews the research on the reversed field pinch (RFP) in the last three decades. Substantial experimental and theoretical progress and transformational changes have been achieved since the last review (Bodin 1990 Nucl. Fusion 30 1717–37). The experiments have been performed in devices with different sizes and capabilities. The largest are RFX-mod in Padova (Italy) and MST in Madison (USA). The experimental community includes also EXTRAP-T2R in Sweden, RELAX in Japan and KTX in China. Impressive improvements in the performance are the result of exploration of two lines: the high current operation (up to 2 MA) with the spontaneous occurrence of helical equilibria with good magnetic flux surfaces and the active control of the current profile. A crucial ingredient for the advancements obtained in the experiments has been the development of state-of-art active feedback control systems allowing the control of MHD instabilities in presence of a thin shell. The balance between achievements and still open issues leads us to the conclusion that the RFP can be a valuable and diverse contributor in the quest for fusion electricity.

Published
2020
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2. Design concepts of machine upgrades for the RFX-mod experiment

Author

L. Trevisan, Alessandra Canton, Nicolò Marconato, Marco Valisa, Giuseppe Marchiori, Matteo Agostini, Maria Ester Puiatti, Piergiorgio Sonato, Matteo Vallar, Nisarg Patel, R. Delogu, Piero Agostinetti, Simone Peruzzo, Monica Spolaore, Samuele Dal Bello, Alessandro Fassina, P. Vincenzi, Lionello Marrelli, Roberto Cavazzana, Tommaso Bolzonella, Luca Grando, P. Zanca, Lorella Carraro, M. Siragusa, Gianluca De Masi, Paolo Scarin, A. Zamengo, Mauro Dalla Palma, Paolo Innocente, Paolo Bettini, Marco Bernardi, and Loris Zanotto

Subjects
Tokamak, Computer science, Mechanical engineering, 01 natural sciences, 010305 fluids & plasmas, law.invention, law, Physics::Plasma Physics, 0103 physical sciences, Vacuum sealing, General Materials Science, Ceramic-metal brazing, Fusion devices, RFP configuration, Civil and Structural Engineering, Materials Science (all), Nuclear Energy and Engineering, Mechanical Engineering, 010306 general physics, Resistive touchscreen, Toroid, Reversed field pinch, Upgrade, Magnet, Magnetohydrodynamics, Engineering design process
Abstract

After 10 years of operation since its major modification, an upgrade of the RFX-mod experiment is presently under design. The scientific objective is the improvement of 3D physics studies through a more robust transition to higher confinement regimes in both Reversed Field Pinch (RFP) and Tokamak configuration obtained thanks to an advanced system for the active control of MHD instabilities. The main design driver requirements for this machine upgrade are the removal of the present resistive vacuum vessel and the enhancement of the ‘shell-plasma proximity’, to reduce the deformation of the last close magnetic surface and to improve the self-organized helical plasma regimes. The fulfillment of these requirements implies a major change of the internal components of the machine such as the replacement of the whole first wall, the change of the support system of the stabilizing shell and the modification of the present toroidal support structure to provide the function of vacuum barrier. In combination, other components of the machine will be upgraded, such as magnets and power supply, diagnostic systems and a NBI will be integrated. The paper presents an overview of the engineering design of the new components and highlights the critical aspects of the new torus assembly.

Published
2017
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3. Active MHD control at high currents in RFX-mod

Author

Emilio Martines, Lorella Carraro, A. Pizzimenti, D. Terranova, Paolo Franz, M. Brombin, P. Zaccaria, Rita Lorenzini, V. Antoni, E. Spada, Mario Cavinato, Roberto Cavazzana, S. Cappello, G. Rostagni, F. Milani, Paolo Zanca, L. Apolloni, N. Vianello, Vanni Toigo, L. Zanotto, C. Taliercio, N. Pomaro, Gianluca Spizzo, Giuseppe Zollino, Giuseppe Chitarin, C. Taccon, Barbara Zaniol, Federica Bonomo, A. Murari, A. De Lorenzi, Alessandra Canton, Matteo Zuin, Fulvio Auriemma, L. Garzotti, S. Ortolani, R. Paccagnella, S. C. Guo, Anton Soppelsa, Maria Ester Puiatti, Lionello Marrelli, Tommaso Bolzonella, Gabriele Manduchi, F. Sattin, S. Martini, Alessandro Fassina, G. Malesani, Luca Grando, P. Innocente, Giuseppe Marchiori, P. Piovesan, C. Alessi, D. F. Escande, Roberto Pasqualotto, L. De Pasqual, D. Bonfiglio, M. Valisa, Enrico Zilli, A. Cravotta, Paolo Bettini, A. Masiello, Matteo Agostini, R. Piovan, Diego Marcuzzi, G. Gadani, Piergiorgio Sonato, Alberto Alfier, L. Novello, Simone Peruzzo, Elena Gaio, S. Dal Bello, M. Spolaore, Piero Martin, E. Gazza, Francesco Gnesotto, Adriano Luchetta, Leonardo Giudicotti, P. Scarin, A. Buffa, Marco Gobbin, M. Moresco, G. Serianni, Martini, S, Agostini, M, Alessi, C, Alfier, A, Antoni, V, Apolloni, L, Auriemma, F, Bettini, P, Bolzonella, T, Bonfiglio, D, Bonomo, F, Brombin, M, Buffa, A, Canton, A, Cappello, S, Carraro, L, Cavazzana, R, Cavinato, M, Chitarin, G, Cravotta, A, Dal Bello, S, De Lorenzi, A, De Pasqual, L, Escande, D, Fassina, A, Franz, P, Gadani, G, Gaio, E, Garzotti, L, Gazza, E, Giudicotti, L, Gnesotto, F, Gobbin, M, Grando, L, Guo, S, Innocente, P, Lorenzini, R, Luchetta, A, Malesani, G, Manduchi, G, Marchiori, G, Marcuzzi, D, Marrelli, L, Martin, P, Martines, E, Masiello, A, Milani, F, Moresco, M, Murari, A, Novello, L, Ortolani, S, Paccagnella, R, Pasqualotto, R, Peruzzo, S, Piovan, R, Piovesan, P, Pizzimenti, A, Pomaro, N, Puiatti, M, Rostagni, G, Sattin, F, Scarin, P, Serianni, G, Sonato, P, Spada, E, Soppelsa, A, Spizzo, G, Spolaore, M, Taccon, C, Taliercio, C, Terranova, D, Toigo, V, Valisa, M, Vianello, N, Zaccaria, P, Zanca, P, Zaniol, B, Zanotto, L, Zilli, E, Zollino, G, and Zuin, M

Subjects
Physics, Nuclear and High Energy Physics, RFX-mod, Toroid, business.industry, Pulse duration, reversed field pinch, Plasma, Mechanics, Condensed Matter Physics, MHD control, Amplitude, Optics, Physics::Plasma Physics, RFP, Pinch, Magnetohydrodynamics, business, Voltage, Dynamo
Abstract

The modified RFX is a very flexible device used for a variety of control schemes for MHD instabilities and for advanced reverse field pinch scenarios. Relative to the previous machine, RFX-mod has a thin Cu shell with vertical field penetration time τS, lowered from 450 to 50 ms and shell/plasma proximity from b/a ≤ 1.24-1.1. Toroidal equilibrium is feedback-controlled and new power supplies provide better Bφ control. Newly designed graphite tiles protect the vessel from localized power deposition. A mesh of 192 external saddle coils, supervised by a digital feedback system, controls radial fields due to field errors and MHD modes. The paper presents an overview of the very encouraging results obtained using both new and 'standard' advanced operational modes in the current range 0.3-1 MA. A dramatic improvement of plasma performance was obtained by using the saddle coils to cancel all the radial field components, an operation mode dubbed virtual shell (VS). The toroidal voltage was lowered by more than 25% and the pulse length was tripled, up to 7 times the τS. Steady-state RFP pulses are now limited only by the applied volt-seconds. The improved magnetic boundary also has an effect on the tearing modes underlying the sustainment of the RFP, whose core amplitude is more than halved. The VS combined with new schemes for the active rotation of the MHD dynamo modes has allowed us to obtain reliable and well-controlled long RFP pulses in the MA current range. This results in a 100% increase in the particle and energy confinement time relative to the previous experiment and opens the possibility of exploring the machine performance in the 2 MA design range. © 2007 IAEA.

