A5066963314- Magnetic confinement fusion research
- Fusion materials and technologies
- Ionosphere and magnetosphere dynamics
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Nuclear reactor physics and engineering
- Plasma Diagnostics and Applications
- Nuclear Materials and Properties
- Solar and Space Plasma Dynamics
- Dust and Plasma Wave Phenomena
- Nuclear Physics and Applications
- Particle Accelerators and Free-Electron Lasers
- High-Energy Particle Collisions Research
- Cold Fusion and Nuclear Reactions
- Physics of Superconductivity and Magnetism
- Advanced X-ray Imaging Techniques
- Fluid Dynamics and Turbulent Flows
- High-pressure geophysics and materials
- Atomic and Molecular Physics
- Quantum chaos and dynamical systems
- Integrated Energy Systems Optimization
- Plasma and Flow Control in Aerodynamics
- Gyrotron and Vacuum Electronics Research
- Atomic and Subatomic Physics Research
Tokamak Energy (United Kingdom)
2021-2025
University of Rome Tor Vergata
2013-2024
Chalmers University of Technology
1984-2024
Fusion Academy
1984-2023
Fusion (United States)
1984-2023
National Agency for New Technologies, Energy and Sustainable Economic Development
2002-2022
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
1980-2021
Royal Military Academy
2020
Culham Science Centre
2010-2019
Culham Centre for Fusion Energy
2007-2018
The stability of the ion temperature gradient modes is investigated using kinetic response without expansions in ωD/ω. A systematic parameter study carried out a low-beta circular flux surface equilibrium order to determine boundaries ηi vs εn space (ηi=d ln Ti/ d n, εn=Ln/R). Particular attention devoted consequences presence these for anomalous transport.
The behaviour of tungsten in the core hybrid scenario plasmas JET with ITER-like wall is analysed and modelled a combination neoclassical gyrokinetic codes. In these discharges, good confinement conditions can be maintained only for first 2?3?s high power phase. Later W accumulation regularly observed, often accompanied by onset magneto-hydrodynamical activity, particular tearing modes (NTMs), both which have detrimental effects on global energy confinement. dynamics process examined, taking...
The XGC1 edge gyrokinetic code is used for a high fidelity prediction the width of heat-flux to divertor plates in attached plasma condition. simulation results are validated against empirical scaling $\lambda_q \propto B_P^{-\gamma}$ obtained from present tokamak devices, where $\lambda_q$ mapped outboard midplane and $\gamma_q=1.19$ as defined by T. Eich et al. [Nucl. Fusion 53 (2013) 093031], $B_P$ magnitude poloidal magnetic field at separatrix surface. This predicts \leq 1mm$ when...
Abstract An overview is presented of the progress since 2021 in construction and scientific programme preparation Divertor Tokamak Test (DTT) facility. Licensing for building has been granted at end 2021. Cat. A radiologic source also 2022. The toroidal field magnet system progressing. prototype 170 GHz gyrotron produced it now under test on FALCON design vacuum vessel, poloidal coils civil infrastructures completed. shape first DTT divertor agreed with EUROfusion to different plasma exhaust...
Physics knowledge (theory and experiment) in energetic particles relevant to design of a reactor scale tokamak is reviewed, projections for ITER are provided this Chapter the Basis. The review includes single particle effects such as classical alpha heating toroidal field ripple loss, well collective instabilities that might be generated plasmas by particles. overall conclusion fusion expected provide an efficient plasma ignition sustained burn next step device. major concern localized heat...
We discuss the processes underlying excitation of fishbone-like internal kink instabilities driven by supra-thermal electrons generated experimentally different means: electron cyclotron resonance heating (ECRH) and lower hybrid (LH) power injection. The peculiarity interest exciting these fishbones ECRH only or LH is also analysed. Not mode stability explained, but transition between steady state nonlinear oscillations to bursting (almost regular) pulsations, as observed in FTU, interpreted...
The Hamiltonian picture of the free-electron laser (FEL) is reexamined and multielectron effects are accounted for. conditions under which multieleetron effect can be neglected made precise (low-gain regime) and, in this connection, strong signal analysis Stanford experiment carried out.
Following the completion in May 2011 of shutdown for installation beryllium wall and tungsten divertor, first set JET campaigns have addressed investigation retention properties development operational scenarios with new plasma-facing materials.The large reduction carbon content (more than a factor ten) led to much lower Z eff (1.2-1.4) during L-and H-mode plasmas, radiation burn-through phase plasma initiation consequence that breakdown failures are almost absent.Gas balance experiments...
