N. Vianello
A5028106100- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Fusion materials and technologies
- Superconducting Materials and Applications
- Plasma Diagnostics and Applications
- Particle accelerators and beam dynamics
- Solar and Space Plasma Dynamics
- Laser-Plasma Interactions and Diagnostics
- Nuclear reactor physics and engineering
- Fluid Dynamics and Turbulent Flows
- Laser-induced spectroscopy and plasma
- Complex Systems and Time Series Analysis
- Physics of Superconductivity and Magnetism
- Electrohydrodynamics and Fluid Dynamics
- Geomagnetism and Paleomagnetism Studies
- Metal and Thin Film Mechanics
- Meteorological Phenomena and Simulations
- Magnetic Field Sensors Techniques
- Quantum chaos and dynamical systems
- Statistical Mechanics and Entropy
- Theoretical and Computational Physics
- Semiconductor materials and devices
- Earthquake Detection and Analysis
- High-Energy Particle Collisions Research
- Atomic and Molecular Physics
National Agency for New Technologies, Energy and Sustainable Economic Development
2014-2024
University of Padua
2011-2024
Institute for the Science and Technology of Plasmas
2022-2023
Culham Science Centre
2022
Culham Centre for Fusion Energy
2022
National Centre for Nuclear Research
2021
Royal Military Academy
2020
École Polytechnique Fédérale de Lausanne
2015-2017
Institute of Plasma Physics
2017
Consorzio Venezia Ricerche
2016
Divertor detachment is explored on the TCV tokamak in alternative magnetic geometries. Starting from typical single-null shapes, poloidal flux expansion at outer strikepoint varied by a factor of 10 to investigate X-divertor characteristics, and total 70 study properties super-X divertor. The effect an additional X-point near target investigated divertors. Detachment studied these plasmas during Ohmic density ramps with ion B drift away primary X-point. threshold, depth detachment, stability...
In a wide variety of natural and laboratory magnetized plasmas, filaments appear as result interchange instability. These convective structures substantially enhance transport in the direction perpendicular to magnetic field. According filament models, their propagation may follow different regimes depending on parallel closure charge conservation. This is paramount importance fusion high collisionality scrape-off layer trigger regime transition leading strongly enhanced particle fluxes....
Self-consistent full-size turbulent-transport simulations of the divertor and SOL existing tokamaks have recently become feasible. This enables direct comparison turbulence against experimental measurements. In this work, we perform a series diverted Ohmic L-mode discharges on TCV tokamak, building first-of-a-kind dataset for validation edge models. dataset, referred to as TCV-X21, contains measurements from 5 diagnostic systems -- giving total 45 1- 2-D observables in two toroidal magnetic...
Abstract Since the publication of review Progress in ITER Physics Basis (PIPB) 2007, significant progress has been made understanding processes at plasma-material interface. This review, part ITPA Nuclear Fusion Special Issue On Path to Burning Plasma Operation , presents these developments, focusing on key areas such as physics plasma exhaust, interactions, and properties plasma-facing materials their evolution under exposure. The coordinated efforts Topical Group Scrape-Off Layer Divertor...
A summary of recent results on filamentary transport, mostly obtained with the ASDEX-Upgrade tokamak (AUG), is presented and discussed in an attempt to produce a coherent picture scrape-off layer (SOL) transport. clear correlation found between L-mode density shoulder formation outer midplane transition sheath-limited inertial regimes. Divertor collisionality be parameter triggering transition. reduction ion temperature takes place far SOL after transition, both for background filaments....
A detailed cross-device investigation on the role of filamentary dynamics in high-density regimes has been performed within EUROfusion framework, comparing ASDEX Upgrade (AUG) and TCV tokamaks. Both devices run density ramp experiments at different levels plasma current, keeping toroidal field or q95 constant order to disentangle parallel connection length current. During scan a field, both scrape-off layer (SOL) profiles tend develop clear SOL shoulder lower edge whenever current is...
Abstract The work describes the pedestal structure, transport and stability in an effective mass ( A eff ) scan from pure deuterium to tritium plasmas using a type I ELMy H-mode dataset which key parameters that affect behaviour (normalized pressure, ratio of separatrix density density, ion Larmor radius, collisionality rotation) are kept as constant possible. Experimental results show significant increase at top with increasing , modest reduction temperature pressure. variations heights...
Abstract The impact of plasma shaping on the properties high density H-mode scrape-off layer (SOL) profiles and transport at outer midplane has been investigated Tokamakà configuration variable. experimental dataset acquired by evolving upper triangularity while keeping other parameters constant. scan comprises <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>δ</mml:mi> <mml:mrow> <mml:mi mathvariant="normal">u</mml:mi>...