Published
2007
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4. Experimental and simulated VUV spectra from the JET tokamak and the reversed field pinch RFX

Author

Maria Ester Puiatti, M. G. O'Mullane, M. Valisa, Paolo Scarin, Fabio Sattin, Lorella Carraro, K. B. Fournier, I. H. Coffey, and M. Mattioli

Subjects
Physics, Jet (fluid), atomic physics, Tokamak, Reversed field pinch, Spectrometer, Magnetic confinement fusion, Plasma, Condensed Matter Physics, Spectral line, law.invention, Nuclear Energy and Engineering, law, Ionization, Controlled thermonuclear fusion, plasma physics, impurity modelling, Atomic physics, impurities emission spectra
Abstract

Experimental VUV spectra from the JET tokamak and from the reversed field pinch RFX have been simulated. For the former device both n = 2 to n = 2 L-shell Ar and Ne spectra (respectively, in the 14.5-43.0 and in the 35.0-80.0 nm ranges) were considered, whereas for RFX only the Ne spectrum was available. The spectra have been observed with the SPRED spectrometer. From the simulation of the spectra, relative sensitivity curves have been obtained for each instrument in the ranges of the simulation. For RFX only, it has been possible to extend this curve from ~13.0 to ~105 nm, by simulating intrinsic C and O emissions. The photon emission coefficients of the lines with wavelengths in the ranges of the experimental spectra were obtained from collisional-radiative models. For Ar and Ne these coefficients have been calculated by the Hebrew University Lawrence Livermore Atomic Codes atomic physics codes, whereas for C and O the corresponding coefficients have been taken from the `Atomic Data and Analysis Structure' database. Impurity modelling is performed using a one-dimensional impurity transport code, calculating for each atomic species the radial distribution of the impurity ions. The line brightnesses are evaluated in a post-processing subroutine and the simulations of the spectra are obtained. The spectral simulations (including impurity ion transport) give confidence in the atomic physics calculations, and allow the determination of the transport coefficients in the plasma regions from which the considered ionization states emit. Finally, the obtained relative sensitivity curves of the two SPRED spectrometers have been compared with the calibrations performed by means of the branching ratio technique.

Published
2001
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5. Wall conditioning and density control in the reversed field pinch RFX-mod

Author

S. Dal Bello, Paolo Scarin, David Terranova, Lorella Carraro, Lane Roquemore, Alessandro Fassina, Gianluca Spizzo, Fulvio Auriemma, Maria Ester Puiatti, Matteo Agostini, Paolo Innocente, Stefano Munaretto, Italo Predebon, Roberto Cavazzana, Paolo Franz, Luca Grando, G. Mazzitelli, D.K. Mansfield, M. Gobbin, Alessandra Canton, A.V. Vertkov, G. De Masi, Barbara Zaniol, M. Valisa, Lionello Marrelli, Piero Martin, A. Ruzzon, and Mazzitelli, G.

Subjects
Nuclear and High Energy Physics, Glow discharge, Materials science, Hydrogen, Reversed field pinch, magnetic confinement, Evaporation, chemistry.chemical_element, reversed field pinch, Injector, Plasma, Condensed Matter Physics, law.invention, THERMONUCLEAR REACTIONS, chemistry, law, TOKAMAK, Lithium, Atomic physics, RFX, Helium
Abstract

In the reversed field pinch RFX-mod at the highest plasma current of 2 MA, when error fields are not effectively feedback controlled, localized thermal loads up to tens of MW m-2 can be produced. The graphite tiles withstand such high power loads, but the high hydrogen retention makes density control extremely difficult. Several wall conditioning techniques have been optimized in the last campaigns, including helium glow discharge cleaning and wall boronization by diborane glow discharges. More recently, lithium conditioning has been applied for the first time in a reversed field pinch by the evaporation technique. The main results are discussed in this paper. Lithization leads to important operational advantages: a significant improvement of the density control is obtained. Densities up to n/nG ≈ 0.5 can be produced in a controlled way. At the same value of input power, plasmas at higher densities can be sustained. However, due to the short particle confinement time, such densities are reached with high rates of gas puffing and the resulting profiles at high density are edge peaked. A lithium multipellet injector, to be applied in order to obtain a more uniform deposition, has been tested. © 2013 IAEA, Vienna.

Published
2013
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6. Overview of the RFX fusion science program

Author

M. Gobbin, Roberto Pasqualotto, D. Bonfiglio, Enrico Zilli, Giuseppe Marchiori, Piero Martin, S. Martini, Fulvio Auriemma, E. Gazza, D.K. Mansfield, P. Zaccaria, Piergiorgio Sonato, S. Ortolani, Wolf-Dieter Schneider, D. Yadikin, Stefano Munaretto, L. Piron, M. Valisa, Fabio Sattin, Susanna Cappello, G. V. Perverezev, F. Milani, Roberto Paccagnella, Paolo Bettini, S. Fiameni, Roscoe White, A. Ruzzon, V. Antoni, Leonardo Giudicotti, Yueqiang Liu, Lionello Marrelli, Nicola Vianello, S. Dal Bello, A. Scaggion, V. Rigato, Fabio Villone, A. Zamengo, Federica Bonomo, R. Cavazzana, M. Baruzzo, L. Carraro, F. Fantini, Giuseppe Zollino, Barbara Zaniol, Rita Lorenzini, Luis Chacon, X. Garbet, C. Angioni, Andrea Rizzolo, G. De Masi, G. Rostagni, W. A. Cooper, Manabu Takechi, Piero Agostinetti, Paolo Scarin, A. Pizzimenti, Yongkyoon In, Sheena Menmuir, Silvia Spagnolo, M. Moresco, Satoru Kiyama, S. P. Hirshman, M. Okabayashi, Giuseppe Chitarin, S. C. Guo, Gabriele Manduchi, Dominique Escande, Gianluigi Serianni, Alessandro Fassina, Luca Grando, Simona Barison, Allen H. Boozer, Michael Drevlak, Diego Marcuzzi, M. Pavei, J.Q. Dong, Anton Soppelsa, B. Momo, Gianluca Spizzo, Hajime Sakakita, Neil Pomphrey, Shunsuke Ide, Donald A. Spong, J. S. Sarff, Alessandra Canton, D. Lopez Bruna, M. Brombin, Matteo Zuin, T. Bolzonella, R. Piovan, Songfen Liu, Alberto Ferro, Italo Predebon, V. Igochine, L. Zanotto, Simone Peruzzo, Elena Gaio, P. Piovesan, Cesare Taliercio, J. Adamek, Go Matsunaga, P. Zanca, A. Buffa, M. Veranda, N. Pomaro, M. Spolaore, Oliviero Barana, Francesco Gnesotto, Emilio Martines, M. Dalla Palma, Paolo Franz, David Terranova, Yoichi Hirano, Matteo Agostini, G. Mazzitelli, Alberto Alfier, L. Novello, Vanni Toigo, M. Boldrin, R. Delogu, Guglielmo Rubinacci, Maria Ester Puiatti, A. Fiorentin, Karsten McCollam, E. Spada, M. Cavinato, A. De Lorenzi, L. Apolloni, J. Brotankova, F. Fellin, P. Innocente, Raul Sanchez, Zhirui Wang, Adriano Luchetta, Martin, P, Adamek, J, Agostinetti, P, Agostini, M, Alfier, A, Angioni, C, Antoni, V, Apolloni, L, Auriemma, F, Barana, O, Barison, S, Baruzzo, M, Bettini, P, Boldrin, M, Bolzonella, T, Bonfiglio, D, Bonomo, F, Boozer, A, Brombin, M, Brotankova, J, Buffa, A, Canton, A, Cappello, S, Carraro, L, Cavazzana, R, Cavinato, M, Chacon, L, Chitarin, G, Cooper, W, Dal Bello, S, Dalla Palma, M, Delogu, R, De Lorenzi, A, De Masi, G, Dong, J, Drevlak, M, Escande, D, Fantini, F, Fassina, A, Fellin, F, Ferro, A, Fiameni, S, Fiorentin, A, Franz, P, Gaio, E, Garbet, X, Gazza, E, Giudicotti, L, Gnesotto, F, Gobbin, M, Grando, L, Guo, S, Hirano, Y, Hirshman, S, Ide, S, Igochine, V, In, Y, Innocente, P, Kiyama, S, Liu, S, Liu, Y, Bruna, D, Lorenzini, R, Luchetta, A, Manduchi, G, Mansfield, D, Marchiori, G, Marcuzzi, D, Marrelli, L, Martini, S, Matsunaga, G, Martines, E, Mazzitelli, G, Mccollam, K, Menmuir, S, Milani, F, Momo, B, Moresco, M, Munaretto, S, Novello, L, Okabayashi, M, Ortolani, S, Paccagnella, R, Pasqualotto, R, Pavei, M, Perverezev, G, Peruzzo, S, Piovan, R, Piovesan, P, Piron, L, Pizzimenti, A, Pomaro, N, Pomphrey, N, Predebon, I, Puiatti, M, Rigato, V, Rizzolo, A, Rostagni, G, Rubinacci, G, Ruzzon, A, Sakakita, H, Sanchez, R, Sarff, J, Sattin, F, Scaggion, A, Scarin, P, Schneider, W, Serianni, G, Sonato, P, Spada, E, Soppelsa, A, Spagnolo, S, Spolaore, M, Spong, D, Spizzo, G, Takechi, M, Taliercio, C, Terranova, D, Toigo, V, Valisa, M, Veranda, M, Vianello, N, Villone, F, Wang, Z, White, R, Yadikin, D, Zaccaria, P, Zamengo, A, Zanca, P, Zaniol, B, Zanotto, L, Zilli, E, Zollino, G, Zuin, M, Martin, P., Adamek, J., Agostinetti, P., Agostini, M., Alfier, A., Angioni, C., Antoni, V., Apolloni, L., Auriemma, F., Barana, O., Barison, S., Baruzzo, M., Bettini, P., Boldrin, M., Bolzonella, T., Bonfiglio, D., Bonomo, F., Boozer, A. H., Brombin, M., Brotankova, J., Buffa, A., Canton, A., Cappello, S., Carraro, L., Cavazzana, R., Cavinato, M., Chacon, L., Chitarin, G., Cooper, W. A., Bello, S. D., Palma, M. D., Delogu, R., Lorenzi, A. D., Masi, G. D., Dong, J. Q., Drevlak, M., Escande, D. F., Fantini, F., Fassina, A., Fellin, F., Ferro, A., Fiameni, S., Fiorentin, A., Franz, P., Gaio, E., Garbet, X., Gazza, E., Giudicotti, L., Gnesotto, F., Gobbin, M., Grando, L., Guo, S. C., Hirano, Y., Hirshman, S. P., Ide, S., Igochine, V., In, Y., Innocente, P., Kiyama, S., Liu, S. F., Liu, Y. Q., Bruna, D. L., Lorenzini, R., Luchetta, A., Manduchi, G., Mansfield, D. K., Marchiori, G., Marcuzzi, D., Marrelli, L., Martini, S., Matsunaga, G., Martines, E., Mazzitelli, G., Mccollam, K., Menmuir, S., Milani, F., Momo, B., Moresco, M., Munaretto, S., Novello, L., Okabayashi, M., Ortolani, S., Paccagnella, R., Pasqualotto, R., Pavei, M., Perverezev, G. V., Peruzzo, S., Piovan, R., Piovesan, P., Piron, L., Pizzimenti, A., Pomaro, N., Pomphrey, N., Predebon, I., Puiatti, M. E., Rigato, V., Rizzolo, A., Rostagni, G., Rubinacci, Guglielmo, Ruzzon, A., Sakakita, H., Sanchez, R., Sarff, J. S., Sattin, F., Scaggion, A., Scarin, P., Schneider, W., Serianni, G., Sonato, P., Spada, E., Soppelsa, A., Spagnolo, S., Spolaore, M., Spong, D. A., Spizzo, G., Takechi, M., Taliercio, C., Terranova, D., Toigo, V., Valisa, M., Veranda, M., Vianello, N., Villone, F., Wang, Z., White, R. B., Yadikin, D., Zaccaria, P., Zamengo, A., Zanca, P., Zaniol, B., Zanotto, L., Zilli, E., Zollino, G., and Zuin, M.

