A5071402825- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Plasma Diagnostics and Applications
- Laser-Plasma Interactions and Diagnostics
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Fusion materials and technologies
- Solar and Space Plasma Dynamics
- Atomic and Molecular Physics
- Medical Imaging Techniques and Applications
- Laser-induced spectroscopy and plasma
- Advanced MRI Techniques and Applications
- Nuclear Physics and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Geomagnetism and Paleomagnetism Studies
- Advanced X-ray and CT Imaging
- Advanced X-ray Imaging Techniques
- Electron and X-Ray Spectroscopy Techniques
- Nuclear reactor physics and engineering
- Quantum chaos and dynamical systems
- Electrostatic Discharge in Electronics
- Particle Accelerators and Free-Electron Lasers
- Characterization and Applications of Magnetic Nanoparticles
- Advanced Data Storage Technologies
- Particle Detector Development and Performance
National Agency for New Technologies, Energy and Sustainable Economic Development
2012-2024
University of Padua
1999-2023
Istituto Nazionale per la Fisica della Materia
1999-2004
Klinik und Poliklinik für Hals-Nasen-Ohren-Heilkunde
2003
University of California, Los Angeles
2002
Medical University of Vienna
2001
Istituto Nazionale di Fisica Nucleare, Sezione di Padova
2000
Forschungszentrum Jülich
1997
The reversed field pinch (RFP) is a configuration for plasma magnetic confinement. It has been traditionally viewed as dominated by bath of MHD instabilities producing chaos and high energy transport. We report experimental results which go beyond this view. They show decrease the formation coherent helical structure in plasma, whose imaging temperature profile are provided first time. These quasi-single-helicity states observed both transiently stationary conditions. last case consistent...
We report the results of an experimental and theoretical international project dedicated to study quasi-single helicity (QSH) reversed field pinch (RFP) plasmas. The has involved several RFP devices numerical codes. It appears that QSH spectra are a robust feature common all experiments. Our expand reinforce evidence formation self-organized states with one dominant helical mode (Ohmic SH state) is approach complementary active control magnetic turbulence improve confinement in steady state RFP.
Stable operation with control on magnetohydrodynamic modes has been obtained in the modified reversed field experiment employing a set of 192 feedback controlled saddle coils. Improvements plasma temperature, confinement (twofold), and pulse length (threefold) and, as consequence magnetic fluctuation reduction, strong mitigation plasma-wall interaction mode locking are reported.Received 27 January 2006DOI:https://doi.org/10.1103/PhysRevLett.97.075001©2006 American Physical Society
Abstract. This study investigates the potential of using aerodynamic pressure time series measurements to detect structural damage in elastic, aerodynamically loaded structures. Our work is motivated by increase dimensions modern wind turbine blade designs, whose complex behavior necessitates adoption improved simulation and monitoring solutions. In refining tracking interactions their effects on such structures, we propose exploit measurements, available from a novel, cost-effective...
Abstract A statistical analysis of plasma temperature profiles in RFX-mod plasmas reveals that improved thermal structures can be observed chaotic magnetic topologies, specifically the so-called multiple helicity (MH) states. The feature high electron temperatures, up to 1.2 keV, enhanced gradient and radial extension which have been conventionally only 
 attainable organized quasi-single (QSH) reported here suggests a possible role m = 1, n −7 −8 modes (where are poloidal toroidal...
Reduction of core-resonant m=1 magnetic fluctuations and improved confinement in the Madison Symmetric Torus [Dexter et al., Fusion Technol. 19, 131 (1991)] reversed-field pinch have been routinely achieved through control surface poloidal electric field, but it is now known that has limited part by edge-resonant m=0 fluctuations. Now, refined field control, plus toroidal possible to reduce simultaneously This allowed high-energy runaway electrons, possibly indicative flux-surface...
SXR cross-sectional distributions measured in the European reversed field pinch (RFP) experiment RFX by means of a tomographic diagnostic are described. Various reconstruction techniques have been compared. A correction technique to minimize systematic effect due non-identical thicknesses material filters has developed. number experimental situations explored, and study correlation between MHD properties plasma made. The analysis concentrates both on standard discharges recently discovered...
RFX-mod is a reversed field pinch (RFP) experiment equipped with system that actively controls the magnetic boundary. In this paper we describe results of new control algorithm, clean mode (CMC), in which aliasing sideband harmonics generated by discrete saddle coils corrected real time. CMC operation leads to smoother (i.e. more axisymmetric) Tearing modes rotate (up 100 Hz) and partially unlock. Plasma–wall interaction diminishes due decrease non-axisymmetric shift plasma column. With...
With the exploration of MA plasma current regime in up to 0.5 s long discharges, RFX-mod has opened new and very promising perspectives for reversed field pinch (RFP) magnetic configuration, made significant progress understanding improving confinement controlling stability. A big leap with respect previous knowledge expectations on RFP physics performance been by since last 2006 IAEA Fusion Energy Conference. self-organized helical equilibrium experimentally achieved (the Single Helical...
Abstract The RFX-mod2 installation is planned to be completed by 2024 and the start of operations expected in 2025. high flexibility machine (already tested previous RFX-mod experiment) allows operation Reversed Field Pinch tokamak configuration as well ultra-low q pulses. In this work we present predictive analysis on transport, performances plasma control view first experimental campaigns.