Since the end of 2005 most plasma–wall interaction experiments on FTU have been focused possible use liquid lithium as plasma facing material. Liquid limiter is an active method to deposit, during discharge, a film walls with prolonged beneficial effects. Reliable operation very clean plasmas, low wall particle recycling, spontaneous peaking density profile for line-averaged values obtained. These results allowed us extend limit highest value so far obtained ( at I p = 0.7 MA and B T 7.1 T,...
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 soft X ray diagnostic at JET views the plasma from six directions with a total of 215 lines sight. good coverage makes it possible to make detailed tomographic reconstructions emission during various conditions. One tomography methods applied is discussed: grid based constrained optimization method that uses anisotropic smoothness on flux surfaces as regularization. This has made study in detail transport heavy trace impurities injected into by laser blow-off. Impurity injection...
The toroidal semicollisional microinstabilties driven by trapped electron dynamics and ion temperature gradients are analyzed using kinetic theory. Analytic dispersion relations derived discussed, with particular attention to the modeling of anomalous thermal conductivity. Relations previously models transport experimentally observed trends global energy confinement time also discussed.
The internal kink mode is destabilized by trapped high-energy particles, leading to a new branch of the dispersion relation with real frequency near average trapped-particle precession and growth rate same magnitude. This particle investigated numerically for variety distributions. Mode found as function plasma β, density, energy distribution. sources considered are neutral beam injection, ion-cyclotron heating, fusion alpha particles. Relevance various heating schemes discussed.
It is shown that a population of high-energy trapped particles, such as produced by ion cyclotron heating in tokamaks, can result plasma completely stable to both sawtooth oscillations and the fishbone mode. The window operation increases size with temperature trapped-particle energy, provides means obtaining high current $\ensuremath{\beta}$.
A model is proposed to explain the behavior of gross energy confinement time in ohmically heated tokamak plasmas.The analysis takes into account effect anomalous thermal conductivity due small scale turbulence and macroscopic MHD behavior, which provides some constraints on temperature profile.Results indicate that associated with dissipative trapped-electron mode ion gradient (tij) can account, respectively, for Neo-Alcator scaling saturation density.Comparisons experimental results show...
Since the installation of an ITER-like wall, JET programme has focused on consolidation ITER design choices and preparation for operation, with a specific emphasis given to bulk tungsten melt experiment, which been crucial final decision material choice day-one divertor in ITER. Integrated scenarios have progressed re-establishment long-pulse, high-confinement H-modes by optimizing magnetic configuration use ICRH avoid impurity accumulation. Stationary discharges detached conditions small...
A pedestal prediction model Europed is built on the existing EPED1 by coupling it with core transport simulation using a Bohm-gyroBohm to self-consistently predict JET-ILW power scan for hybrid plasmas that display weaker degradation than IPB98(y, 2) scaling of energy confinement time. The weak reproduced in coupled core-pedestal simulation. further tested 3.0 MA plasma highest stored achieved so far, giving within error margins measured experimental value. density based neutral penetration...
A technique, volumetric power optimization, is presented for enhancing the output of magnetic confinement fusion devices. Applied to a tokamak, this approach involves shifting burning plasma region larger volume while introducing minimal perturbations boundary shape. This edge perturbation—squareness—is analogous pinching and stretching boundary. Stability calculations confirm that alteration compatible with maintaining stability. optimization method optimizing could improve performance...
A comprehensive stability analysis of the ion-temperature-gradient-driven mode in various parameter domains is presented. The effect parallel ion dynamics on threshold value toroidal geometry investigated for short-wavelength and finite-shear limits. general explicit expression given, which agreement with results obtained by solving full integrodifferential equation. destabilizing trapped electrons below qualitatively similar to local theory, but electron collisionality has be sufficiently...
Understanding and modelling turbulent transport in thermonuclear fusion plasmas are crucial for designing optimizing the operational scenarios of future reactors. In this context, exhibiting state transitions, such as formation an internal barrier (ITB), particularly interesting since they can shed light on physics offer opportunity to test different turbulence suppression models. paper, we focus ITB Joint European Torus (JET) [1] hybrid-scenario plasmas, where, due monotonic safety factor...