Subjects
Nuclear and High Energy Physics, RFX-mod, Tokamak, Nuclear engineering, PLASMAS, CONFINEMENT, reversed field pinch, magnetic confinement, law.invention, law, Physics::Plasma Physics, RFP, Scaling, Mod, Physics, Reversed field pinch, STABILITY, Magnetic confinement fusion, INTERNAL TRANSPORT BARRIER, Plasma, Fusion power, Condensed Matter Physics, REVERSED-FIELD-PINCH, Atomic physics, Magnetohydrodynamics, Stellarator
Abstract

This paper summarizes the main achievements of the RFX fusion science program in the period between the 2008 and 2010 IAEA Fusion Energy Conferences. RFX-mod is the largest reversed field pinch in the world, equipped with a system of 192 coils for active control of MHD stability. The discovery and understanding of helical states with electron internal transport barriers and core electron temperature >1.5 keV significantly advances the perspectives of the configuration. Optimized experiments with plasma current up to 1.8 MA have been realized, confirming positive scaling. The first evidence of edge transport barriers is presented. Progress has been made also in the control of first-wall properties and of density profiles, with initial first-wall lithization experiments. Micro-turbulence mechanisms such as ion temperature gradient and micro-tearing are discussed in the framework of understanding gradient-driven transport in low magnetic chaos helical regimes. Both tearing mode and resistive wall mode active control have been optimized and experimental data have been used to benchmark numerical codes. The RFX programme also provides important results for the fusion community and in particular for tokamaks and stellarators on feedback control of MHD stability and on three-dimensional physics. On the latter topic, the result of the application of stellarator codes to describe three-dimensional reversed field pinch physics will be presented. © 2011 IAEA, Vienna.

Published
2011
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7. Confinement studies on RFX

Author

Paolo Scarin, P. Zaccaria, S. Costa, P. Kusstatscher, Piero Martin, Roberto Paccagnella, Piergiorgio Sonato, Giuseppe Chitarin, Pietro Fiorentin, G. Malesani, Enrico Zilli, G. Rostagni, P. O'Leary, Lorella Carraro, S. Martini, M. Bassan, Giuseppe Zollino, Vanni Toigo, Andrea Murari, S. Vitturi, Francesco Trevisan, Maria Ester Puiatti, Andrea Stella, Gabriele Manduchi, M. Moresco, Mario Bagatin, Gianluigi Serianni, Leonardo Giudicotti, A. Buffa, Paolo Innocente, E. Spada, L. Benfatto, Giuseppe Marchiori, R. Guatieri, Emilio Martines, E. Casarotto, Elena Gaio, M. Fauri, A. Sardella, F. Bellina, H. Bergsåker, V. Schmidt, W. Baker, L. Apolloni, P. Collarin, V. Antoni, R. Piovan, M. Valisa, P. Campostrini, O. Hemming, Adriano Luchetta, Roberto Pasqualotto, N. Pomaro, Susanna Cappello, Francesco Gnesotto, Daniele Desideri, A. De Lorenzi, Massimo Guarnieri, C. Ferrer, L. Tramontin, Alvise Maschio, Antoni, V, Apolloni, L, Bagatin, M, Baker, W, Bassan, M, Bellina, F, Benfatto, I, Bergsaker, H, Buffa, A, Campostrini, P, Cappello, S, Carraro, L, Casarotto, E, Chitarin, G, Collarin, P, Costa, S, Delorenzi, A, Desideri, D, Fauri, M, Ferrer, C, Fiorentin, P, Gaio, E, Giudicotti, L, Gnesotto, F, Guarnieri, M, Guatieri, R, Hemming, O, Innocente, P, Kusstatscher, P, Luchetta, A, Malesani, G, Manduchi, G, Marchiori, G, Martin, P, Martines, E, Martini, S, Maschio, A, Moresco, M, Murari, A, Oleary, P, Paccagnella, R, Pasqualotto, R, Piovan, R, Pomaro, N, Puiatti, M, Rostagni, G, Sardella, A, Scarin, P, Schmidt, V, Serianni, G, Sonato, P, Spada, E, Stella, A, Toigo, V, Tramontin, L, Trevisan, F, Valisa, M, Vitturi, S, Zaccaria, P, Zilli, E, and Zollino, G

Subjects
Electron density, Materials science, Nuclear Energy and Engineering, Impurity, Beta (plasma physics), RFP, Ion temperature, reversed field pinch, Electron, Atomic physics, Condensed Matter Physics, RFX, Plasma current
Abstract

The results of the first year of operation of the experiment RFX are reported. Profiles of electron density, electron and ion temperature and impurity emission have been measured at plasma current I

Published
1993
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8. Overview of RFX-mod results

