L. Frassinetti
A5025236752- Magnetic confinement fusion research
- Fusion materials and technologies
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Laser-Plasma Interactions and Diagnostics
- Particle accelerators and beam dynamics
- Nuclear reactor physics and engineering
- Plasma Diagnostics and Applications
- Solar and Space Plasma Dynamics
- Meteorological Phenomena and Simulations
- Nuclear Physics and Applications
- Fluid Dynamics and Turbulent Flows
- Plasma and Flow Control in Aerodynamics
- Nuclear Materials and Properties
- Atomic and Subatomic Physics Research
- Atomic and Molecular Physics
- Physics of Superconductivity and Magnetism
- Nuclear Engineering Thermal-Hydraulics
- Analytical Chemistry and Sensors
- Laser-induced spectroscopy and plasma
- GNSS positioning and interference
- Computational Fluid Dynamics and Aerodynamics
- High-Energy Particle Collisions Research
- Vehicle Dynamics and Control Systems
- Silicon and Solar Cell Technologies
KTH Royal Institute of Technology
2016-2025
University of Florence
2024
University of Rome Tor Vergata
2024
Max Planck Institute for Plasma Physics
2017-2021
Royal Military Academy
2020
Culham Science Centre
2011-2019
Czech Academy of Sciences, Institute of Plasma Physics
2019
University of York
2013-2019
Fusion (United States)
2019
Fusion Academy
2019
This paper reports the impact on confinement and power load of high-shape 2.5 MA ELMy H-mode scenario at JET a change from all carbon plasma-facing components to an metal wall. In preparation this change, systematic studies reduction as result fuelling in combination with nitrogen seeding were carried out JET-C are compared their counterpart metallic An unexpected significant is reported decrease pedestal but partially recovered injection nitrogen.
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 combined effect high rotational shear and low magnetic shear. The observations have important implications for understanding improved confinement advanced tokamak scenarios. Simulations using quasilinear fluid gyrofluid models show features mitigation, while nonlinear gyrokinetic simulations do not....
The original goals of the JET ITER-like wall included study impact an all W divertor on plasma operation (Coenen et al 2013 Nucl. Fusion 53 073043) and fuel retention (Brezinsek 083023). ITER has recently decided to install a full-tungsten (W) from start operations. One key inputs required in support this decision was possibility melting melt splashing during transients. Damage type can lead modifications surface topology which could higher disruption frequency or compromise subsequent...
Experimental evidence for the impact of a region high density localised in high-field side scrape-off layer (the HFSHD) on plasma confinement is shown various dedicated experiments ASDEX Upgrade (AUG). Increasing main ion fuelling to increase separatrix and shift profile outwards. Predictive pedestal modelling this indicates 25% decrease attainable top pressure, which compares well with experimental observations gas scan.
The replacement of the JET carbon wall (C-wall) by a Be/W ITER-like (ILW) has affected plasma energy confinement. To investigate this, experiments have been performed with both C-wall and ILW to vary heating power over wide range for plasmas different shapes.
Abstract The tokamak à configuration variable (TCV) continues to leverage its unique shaping capabilities, flexible heating systems and modern control system address critical issues in preparation for ITER a fusion power plant. For the 2019–20 campaign configurational flexibility has been enhanced with installation of removable divertor gas baffles, diagnostic capabilities an extensive set upgrades new dual frequency gyrotrons. baffles reduce coupling between main chamber allow detailed...
Abstract The JET hybrid scenario has been developed from low plasma current carbon wall discharges to the record-breaking Deuterium-Tritium plasmas obtained in 2021 with ITER-like Be/W wall. development started pure Deuterium refinement of current, and toroidal magnetic field choices succeeded solving heat load challenges arising 37 MW injected power ITER like environment, keeping radiation edge core controlled, avoiding MHD instabilities reaching high neutron rates. have re-run Tritium...
The instrument function of the high resolution Thomson scattering (HRTS) diagnostic in Joint European Torus (JET) has been calculated for use improved pedestal profile analysis. full width at half maximum (FWHM) spatial response is (22 ± 1) mm original HRTS system configuration and depends on particular magnetic topology JET plasmas. An improvement to optical design laser input presented. smearing across flux surfaces reduced this design. new implemented (from JPN 78742, July 2009)...
In both JET and ASDEX Upgrade (AUG) the plasma energy confinement has been affected by presence of a metal wall requirement increased gas-fuelling to avoid tungsten pollution plasma.In with beryllium/tungsten high triangularity baseline H-mode scenario (i.e.similar ITER reference scenario) strongest benefit shaping give good normalised H 98 ~1 at Greenwald density fraction f GW ~0.8 disappeared.In AUG full could be achieved in plasmas, albeit elevated pressure β N >2.The lost respect carbon...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation M. N. A. Beurskens, T. H. Osborne, P. Schneider, E. Wolfrum, L. Frassinetti, R. Groebner, Lomas, I. Nunes, S. Saarelma, Scannell, B. Snyder, D. Zarzoso, Balboa, Bray, Brix, J. Flanagan, C. Giroud, Giovannozzi, Kempenaars, Loarte, de la Luna, G. Maddison, F. Maggi, McDonald, Pasqualotto, Saibene, Sartori, Emilia...