This paper reports experimental results showing that coherent helical structures are formed in the reversed field pinch (RFP) self-organizing plasma core as a result of transitions to states where n-spectrum m=1 modes is dominated by single (1,nmax) geometrical helicity. These dubbed quasi-single helicity (QSH) states. Their magnetic and thermal properties measured reverse experiment (RFX) [G. Rostagni, Fusion Eng. Des. 25, 301 (1995)] device described. The present theoretical understanding...
Optimization of machine operation, including plasma position control, density control and especially feedback on multiple magnetohydrodynamic modes, has led RFX-mod to operate reliably at 1.5 MA, the highest current ever achieved a reversed field pinch (RFP). At high low magnetic topology spontaneously self-organizes in an Ohmical helical symmetry, with new axis helically twisting around geometrical torus. The separatrix island disappears leaving wide symmetric thermal structure large...
This paper reports the most recent experimental results on quasi-single helicity (QSH) reversed field pinch (RFP) plasmas. QSH is considered a key element towards full realization of theoretically predicted single (SH) RFP. The SH RFP, where an individual resistive kink mode and its harmonics drive dynamo electric field, to have superior confinement performance with respect standard multiple (MH) state. Magnetic chaos in fact strongly reduced which therefore retains all positive features RFP...
The reversed field pinch configuration is characterized by the presence of magnetic structures both in core and at edge: core, high plasma current spontaneous development a helical structure accompanied appearance internal electron transport barriers; edge strong pressure gradients, identifying an barrier, are observed too, related to position reversal surface.
RFX-mod [Sonato et al., Fusion Eng. Des. 66, 161 (2003)] exploits its 192 active coils in both reversed-field pinch (RFP) and tokamak configurations with varying degrees of 3D shaping, providing also a test bed for validating stellarator codes nonlinear magnetohydrodynamic codes. This makes unique flexible facility comparative studies on shaping control. The paper discusses how fields allow access to RFP advanced regimes. are used feedback control Single Helicity (SH) equilibria 1/7 helicity...
An overview of recent results from the MST programme on physics important for advancement reversed field pinch (RFP) as well improved understanding toroidal magnetic confinement more generally is reported. Evidence classical ions in RFP provided by analysis impurity and energetic created 1 MW neutral beam injection (NBI). The first appearance energetic-particle-driven modes NBI a plasma described. plasmas robustly access quasi-single-helicity state that has commonalities to stellarator...
This paper reports the main recent results of RFX-mod fusion science activity.The device is characterized by a unique flexibility in terms accessible magnetic configurations.Axisymmetric and helically shaped Reversed-field pinch equilibria have been studied, along with tokamak plasmas wide range q(a) regimes (spanning from 4 down to 1.2 values).The full configurations between two, so-called ultra low-q ones, has explored, aim studying specific physical issues common all equilibria, such as,...
Nonlinear fluid modelling predictions of qualitatively new self-organized helical states in the reversed-field pinch configuration are confirmed by experiments RFX-mod device. The realized using a seed edge magnetic field, which can impose its pitch to whole plasma. In simulations, we show increased order and reduced transport field lines regimes with twist non-resonant mode. We reveal existence Cantori, encompassing region characterized conserved surfaces, act as barriers lines. This opens...
Evidence of a self-organized collapse towards narrow spectrum magnetic instabilities in the Madison Symmetric Torus [R. N. Dexter, D. W. Kerst, T. Lovell, S. C. Prager, and J. Sprott, Fusion Technol. 19, 131 (1991)] reversed field pinch device is presented. In this collapsed state, dubbed quasi-single helicity (QSH), modes condenses spontaneously to one dominant mode more completely than ever before observed. The amplitudes all but largest m=1 decrease QSH states. New results about thermal...
The modified RFX is a very flexible device used for variety of control schemes MHD instabilities and advanced reverse field pinch scenarios. Relative to the previous machine, RFX-mod has thin Cu shell with vertical penetration time τS, lowered from 450 50 ms shell/plasma proximity b/a = 1.24–1.1. Toroidal equilibrium feedback-controlled new power supplies provide better B control. Newly designed graphite tiles protect vessel localized deposition. A mesh 192 external saddle coils, supervised...
The full three-dimensional (3D) approach is now becoming an important issue for all magnetic confinement configurations. It a necessary condition the stellarator but also tokamak and reversed field pinch (RFP) cannot be completely described in axisymmetric framework. For RFP observation of self-sustained helical configurations with improved plasma performances require better description order to assess new view on this configuration. In framework configuration studies RFX-mod have been...
This paper summarizes the main achievements of RFX fusion science program in period between 2008 and 2010 IAEA Fusion Energy Conferences. RFX-mod is largest reversed field pinch world, equipped with a system 192 coils for active control MHD stability. The discovery understanding helical states electron internal transport barriers core temperature >1.5 keV significantly advances perspectives configuration. Optimized experiments plasma current up to 1.8 MA have been realized, confirming...
The study of electron temperature profiles quasi-single helical states (QSH) in RFX-Mod (and, general, other RFP machines) was carried out the past mainly using Thomson scattering, thus being limited to a time resolution order some milliseconds and collection single, isolated cases, which displayed clear transport barriers. A new multichord double filter SXR spectrometer developed installed. Temperature are now measured up frequency kHz, allowing one determine entire evolution during QSH...
Single Helical Axis (SHAx) configurations are emerging as the natural state for high current reversed field pinch (RFP) plasmas. These states feature presence of transport barriers in core plasma. Here we present a method computing equilibrium magnetic surfaces these force-free approximation, which has been implemented SHEq code. The is based on superposition zeroth order axisymmetric and first helical perturbation computed according to Newcomb's equation supplemented with edge measurements....