Author

R. Paccagnella, Cesare Taliercio, J. Adamek, V. Antoni, A. Pizzimenti, Gianluca Spizzo, Gabriele Manduchi, E. Spada, Vanni Toigo, D. Terranova, Alberto Ferro, N. Pomaro, P. Zaccaria, Rita Lorenzini, B. E. Chapman, Piero Martin, L. Guazzotto, A. Zamengo, Simone Peruzzo, Elena Gaio, Italo Predebon, V. Igochine, F. Milani, M. Spolaore, Oliviero Barana, Francesco Gnesotto, Alessandro Fassina, Giuseppe Marchiori, E. Gazza, G. Serianni, L. Zanotto, Piergiorgio Sonato, L. Piron, A. De Lorenzi, Diego Marcuzzi, Alessandra Canton, Matteo Zuin, T. Bolzonella, Federica Bonomo, Fabio Villone, M. Valisa, S. Cappello, H. Zohm, R. Cavazzana, J. Brotankova, Maria Ester Puiatti, M. Gobbin, P. Scarin, P. Zanca, Silvia Spagnolo, M. Baruzzo, Lionello Marrelli, Fabio Sattin, A. Buffa, Nicola Vianello, Fulvio Auriemma, Karsten McCollam, S. Ortolani, J. S. Sarff, S. Dal Bello, M. Cavinato, Paolo Bettini, P. Piovesan, G. Rostagni, P. Innocente, P. Buratti, M. Moresco, Roscoe White, Leonardo Giudicotti, Anton Soppelsa, Guglielmo Rubinacci, Sheena Menmuir, Emilio Martines, Paolo Franz, L. Carraro, D. Bonfiglio, Enrico Zilli, S. Martini, G. De Masi, L. Apolloni, Giuseppe Chitarin, M. Brombin, R. Piovan, Matteo Agostini, J.A. Reusch, Barbara Zaniol, Yueqiang Liu, S. C. Guo, Dominique Escande, S.V. Annibaldi, Alberto Alfier, L. Novello, Luca Grando, Adriano Luchetta, Roberto Pasqualotto, D. Yadikin, Martin, P, Apolloni, L, Puiatti, M, Adamek, J, Agostini, M, Alfier, A, Annibaldi, S, Antoni, V, Auriemma, F, Barana, O, Baruzzo, M, Bettini, P, Bolzonella, T, Bonfiglio, D, Bonomo, F, Brombin, M, Brotankova, J, Buffa, A, Buratti, P, Canton, A, Cappello, S, Carraro, L, Cavazzana, R, Cavinato, M, Chapman, B, Chitarin, G, Dal Bello, S, De Lorenzi, A, De Masi, G, Escande, D, Fassina, A, Ferro, A, Franz, P, Gaio, E, Gazza, E, Giudicotti, L, Gnesotto, F, Gobbin, M, Grando, L, Guazzotto, L, Guo, S, Igochine, V, Innocente, P, Liu, Y, Lorenzini, R, Luchetta, A, Manduchi, G, Marchiori, G, Marcuzzi, D, Marrelli, L, Martini, S, Martines, E, Mccollam, K, Menmuir, S, Milani, F, Moresco, M, Novello, L, Ortolani, S, Paccagnella, R, Pasqualotto, R, Peruzzo, S, Piovan, R, Piovesan, P, Piron, L, Pizzimenti, A, Pomaro, N, Predebon, I, Reusch, J, Rostagni, G, Rubinacci, G, Sarff, J, Sattin, F, Scarin, P, Serianni, G, Sonato, P, Spada, E, Soppelsa, A, Spagnolo, S, Spolaore, M, Spizzo, G, Taliercio, C, Terranova, D, Toigo, V, Valisa, M, Vianello, N, Villone, F, White, R, Yadikin, D, Zaccaria, P, Zamengo, A, Zanca, P, Zaniol, B, Zanotto, L, Zilli, E, Zohm, H, Zuin, M, Martin, P., Apolloni, L., Puiatti, M. E., Adamek, J., Agostini, M., Alfier, A., Annibaldi, S. V., Antoni, V., Auriemma, F., Barana, O., Baruzzo, M., Bettini, P., Bolzonella, T., Bonfiglio, D., Bonomo, F., Brombin, M., Brotankova, J., Buffa, A., Buratti, P., Canton, A., Cappello, S., Carraro, L., Cavazzana, R., Cavinato, M., Chapman, B. E., Chitarin, G., Dal Bello, S., De Lorenzi, A., De Masi, G., Escande, D. F., Fassina, A., Ferro, A., Franz, P., Gaio, E., Gazza, E., Giudicotti, L., Gnesotto, F., Gobbin, M., Grando, L., Guazzotto, L., Guo, S. C., Igochine, V., Innocente, P., Liu, Y. Q., Lorenzini, R., Luchetta, A., Manduchi, G., Marchiori, G., Marcuzzi, D., Marrelli, L., Martini, S., Martines, E., Mccollam, K., Menmuir, S., Milani, F., Moresco, M., Novello, L., Ortolani, S., Paccagnella, R., Pasqualotto, R., Peruzzo, S., Piovan, R., Piovesan, P., Piron, L., Pizzimenti, A., Pomaro, N., Predebon, I., Reusch, J. A., Rostagni, G., Rubinacci, Guglielmo, Sarff, J. S., Sattin, F., Scarin, P., Serianni, G., Sonato, P., Spada, E., Soppelsa, A., Spagnolo, S., Spolaore, M., Spizzo, G., Taliercio, C., Terranova, D., Toigo, V., Valisa, M., Vianello, N., Villone, F., White, R. B., Yadikin, D., Zaccaria, P., Zamengo, A., Zanca, P., Zaniol, B., Zanotto, L., Zilli, E., Zohm, H., and Zuin, M.

Subjects
Physics, Nuclear and High Energy Physics, Leading edge, Tokamak, RFX-mod, Reversed field pinch, MHD, magnetic confinement, Magnetic confinement fusion, reversed field pinch, Fusion power, Condensed Matter Physics, TRANSPORT, law.invention, LUNDQUIST NUMBER, Nuclear physics, REVERSED-FIELD-PINCH, EDGE, law, RFP, Electron temperature, Magnetohydrodynamics, Plasma stability
Abstract

With the exploration of the MA plasma current regime in up to 0.5 s long discharges, RFX-mod has opened new and very promising perspectives for the reversed field pinch (RFP) magnetic configuration, and has made significant progress in understanding and improving confinement and in controlling plasma stability. A big leap with respect to previous knowledge and expectations on RFP physics and performance has been made by RFX-mod since the last 2006 IAEA Fusion Energy Conference. A new self-organized helical equilibrium has been experimentally achieved (the Single Helical Axis - SHAx - state), which is the preferred state at high current. Strong core electron transport barriers characterize this regime, with electron temperature gradients comparable to those achieved in tokamaks, and by a factor of 4 improvement in confinement time with respect to the standard RFP. RFX-mod is also providing leading edge results on real-time feedback control of MHD instabilities, of general interest for the fusion community. © 2009 IAEA, Vienna.

Published
2009
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9. Helical equilibria and magnetic structures in the reversed field pinch and analogies to the tokamak and stellarator

Author

Stefano Munaretto, L. Carraro, Alessandra Canton, S. Dal Bello, Matteo Zuin, A. Pizzimenti, D. Bonfiglio, S. Martini, V. Antoni, Elena Gaio, Fulvio Auriemma, Lionello Marrelli, Fabio Sattin, B. Momo, Tommaso Bolzonella, Nicola Vianello, L. Apolloni, Emilio Martines, Gianluca Spizzo, M. Baruzzo, R. Delogu, Paolo Franz, Susanna Cappello, P. Piovesan, Italo Predebon, M. Moresco, Rita Lorenzini, Leonardo Giudicotti, L. Novello, Sheena Menmuir, Paolo Scarin, P. Zanca, Anton Soppelsa, Luca Grando, G. De Masi, M. Spolaore, Giuseppe Marchiori, Roberto Pasqualotto, Neil Pomphrey, S. C. Guo, David Terranova, A. Zamengo, P. Innocente, Maria Ester Puiatti, Piero Martin, E. Gazza, Dominique Escande, Alberto Alfier, Allen H. Boozer, M. Valisa, L. Piron, Matteo Agostini, Barbara Zaniol, M. Brombin, R. Piovan, L. Zanotto, E. Spada, Gabriele Manduchi, Gianluigi Serianni, Alessandro Fassina, Roberto Paccagnella, Federica Bonomo, R. Cavazzana, Silvia Spagnolo, Cesare Taliercio, M. Gobbin, Puiatti, M, Alfier, A, Auriemma, F, Cappello, S, Carraro, L, Cavazzana, R, Dal Bello, S, Fassina, A, Escande, D, Franz, P, Gobbin, M, Innocente, P, Lorenzini, R, Marrelli, L, Martin, P, Piovesan, P, Predebon, I, Sattin, F, Spizzo, G, Terranova, D, Valisa, M, Zaniol, B, Zanotto, L, Zuin, M, Agostini, M, Antoni, V, Apolloni, L, Baruzzo, M, Bolzonella, T, Bonfiglio, D, Bonomo, F, Boozer, A, Brombin, M, Canton, A, Delogu, R, De Masi, G, Gaio, E, Gazza, E, Giudicotti, L, Grando, L, Guo, S, Manduchi, G, Marchiori, G, Martines, E, Martini, S, Menmuir, S, Momo, B, Moresco, M, Munaretto, S, Novello, L, Paccagnella, R, Pasqualotto, R, Piovan, R, Piron, L, Pizzimenti, A, Pomphrey, N, Scarin, P, Serianni, G, Spada, E, Soppelsa, A, Spagnolo, S, Spolaore, M, Taliercio, C, Vianello, N, Zamengo, A, and Zanca, P

Subjects
Physics, Tokamak, RFX-mod, Reversed field pinch, Field (physics), Condensed matter physics, Magnetic confinement fusion, reversed field pinch, Edge (geometry), SELF-ORGANIZATION, Condensed Matter Physics, law.invention, Core (optical fiber), quasi-single helicity, INTERNAL TRANSPORT BARRIERS, MHD ACTIVE CONTROL, Nuclear Energy and Engineering, law, RFP, QSH, plasma equilibrium, Atomic physics, Pressure gradient, Stellarator
Abstract

The reversed field pinch configuration is characterized by the presence of magnetic structures both in the core and at the edge: in the core, at high plasma current the spontaneous development of a helical structure is accompanied by the appearance of internal electron transport barriers; at the edge strong pressure gradients, identifying an edge transport barrier, are observed too, related to the position of the field reversal surface. The aim of this paper is the experimental characterization of both the internal and edge transport barriers in relation to the magnetic topology, discussing possible analogies and differences with other confinement schemes. © 2009 IOP Publishing Ltd.