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
The RFX-mod machine (Sonato et al 2003 Fusion Eng. Des. 66 161) recently achieved, for the first time in a reversed-field pinch, high plasma current up to 1.6 MA with good confinement. Magnetic feedback control of magnetohydrodynamic instabilities was essential reach goal. As is raised, spontaneously accesses new helical state, starting from turbulent multi-helical conditions. Together this raise, ratio between dominant and secondary mode amplitudes increases continuous way. This brings...
This paper presents turbulence investigations in the scrape-off layer (SOL) of ASDEX Upgrade ohmic, L-mode and H-mode discharges using electrostatic electromagnetic probes. Detailed studies are performed on small scale ELM filaments. Simultaneous measurements floating plasma potential fluctuations revealed significant differences between these quantities. Large errors can occur when electric field is extracted from measurements, even ohmic discharges. Turbulence plasmas show existence...
Abstract The recent deuterium–tritium campaign in JET-ILW (DTE2) has provided a unique opportunity to study the isotope dependence of L-H power threshold an ITER-like wall environment (Be and W divertor). Here we present results from dedicated transition experiments at JET-ILW, documenting tritium plasmas, comparing them with matching deuterium hydrogen datasets. From earlier it is known that as plasma isotopic composition changes deuterium, through varying deuterium/hydrogen concentrations,...
Abstract A set of dedicated H-mode discharges with constant heating power combining Neutral Beam Injection and Electron Cyclotron Resonance Heating have been executed at the ASDEX Upgrade tokamak using a high triangularity magnetic geometry in order to investigate impact filamentary transport divertor non-divertor components. The evolution upstream scrape-off layer (SOL) profiles correlated separatrix quantities, mostly turbulence control parameter <mml:math...
Abstract Three-dimensional turbulence simulations of a RFX-mod diverted plasma are performed in the presence biasing electrode. The show strong suppression turbulent transport caused by induced E × B flow shear, which leads to formation an edge barrier with pedestal-like structure, qualitative agreement experiments. shear voltage is also observed proximity density limit crossing, suggesting that may allow for larger maximum achievable values. By leveraging simulation results, theoretical...
Abstract This study investigates the dependence of radial electric field (Er) on line-averaged density in JET L-mode plasmas, utilizing Doppler backscattering measurements. Density ramp discharges up to limit are analyzed investigate physical processes that determine edge Er profile. At low densities, profile at midplane exhibits a pronounced peak near scrape-off layer (SOL) and shallow well inside separatrix. As increases, SOL diminishes quickly deepens until Greenwald fraction fGW ≈ 0.8,...
Abstract JET returned to deuterium-tritium operations in 2023 (DTE3 campaign), approximately two years after DTE2. DTE3 was designed as an extension of JET's 2022-2023 deuterium campaigns, which focused on developing scenarios for ITER and DEMO, integrating in-depth physics understanding control schemes. These were evaluated with mixed D-T fuel, using the only remaining tritium-capable tokamak until its closure 2023. A core-edge-SOL integrated H-mode scenario developed tested D-T, showing...
Research towards a plasma exhaust solution for fusion power plant aims at validating edge physics models, strengthening predictive capabilities and improving the divertor configuration. The TCV tokamak is extensively used to investigate extent that geometric configuration modifications can affect performance. Recent experiments continue previous detachment studies of Ohmically heated L-mode plasmas in standard single-null configurations, benefitting from range improved diagnostic...
A set of Ohmic density ramp experiments addressing the role parallel connection length in modifying scrape off layer (SOL) properties has been performed on TCV tokamak. The modified by varying poloidal flux expansion fx. It will be shown that this modification does not influence neither detachment threshold, nor development a flat SOL profile which instead depends strongly increase core line average density. upstream profile, with appearance what is generally called shoulder, related to...
A large database of reciprocating probe data from the edge plasma TCV (Tokamak à Configuration Variable) is used to test radial velocity scalings filaments analytical theory [Myra et al., Phys. Plasmas 13, 112502 (2006)]. The measured velocities are mainly scattered between zero and a maximum which varies as function size collisionality in agreement with scalings. scatter consistent mechanisms that tend slow individual filaments. While were clustered 0.5 2 km/s, minority reached outward high...
Coherent structures identified in two reversed field pinch experiments are interpreted as a dynamic balance of dipolar and monopolar vortices growing evolving under the effect ExB flow shear. For first time their contribution to anomalous transport has been estimated fusion related plasmas, showing that they can account for up 50% total plasma diffusivity. The experimental findings indicate diffusion coefficient associated with coherent depends on relative population types is minimum when...
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...
Recently, a European transport project has been carried out among several fusion devices for studying the possible link between mean radial electric field ( E r ), long-range correlation (LRC) and edge bifurcations in plasmas. The main results reported this paper include: (i) discovery of low-frequency LRCs potential fluctuations which are amplified during development using electrode biasing spontaneous sheared flows stellarators tokamaks. Evidence nonlocal energy transfer geodesic acoustic...
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...