Abstract New experiments in 2013–2014 have investigated the physics responsible for decrease H-mode pedestal confinement observed initial phase of JET-ILW operation (2012 Experimental Campaigns). The effects plasma triangularity, global beta and neutrals on stability been systematically. pedestals is analysed framework peeling–ballooning model assumptions predictive code EPED. Low D content plasma, achieved either by low 2 gas injection rates or divertor configurations with optimum pumping,...
In the recent JET experimental campaigns with new ITER-like wall (JET-ILW), major progress has been achieved in characterization and operation of H-mode regime metallic environments: (i) plasma breakdown at first attempt X-point L-mode recovered a few days operation; (ii) stationary stable type-I ELMy H-modes βN ∼ 1.4 have low high triangularity shape plasmas are showing that their operational domain H = 1 is significantly reduced JET-ILW mainly because need to inject large amount gas (above...
This paper reports the progress made at JET-ILW on integrating requirements of reference ITER baseline scenario with normalized confinement factor 1, a pressure 1.8 together partially detached divertor whilst maintaining these conditions over many energy times. The 2.5 MA high triangularity ELMy H-modes are studied two different configurations D-gas injection and nitrogen seeding. power load reduction N seeding is reported. relationship between an increase in pedestal investigated....
Type I ELMy H-mode operation in JET with the ITER-like Be/W wall (JET-ILW) generally occurs at lower pedestal pressures compared to those full carbon (JET-C). The density is similar but temperature where type ELMs occur reduced and below so-called critical I–type III transition reported JET-C experiments. Furthermore, confinement factor H98(y,2) baseline plasmas JET-ILW low power fractions Ploss/Pthr,08 < 2 (where Ploss (Pin − dW/dt), Pthr,08 L–H threshold from Martin et al 2008 (J. Phys....
The JET exploitation plan foresees D–T operations in 2020 (DTE2). With respect to the first campaign 1997 (DTE1), when was equipped with a carbon wall, experiments will be conducted presence of beryllium–tungsten ITER-like wall and benefit from an extended improved set diagnostics higher additional heating power (32 MW neutral beam injection + 8 ion cyclotron resonance heating). There are several challenges presented by new wall: general deterioration pedestal confinement; risk heavy...
The evolution of the JET high performance hybrid scenario, including central accumulation tungsten (W) impurity, is reproduced with predictive multi-channel integrated modelling over multiple confinement times using first-principle based core transport models.8 channels ( , ) are modelled predictively, self-consistent sources, radiation and magnetic equilibrium, yielding a system non-linearities: This can reproduce observed radiative temperature collapse after several times.W transported...
Abstract We present the results of GENE gyrokinetic calculations based on a series JET–ITER-like-wall (ILW) type I ELMy H-mode discharges operating with similar experimental inputs but at different levels power and gas fuelling. show that turbulence due to electron-temperature-gradient (ETGs) modes produces significant amount heat flux in four JET–ILW discharges, and, when combined neoclassical simulations, is able reproduce for two low pulses. The simulations plausibly high-gas fluxes as...
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 As part the DTE2 campaign in JET tokamak, we conducted a parameter scan T and D-T complementing existing pulses H D. For different main ion masses, type-I ELMy H-modes at fixed plasma current magnetic field can have pedestal pressure varying by factor of 4 total changing from <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>β</mml:mi> <mml:mrow> <mml:mi mathvariant="normal">N</mml:mi> </mml:mrow> </mml:msub> <mml:mo>=</mml:mo>...
Abstract Plasmas with negative triangularity (NT) shape have been recently shown to be able achieve H-mode levels of confinement in L-mode, avoiding detrimental edge localised modes. Therefore, this plasma geometry is now studied as a possible viable option for future fusion reactor. Within framework, an NT under investigation the full power scenario Divertor Tokamak Test (DTT) facility, construction Italy, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">...
Abstract ITER is of key importance in the European fusion roadmap as it aims to prove scientific and technological feasibility a future energy source. The EUROfusion consortium labs within Europe contributing preparation exploitation operation aspires exploit outcomes view DEMO. paper provides an overview major progress obtained recently, carried out frame new (initiated 2021) work-package called ‘ Pr eparation I TER O peration’ (PrIO). directly supported by eleven PrIO contributions given...
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.
To consolidate International Thermonuclear Experimental Reactor (ITER) design choices and prepare for its operation, Joint European Torus (JET) has implemented ITER's plasma facing materials, namely, Be the main wall W in divertor. In addition, protection systems, diagnostics, vertical stability control were upgraded heating capability of neutral beams was increased to over 30 MW. First results confirm expected benefits limitations all metal components (PFCs) but also yield understanding...
Experiments on JET with a carbon-fibre composite wall have explored the reduction of steady-state power load in an ELMy H-mode scenario at high Greenwald fraction ∼0.8, constant and close to L H transition. This paper reports systematic study due effect fuelling combination seeding over wide range pedestal density ((4–8) × 1019 m−3) detailed documentation divertor, main plasma conditions, as well comparative two extrinsic impurity nitrogen neon. It also impact overall behaviour, possible...