Published
2009
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10. High current regimes in RFX-mod

Author

Cesare Taliercio, V. Antoni, Gabriele Manduchi, Fulvio Auriemma, Alberto Alfier, S. Dal Bello, L. Apolloni, L. Carraro, Gianluigi Serianni, S. Ortolani, Fabio Sattin, D. Marcuzzi, M. Baruzzo, Alessandro Fassina, Giuseppe Chitarin, Paolo Bettini, P. Innocente, M. Spolaore, Oliviero Barana, Alessandra Canton, N. Pomaro, Matteo Zuin, Francesco Gnesotto, D. Bonfiglio, Enrico Zilli, G. Rostagni, S. Martini, Piergiorgio Sonato, V. Toigo, David Terranova, Gianluca Spizzo, F. Milani, Anton Soppelsa, A. De Lorenzi, M. Gobbin, M. Moresco, Roberto Paccagnella, Italo Predebon, D. Yadikin, Piero Martin, L. Guazzotto, E. Gazza, Matteo Agostini, Federica Bonomo, Lionello Marrelli, Tommaso Bolzonella, Nicola Vianello, P. Zanca, R. Cavazzana, A. Buffa, Emilio Martines, Rita Lorenzini, Leonardo Giudicotti, M. Brombin, Silvia Spagnolo, Paolo Franz, Paolo Scarin, P. Buratti, Giuseppe Marchiori, R. Piovan, L. Zanotto, P. Piovesan, M. Valisa, Maria Ester Puiatti, Simone Peruzzo, Elena Gaio, V. Igochine, Karsten McCollam, E. Spada, M. Cavinato, Susanna Cappello, G. De Masi, Andrea Pizzimenti, S. C. Guo, Dominique Escande, Luca Grando, Barbara Zaniol, P. Zaccaria, Adriano Luchetta, Roberto Pasqualotto, L. Novello, J. S. Sarff, L. Piron, Valisa, M, Bolzonella, T, Buratti, P, Carraro, L, Cavazzana, R, Dal Bello, S, Martin, P, Pasqualotto, R, Sarff, J, Spolaore, M, Zanca, P, Zanotto, L, Agostini, M, Alfier, A, Antoni, V, Apolloni, L, Auriemma, F, Barana, O, Baruzzo, M, Bettini, P, Bonfiglio, D, Bonomo, F, Brombin, M, Buffa, A, Canton, A, Cappello, S, Cavinato, M, Chitarin, G, De Lorenzi, A, De Masi, G, Escande, D, Fassina, A, Franz, P, Gaio, E, Gazza, E, Giudicotti, L, Gnesotto, F, Gobbin, M, Grando, L, Guazzotto, L, Guo, S, Igochine, V, Innocente, P, Lorenzini, R, Luchetta, A, Manduchi, G, Marchiori, G, Marcuzzi, D, Marrelli, L, Martini, S, Martines, E, Mccollam, K, Milani, F, Moresco, M, Novello, L, Ortolani, S, Paccagnella, R, Peruzzo, S, Piovan, R, Piron, L, Pizzimenti, A, Piovesan, P, Pomaro, N, Predebon, I, Puiatti, M, Rostagni, G, Sattin, F, Scarin, P, Serianni, G, Sonato, P, Spada, E, Soppelsa, A, Spagnolo, S, Spizzo, G, Taliercio, C, Terranova, D, Toigo, V, Vianello, N, Yadikin, D, Zaccaria, P, Zaniol, B, Zilli, E, and Zuin, M

Subjects
Physics, plasma confinement, RFX-mod, Reversed field pinch, Condensed matter physics, reversed field pinch, Torus, Plasma, Electron, Condensed Matter Physics, Symmetry (physics), quasi-single helicity, Nuclear Energy and Engineering, Physics::Plasma Physics, RFP, Electron temperature, QSH, Magnetohydrodynamic drive, Current (fluid)
Abstract

Optimization of machine operation, including plasma position control, density control and especially feedback control on multiple magnetohydrodynamic modes, has led RFX-mod to operate reliably at 1.5 MA, the highest current ever achieved on a reversed field pinch (RFP). At high current and low density the magnetic topology spontaneously self-organizes in an Ohmical helical symmetry, with the new magnetic axis helically twisting around the geometrical axis of the torus. The separatrix of the island disappears leaving a wide and symmetric thermal structure with large gradients in the electron temperature profile. The new topology still displays an intermittent nature but its overall presence has reached 85% of the current flat-top period. The large gradients in the electron temperature profile appear to be marginal for the destabilization of ion temperature gradient modes on the assumption that ions and electrons have the same gradients. There are indications that higher currents could provide the conditions under which to prove the existence of a true helical equilibrium as the standard RFP configuration. © 2008 IOP Publishing Ltd.

Published
2008
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11. Magnetic self organization, MHD active control and confinement in RFX-mod

Author

Paolo Zanca, Piero Martin, A. De Lorenzi, E. Gazza, F. Milani, S. Dal Bello, Lionello Marrelli, F. Sattin, Leonardo Giudicotti, Giuseppe Marchiori, N. Vianello, Matteo Agostini, R. Piovan, Fulvio Auriemma, A. Masiello, S. Ortolani, Vanni Toigo, M. Brombin, P. Innocente, G. Gadani, G. Rostagni, Alberto Alfier, L. Novello, M. Moresco, Giuseppe Chitarin, Italo Predebon, Anton Soppelsa, M. Valisa, D. F. Escande, Paolo Bettini, Mario Cavinato, L. Apolloni, S. C. Guo, Andrea Murari, C. Alessi, Roberto Pasqualotto, Maria Ester Puiatti, C. Taccon, R. Paccagnella, Piergiorgio Sonato, D. Bonfiglio, Simone Peruzzo, Diego Marcuzzi, Emilio Martines, Federica Bonomo, Paolo Franz, Barbara Zaniol, Elena Gaio, Enrico Zilli, S. Martini, C. Taliercio, Gianluca Spizzo, S. Cappello, V. Antoni, Gabriele Manduchi, Alessandro Fassina, L. Zanotto, P. Piovesan, Alessandra Canton, Matteo Zuin, L. Carraro, T. Bolzonella, Luca Grando, G. Malesani, A. Pizzimenti, D. Terranova, Rita Lorenzini, E. Spada, G. Serianni, Marco Gobbin, P. Zaccaria, Giuseppe Zollino, Roberto Cavazzana, Adriano Luchetta, P. Scarin, A. Buffa, M. Spolaore, Oliviero Barana, Francesco Gnesotto, N. Pomaro, Marrelli, L, Zanca, P, Valisa, M, Marchiori, G, Alfier, A, Bonomo, F, Gobbin, M, Piovesan, P, Terranova, D, Agostini, M, Alessi, C, Antoni, V, Apolloni, L, Auriemma, F, Barana, O, Bettini, P, Bolzonella, T, Bonfiglio, D, Brombin, M, Buffa, A, Canton, A, Cappello, S, Carraro, L, Cavazzana, R, Cavinato, M, Chitarin, G, Dal Bello, S, De Lorenzi, A, Escande, D, Fassina, A, Franz, P, Gadani, G, Gaio, E, Gazza, E, Giudicotti, L, Gnesotto, F, Grando, L, Guo, S, Innocente, P, Lorenzini, R, Luchetta, A, Malesani, G, Manduchi, G, Marcuzzi, D, Martin, P, Martini, S, Martines, E, Masiello, A, Milani, F, Moresco, M, Murari, A, Novello, L, Ortolani, S, Paccagnella, R, Pasqualotto, R, Peruzzo, S, Piovan, R, Pizzimenti, A, Pomaro, N, Predebon, I, Puiatti, M, Rostagni, G, Sattin, F, Scarin, P, Serianni, G, Sonato, P, Spada, E, Soppelsa, A, Spizzo, G, Spolaore, M, Taccon, C, Taliercio, C, Toigo, V, Vianello, N, Zaccaria, P, Zaniol, B, Zanotto, L, Zilli, E, Zollino, G, and Zuin, M

Subjects
Physics, REVERSED-FIELD PINCHES, RFX-mod, Reversed field pinch, Sideband, active control, Rotational symmetry, Boundary (topology), INTELLIGENT SHELL, reversed field pinch, Condensed Matter Physics, Magnetic field, BOUNDARY, Nuclear Energy and Engineering, Physics::Plasma Physics, Quantum electrodynamics, Harmonics, RFP, RECONSTRUCTION, Magnetohydrodynamics, PLASMA-WALL INTERACTIONS, RESISTIVE WALL, Saddle
Abstract

RFX-mod is a reversed field pinch (RFP) experiment equipped with a system that actively controls the magnetic boundary. In this paper we describe the results of a new control algorithm, the clean mode control (CMC), in which the aliasing of the sideband harmonics generated by the discrete saddle coils is corrected in real time. CMC operation leads to a smoother (i.e. more axisymmetric) boundary. Tearing modes rotate (up to 100 Hz) and partially unlock. Plasma-wall interaction diminishes due to a decrease of the non-axisymmetric shift of the plasma column. With the ameliorated boundary control, plasma current has been successfully increased to 1.5 MA, the highest for an RFP. In such regimes, the magnetic dynamics is dominated by the innermost resonant mode, the internal magnetic field gets close to a pure helix and confinement improves. © 2007 IOP Publishing Ltd.

Published
2007
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12. Analysis and modelling of the magnetic and plasma profiles during PPCD experiments in RFX

Author

Gianluca Spizzo, Paolo Innocente, A. De Lorenzi, G. Malesani, V. Antoni, C. Taliercio, S. C. Guo, Pietro Fiorentin, R. Paccagnella, G. Telesca, Lorella Carraro, Enrico Zilli, S. Martini, B. Pégourié, Giuseppe Marchiori, Maria Ester Puiatti, P. Piovesan, Simone Peruzzo, F. Milani, L. Zanotto, Paolo Zanca, M. Spolaore, Oliviero Barana, Elena Gaio, P. Nielsen, M. Valisa, Francesco Gnesotto, Mario Bagatin, Vanni Toigo, M. Moresco, Piergiorgio Sonato, Lionello Marrelli, Tommaso Bolzonella, Roberto Pasqualotto, D. Terranova, A. Masiello, Rita Lorenzini, Alessandra Canton, Piero Martin, Matteo Zuin, S. Cappello, G. Rostagni, A. Cravotta, D. Bettella, S. Dal Bello, R. Piovan, Leonardo Giudicotti, P. Zaccaria, G. Regnoli, Emilio Martines, Adriano Luchetta, Paolo Franz, Giuseppe Zollino, Gabriele Manduchi, S. Ortolani, P. Scarin, D. Desideri, E. Spada, W. Baker, L. Apolloni, A. Buffa, Barbara Zaniol, Diego Marcuzzi, Giuseppe Chitarin, Luca Grando, A. Murari, N. Vianello, N. Pomaro, G. Preti, F. D'Angelo, L. Garzotti, G. Serianni, Mario Cavinato, Lorenzo Frassinetti, D. F. Escande, Fabio Sattin, Paolo Bettini, Roberto Cavazzana, Puiatti, M, Cappello, S, Lorenzini, R, Martini, S, Ortolani, S, Paccagnella, R, Sattin, F, Terranova, A, Bolzonella, T, Buffa, A, Canton, A, Carraro, L, Escande, D, Garzotti, L, Innocente, P, Marrelli, L, Martines, E, Scarin, P, Spizzo, G, Valisa, M, Zanca, P, Antoni, V, Apolloni, L, Bagatin, M, Baker, W, Barana, O, Bettella, D, Bettini, P, Cavazzana, R, Cavinato, M, Chitarin, G, Cravotta, A, D'Angelo, F, Dal Bello, S, De Lorenzi, A, Desideri, D, Fiorentin, P, Franz, P, Frassinetti, L, Gaio, E, Giudicotti, L, Gnesotto, F, Grando, L, Guo, S, Luchetta, A, Malesani, G, Manduchi, G, Marchiori, G, Marcuzzi, D, Martin, P, Masiello, A, Milani, F, Moresco, M, Murari, A, Nielsen, P, Pasqualotto, R, Pegourie, B, Peruzzo, S, Piovan, R, Piovesan, P, Pomaro, N, Preti, G, Regnoli, G, Rostagni, G, Serianni, G, Sonato, P, Spada, E, Spolaore, M, Taliercio, C, Telesca, G, Toigo, V, Vianello, N, Zaccaria, P, Zaniol, B, Zanotto, L, Zilli, E, Zollino, G, and Zuin, M

Subjects
Physics, Nuclear and High Energy Physics, Reversed field pinch, Condensed matter physics, Turbulence, Phase (waves), Magnetic confinement fusion, IMPROVED CONFINEMENT, reversed field pinch, Plasma, Mechanics, Condensed Matter Physics, POLOIDAL CURRENT DRIVE, pulsed poloidal current drive, REVERSED-FIELD-PINCH, SINGLE-HELICITY, Physics::Plasma Physics, RFP, HEAT-TRANSPORT, Transient (oscillation), Magnetohydrodynamics, PPCD, RFX, Dynamo
Abstract

In this paper, we analyse the main features of the pulsed poloidal current drive (PPCD) technique, used in the reversed field pinch configuration to achieve improved confinement conditions. In the RFX experiment, PPCD corresponds to a decrease of the magnetic fluctuations, to a peaking of the temperature profile, and to a reduced transport and plasma-wall interaction. A three-dimensional MHD nonlinear code and one-dimensional time-dependent transport models have been applied to study the effect of PPCD on the magnetic and plasma profiles. The three-dimensional MHD simulations show that the external inductive drive pinches and peaks the current profile driving the configuration through a transient phase, where the spontaneous turbulent dynamo action is quenched. The one-dimensional transport codes indicate that the experimental profile modifications associated with PPCD are consistent with a reduction of the stochastic transport.

Published
2003
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13. Plasma-wall interactions and radial electric fields in the reversed field pinch RFX

Author

Paolo Scarin, Barbara Zaniol, Fabio Sattin, Lorella Carraro, Maria Ester Puiatti, P. Zanca, M. Valisa, and M. Spolaore

Subjects
Nuclear and High Energy Physics, Reversed field pinch, Chemistry, Gyroradius, Perturbation (astronomy), Electron, Plasma, Fusion power, Ion, Nuclear physics, Nuclear Energy and Engineering, Physics::Plasma Physics, Electric field, General Materials Science, Atomic physics
Abstract

The radial electric field E r at the edge of the RFX plasma changes sign, from negative (inward) to positive, when an m =0 perturbation is externally applied. Similar behaviour had been previously observed in presence of wall locked ( m =1) modes, whereby the much stronger plasma–wall interaction made data interpretation more complex. The findings are compatible with the presence of an m =0, n =1 magnetic island. While in ordinary situations the edge losses of RFX are interpreted as dominated by finite Larmor radius ion effects, inside the island associated with the external perturbation the diffusion of the electrons is enhanced and exceeds the ion loss flux, thus reversing E r .

Published
2003
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14. Impurity influx studies in the RFX reversed field pinch

Author

Lorella Carraro, Fabio Sattin, E. Casarotto, Roberto Pasqualotto, M. Valisa, Paolo Scarin, and Maria Ester Puiatti

Subjects
Nuclear and High Energy Physics, Reversed field pinch, Screening effect, Chemistry, Plasma, Fusion power, Magnetic field, Photodiode, law.invention, Nuclear Energy and Engineering, Impurity, law, Physics::Plasma Physics, General Materials Science, Emission spectrum, Atomic physics
Abstract

The spectroscopic methods adopted to diagnose impurity and hydrogen influxes into the RFX plasma are described and the results of the observations are discussed. The impurity emission lines are currently monitored by means of narrow band interference filters and photodiode array equipped spectrometers, both absolutely calibrated. Influxes of carbon and oxygen are deduced from measurements of C II and O II lines and are related to the impurity content in the plasma core. Molecular band emission observations show a screening effect of the chemically sputtered products. The influx measurements are carried out over different viewing chords showing strong asymmetries in the plasma wall interactions, observed also by CCD cameras and related to strong magnetic field errors.

Published
2002
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15. New insights into MHD dynamics of magnetically confined plasmas from experiments in RFX

Author

Paolo Zanca, L. Fattorini, R. Piovan, R. Bartiromo, A. Boboc, Piero Martin, S. Costa, P. Zaccaria, L. Apolloni, Vanni Toigo, G. Malesani, Enrico Zilli, S. Martini, B. Pégourié, G. Rostagni, F. D'Angelo, Emilio Martines, Pietro Fiorentin, Barbara Zaniol, R. Paccagnella, Paolo Franz, Maria Ester Puiatti, P. Innoccente, C. Taliercio, Lorella Carraro, Giuseppe Telesca, Giuseppe Zollino, Roberto Pasqualotto, L. Garzotti, Antonio Ponno, Mario Bagatin, Giuseppe Marchiori, S. Cappello, Luca Zabeo, M. Moresco, Alvise Maschio, Giuseppe Chitarin, Leonardo Giudicotti, D. Terranova, Rita Lorenzini, N. Vianello, Fabio Sattin, Gabriele Manduchi, P. Nielsen, A. Intravaia, Paolo Bettini, A. Murari, M. Valisa, S. C. Guo, Lionello Marrelli, Dominique Escande, Tommaso Bolzonella, L. Tramontin, Luca Grando, M. Ogorman, Gianluca Spizzo, L. Zanotto, E. Spada, W. Baker, Alessandra Canton, G. Serianni, V. Antoni, F. Milani, Piergiorgio Sonato, Giovanni Preti, S. Ortolani, Simone Peruzzo, Elena Gaio, Roberto Cavazzana, Daniele Desideri, N. Pomaro, S. Dal Bello, Adriano Luchetta, P. Scarin, A. Buffa, M. Spolaore, Oliviero Barana, Francesco Gnesotto, A. De Lorenzi, A. Masiello, M. Viterbo, Martin, P, Martini, S, Antoni, V, Apolloni, L, Bagatin, M, Baker, W, Barana, O, Bartiromo, R, Bettini, P, Boboc, A, Bolzonella, T, Buffa, A, Canton, A, Cappello, S, Carraro, L, Cavazzana, R, Chitarin, G, Costa, S, D'Angelo, F, Dal Bello, S, De Lorenzi, A, Desideri, D, Escande, D, Fattorini, L, Fiorentin, P, Franz, P, Gaio, E, Garzotti, L, Giudicotti, L, Gnesotto, F, Grando, L, Guo, S, Innoccente, P, Intravaia, A, Lorenzini, R, Luchetta, A, Malesani, G, Manduchi, G, Marchiori, G, Marrelli, L, Martines, E, Maschio, A, Masiello, A, Milani, F, Moresco, M, Murari, A, Nielsen, P, O'Gorman, M, Ortolani, S, Paccagnella, R, Pasqualotto, R, Pegourie, B, Peruzzo, S, Piovan, R, Pomaro, N, Ponno, A, Preti, G, Puiatti, M, Rostagni, G, Sattin, F, Scarin, P, Serianni, G, Sonato, P, Spada, E, Spizzo, G, Spolaore, M, Taliercio, C, Telesca, G, Terranova, D, Toigo, V, Tramontin, L, Valisa, M, Vianello, N, Viterbo, M, Zabeo, L, Zaccaria, P, Zanca, P, Zaniol, B, Zanotto, L, Zilli, E, and Zollino, G

Subjects
Physics, plasma confinement, Nuclear and High Energy Physics, Resistive touchscreen, Condensed matter physics, Reversed field pinch, mode locking, Magnetic confinement fusion, Laminar flow, reversed field pinch, Plasma, Condensed Matter Physics, Amplitude, magnetic configuration, Physics::Plasma Physics, Quantum electrodynamics, RFP, tearing mode, Magnetohydrodynamics, RFX, Dynamo
Abstract

The experimental and theoretical activity performed in the RFX device has allowed a deeper insight into the MHD properties of the reversed field pinch (RFP) configuration. A set of successful experiments has demonstrated the possibility of influencing both the amplitude and the spectrum of the magnetic fluctuations which characterize the RFP configuration. A new regime (quasi-single-helicity states) where the dynamo mechanism works in a nearly laminar way and a helical core plasma is produced has been investigated. With these studies a reduction of magnetic chaos has been obtained. The continuous rotation of wall locked resistive tearing modes has been obtained by an m = 0 rotating perturbation. This perturbation induces rotation of m = 1 non-linearly coupled modes.

Published
2000
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16. Recent progress in reversed field pinch research in the RFX experiment

Author

Paolo Innocente, Enrico Zilli, Piero Martin, A. Masiello, S. Martini, S. C. Guo, Maria Ester Puiatti, Gianluca Spizzo, Piergiorgio Sonato, M. Viterbo, G. Malesani, F. Milani, Alessandra Canton, T. Bolzonella, S. Cappello, G. Serianni, Giuseppe Zollino, Giuseppe Telesca, S. Vitturi, D. Gregoratto, R. Pugno, Roberto Cavazzana, L. Garzotti, Mario Bagatin, M. Moresco, F. Bellina, Simone Peruzzo, Elena Gaio, Alvise Maschio, V. Antoni, Leonardo Giudicotti, P. Scarin, D. Desideri, A. Buffa, R. Bilato, Lorella Carraro, D. F. Escande, L. Apolloni, Gabriele Manduchi, A. De Lorenzi, E. Spada, W. Baker, Fabio Sattin, L. Tramontin, R. Piovan, D. Terranova, P. Zaccaria, S. Ortolani, A. Intravaia, Paolo Bettini, F. D'Angelo, P. Zanca, R. Bartiromo, Pietro Fiorentin, Emilio Martines, R. Paccagnella, N. Pomaro, Cesare Taliercio, M. Spolaore, Paolo Franz, Francesco Gnesotto, G. De Pol, Vanni Toigo, S. Costa, Giuseppe Chitarin, Adriano Luchetta, Roberto Pasqualotto, Giuseppe Marchiori, M. Valisa, Lionello Marrelli, A. Murari, G. Rostagni, Bartiromo, R, Buffa, A, Antoni, V, Apolloni, L, Bagatin, M, Baker, W, Bellina, F, Bettini, P, Bilato, R, Bolzonella, T, Canton, A, Cappello, S, Carraro, L, Cavazzana, R, Chitarin, G, Costa, S, D'Angelo, F, De Lorenzi, A, De Pol, G, Desideri, D, Escande, D, Fiorentin, P, Franz, P, Gaio, E, Garzotti, L, Giudicotti, L, Gnesotto, F, Gregoratto, D, Guo, S, Innocente, P, Intravaia, A, Luchetta, A, Malesani, G, Manduchi, G, Marchiori, G, Marrelli, L, Martin, P, Martines, E, Martini, S, Maschio, A, Masiello, A, Milani, F, Moresco, M, Murari, A, Ortolani, S, Paccagnella, R, Pasqualotto, R, Peruzzo, S, Piovan, R, Pomaro, N, Pugno, R, Puiatti, M, Rostagni, G, Sattin, F, Scarin, P, Serianni, G, Sonato, P, Spada, E, Spizzo, G, Spolaore, M, Taliercio, C, Telesca, G, Terranova, D, Toigo, V, Tramontin, L, Valisa, M, Viterbo, M, Vitturi, S, Zaccaria, P, Zanca, P, Zilli, E, and Zollino, G

Subjects
Physics, Nuclear and High Energy Physics, Reversed field pinch, Turbulence, reversed field pinch, Plasma, Condensed Matter Physics, Effective nuclear charge, Computational physics, Nuclear magnetic resonance, Amplitude, Thermal conductivity, Physics::Plasma Physics, Electric field, RFP, Current (fluid), RFX
Abstract

The article presents an overview of recent experimental results obtained on the RFX device. The authors obtained and studied a reversed field pinch plasma with a plasma current of up to 1 MA, negligible radiation losses and low effective charge. The local power and particle balance shows that in standard operation the plasma core is dominated by magnetic turbulence and that the global confinement is mainly provided by the edge region, where a strongly sheared radial electric field is present. With poloidal current drive the amplitude of magnetic fluctuations and the thermal conductivity of the plasma core are reduced, leading to improved confinement. Reduced heat transport is also observed when the width of the n spectrum of magnetic fluctuations is reduced.

Published
1999
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17. Scaling Of Local Core Transport With Lundquist Number In The Reversed Field Pinch

Author

D. Terranova, L. Marrelli, Piero Martin, Paolo Scarin, S. Martini, Maria Ester Puiatti, Gianluca Spizzo, Tommaso Bolzonella, A. Intravaia, A. Canton, M. Valisa, Paolo Franz, Paolo Innocente, Roberto Pasqualotto, and A. Murari

Subjects
Physics, Condensed matter physics, Reversed field pinch, Turbulence, Physics::Plasma Physics, Physics::Space Physics, General Physics and Astronomy, Electron temperature, Magnetic reconnection, Lundquist number, Plasma, Scaling, Dynamo
Abstract

We investigate the scaling of the core energy transport with the magnetic Lundquist number $S$ in the reversed field pinch. We analyze for the first time the electron temperature and thermal conductivity profiles and the dynamo magnetic fluctuations in a wide range of stationary plasmas produced in the RFX device at plasma current ranging between 0.2 and 1.1 MA. When $S$ increases we measure an improvement of core confinement associated with the strengthening of the internal electron temperature profiles gradient and with the decrease of magnetic turbulence. This shows that core energy transport is related with magnetic fluctuations and can be ameliorated in high $S$ regimes.

Published
1999
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18. Overview of the RFX-mod fusion science programme

Author

Piergiorgio Sonato, S. Dal Bello, Maria Ester Puiatti, Piero Martin, A. Fiorentin, Stefano Munaretto, F. Fellin, G. De Masi, M. Gobbin, Silvia Spagnolo, M. Furno Palumbo, P. Zaccaria, E. Gazza, M. Recchia, Raul Sanchez, Karsten McCollam, G. L. Trevisan, E. Spada, Alessandra Canton, Matteo Zuin, Ivo Furno, Christian Theiler, A. Zamengo, J.Q. Dong, Emilio Martines, B. E. Chapman, M. Dalla Palma, Paolo Franz, M. Brombin, V. Rigato, J. Framarin, Antonio Barbalace, P. Piovesan, Nicola Pilan, Donald A. Spong, Roberto Paccagnella, Wolf-Dieter Schneider, Barbara Zaniol, Fabio Villone, Leonardo Giudicotti, M. De Muri, T.C. Luce, R. Piovan, A. Ruzzon, V. Antoni, Giuseppe Zollino, Emanuele Sartori, Yueqiang Liu, G. Rostagni, M. Baruzzo, Manabu Takechi, Yongkyoon In, R. Delogu, Fulvio Auriemma, J. A. Alonso, M. Barp, C. Piron, D. Bonfiglio, Go Matsunaga, Enrico Zilli, G. Ciaccio, S. Martini, L. Piron, Marco Barbisan, Songfen Liu, M. Veranda, A. Scaggion, Giuseppe Chitarin, N. Pomaro, Luis Chacon, James D. Hanson, L. Apolloni, Yoichi Hirano, M. Spolaore, Francesco Gnesotto, F. Avino, Nicolò Marconato, M. Valente, Alberto Ferro, Fabio Sattin, Pierluigi Veltri, Gabriele Manduchi, L. Zanotto, C. Hidalgo, Paolo Innocente, Simona Barison, L. Novello, Italo Predebon, Rita Lorenzini, David Terranova, Luca Grando, Zhirui Wang, Vanni Toigo, M. Boldrin, M. Bigi, Adriano Luchetta, Paolo Bettini, Erik Olofsson, Andrea Rizzolo, Gianluigi Serianni, Anton Soppelsa, Cesare Taliercio, Roscoe White, C. Finotti, Susanna Cappello, N. Fonnesu, Roberto Pasqualotto, Paolo Scarin, R. Bilel, Shunsuke Ide, Alessandro Fassina, A. Maistrello, D. Carralero, Matteo Agostini, W. A. Cooper, P. Zanca, A. Buffa, Piero Agostinetti, G. Mazzitelli, X. Y. Xu, S. Fiameni, M. Moresco, John M. Finn, Lionello Marrelli, B. Momo, Tommaso Bolzonella, Nicola Vianello, Giuseppe Marchiori, D.K. Mansfield, M. Valisa, M. Okabayashi, S. C. Guo, Dominique Escande, Lorella Carraro, A. Pesce, M. Pavei, F. Ghezzi, Roberto Cavazzana, Satoru Kiyama, W. A. Gonzales, Simone Peruzzo, S.P. Hirshman, Elena Gaio, T. Barbui, Hajime Sakakita, G.L. Jackson, J. S. Sarff, Ambrogio Fasoli, D. Lopez Bruna, A. L. Roquemore, Federica Bonomo, F. Fantini, Lorenzo Frassinetti, C. Bustreo, Diego Marcuzzi, G. L. Delzanno, Gianluca Spizzo, A. De Lorenzi, Martin, P, Puiatti, M, Agostinetti, P, Agostini, M, Alonso, J, Antoni, V, Apolloni, L, Auriemma, F, Avino, F, Barbalace, A, Barbisan, M, Barbui, T, Barison, S, Barp, M, Baruzzo, M, Bettini, P, Bigi, M, Bilel, R, Boldrin, M, Bolzonella, T, Bonfiglio, D, Bonomo, F, Brombin, M, Buffa, A, Bustreo, C, Canton, A, Cappello, S, Carralero, D, Carraro, L, Cavazzana, R, Chacon, L, Chapman, B, Chitarin, G, Ciaccio, G, Cooper, W, Dal Bello, S, Dalla Palma, M, Delogu, R, De Lorenzi, A, Delzanno, G, De Masi, G, De Muri, M, Dong, J, Escande, D, Fantini, F, Fasoli, A, Fassina, A, Fellin, F, Ferro, A, Fiameni, S, Finn, J, Finotti, C, Fiorentin, A, Fonnesu, N, Framarin, J, Franz, P, Frassinetti, L, Furno, I, Palumbo, M, Gaio, E, Gazza, E, Ghezzi, F, Giudicotti, L, Gnesotto, F, Gobbin, M, Gonzales, W, Grando, L, Guo, S, Hanson, J, Hidalgo, C, Hirano, Y, Hirshman, S, Ide, S, In, Y, Innocente, P, Jackson, G, Kiyama, S, Liu, S, Liu, Y, Lopez Bruna, D, Lorenzini, R, Luce, T, Luchetta, A, Maistrello, A, Manduchi, G, Mansfield, D, Marchiori, G, Marconato, N, Marcuzzi, D, Marrelli, L, Martini, S, Matsunaga, G, Martines, E, Mazzitelli, G, Mccollam, K, Momo, B, Moresco, M, Munaretto, S, Novello, L, Okabayashi, M, Olofsson, E, Paccagnella, R, Pasqualotto, R, Pavei, M, Peruzzo, S, Pesce, A, Pilan, N, Piovan, R, Piovesan, P, Piron, C, Piron, L, Pomaro, N, Predebon, I, Recchia, M, Rigato, V, Rizzolo, A, Roquemore, A, Rostagni, G, Ruzzon, A, Sakakita, H, Sanchez, R, Sarff, J, Sartori, E, Sattin, F, Scaggion, A, Scarin, P, Schneider, W, Serianni, G, Sonato, P, Spada, E, Soppelsa, A, Spagnolo, S, Spolaore, M, Spong, D, Spizzo, G, Takechi, M, Taliercio, C, Terranova, D, Theiler, C, Toigo, V, Trevisan, G, Valente, M, Valisa, M, Veltri, P, Veranda, M, Vianello, N, Villone, F, Wang, Z, White, R, Xu, X, Zaccaria, P, Zamengo, A, Zanca, P, Zaniol, B, Zanotto, L, Zilli, E, Zollino, G, Zuin, M, and Mazzitelli, G.

Subjects
Nuclear and High Energy Physics, RFX-mod, Tokamak, Strong interaction, reversed field pinch, law.invention, Magnetohydrodynamics, law, RFP, Fusion, Safety factor, Reversed field pinch, Flow transport, Settore FIS/01 - Fisica Sperimentale, Iter tokamak, Fusion power, IAEA Fusion Energy Conference, Science and Technology, Condensed Matter Physics, Active control, Plasma parameter, Plasma devices, Systems engineering, Fusion devices, Magnetic configuration, Stellarator
Abstract

This paper reports the highlights of the RFX-mod fusion science programme since the last 2010 IAEA Fusion Energy Conference. The RFX-mod fusion science programme focused on two main goals: exploring the fusion potential of the reversed field pinch (RFP) magnetic configuration and contributing to the solution of key science and technology problems in the roadmap to ITER. Active control of several plasma parameters has been a key tool in this endeavour. New upgrades on the system for active control of magnetohydrodynamic (MHD) stability are underway and will be presented in this paper. Unique among the existing fusion devices, RFX-mod has been operated both as an RFP and as a tokamak. The latter operation has allowed the exploration of edge safety factor q edge < 2 with active control of MHD stability and studies concerning basic energy and flow transport mechanisms. Strong interaction has continued with the stellarator community in particular on the physics of helical states and on three-dimensional codes. © 2013 IAEA, Vienna.

Published
2013
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19. Advances in understanding RFX-mod helical plasmas

Author

Gianluca Spizzo, Anton Soppelsa, Luca Grando, Lionello Marrelli, Tommaso Bolzonella, Alessandra Canton, Matteo Zuin, Alessandro Fassina, Fulvio Auriemma, M. Valisa, Rita Lorenzini, M. Gobbin, Paolo Scarin, A. Ruzzon, L. Zanotto, Lorella Carraro, Maria Ester Puiatti, S. Dal Bello, David Terranova, Paolo Innocente, Italo Predebon, Roberto Cavazzana, Emilio Martines, Paolo Franz, Carraro, L, Innocente, P, Auriemma, F, Cavazzana, R, Fassina, A, Franz, P, Gobbin, M, Predebon, I, Ruzzon, A, Spizzo, G, Terranova, D, Bolzonella, T, Canton, A, Dal Bello, S, Grando, L, Lorenzini, R, Marrelli, L, Martines, E, Puiatti, M, Scarin, P, Soppelsa, A, Valisa, M, Zanotto, L, and Zuin, M

Subjects
Physics, Nuclear and High Energy Physics, RFX-mod, Safety factor, Reversed field pinch, reversed field pinch, Electron, Plasma, Condensed Matter Physics, Thermal diffusivity, Helicity, TRANSPORT, Magnetic field, quasi-single helicity, REVERSED-FIELD PINCH, RFP, Electron temperature, QSH, Atomic physics
Abstract

High current (Ip = 1-1.7 MA) operations in the ohmic reversed field pinch RFX-mod spontaneously access the quasi-single helicity (QSH) regime, in which the magnetic dynamics is dominated by the innermost resonant mode (m = 1, n = -7), the magnetic chaos level is reduced and the internal magnetic field configuration is close to a pure helix. During the QSH state strong electron temperature (Te) gradients can show up, identifying an electron transport barrier (Puiatti 2011 Nucl. Fusion 51 073038). Results and advancements obtained in recent RFX-mod high current campaigns are reported in this paper. The best plasma performances at high Ip (i.e. high power) in QSH regimes have been reached with marginally reversed values of the safety factor q at the edge (-0.01 < qa < 0) when the lowest amplitudes of secondary m = 0, 1 modes are obtained. The QSH magnetic states are not stationary and show back transitions to the multiple helicity regime; however, the total persistency of the QSH is found to increase with the plasma current and at Ip > 1.5 MA it exceeds 90% of the plasma current flat-top. The high electron temperature gradients (>2 keV m-1) do not persist throughout the magnetic QSH cycle, as documented by a new high time resolution SXR double-filter multichord system, however, they last 5 to 10 ms, more than the energy confinement time. In the barrier region the profile of the electron heat diffusivity χe falls around 2-20 m2 s-1, well below ∼40-100 m-2 s-1 typical of the outer regions. The experimental evaluation of χe across the thermal barrier is consistent with a microtearing mode driven heat transport.

Published
2013
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