A5114374767- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Fusion materials and technologies
- Superconducting Materials and Applications
- Laser-Plasma Interactions and Diagnostics
- Solar and Space Plasma Dynamics
- Nuclear reactor physics and engineering
- Social Robot Interaction and HRI
- Particle accelerators and beam dynamics
- Plasma Diagnostics and Applications
- Flow Experience in Various Fields
- Robotic Path Planning Algorithms
- Fluid Dynamics and Turbulent Flows
- Educational Games and Gamification
- Robotics and Automated Systems
- Nuclear Physics and Applications
- Laser-Matter Interactions and Applications
- Power System Optimization and Stability
- Tropical and Extratropical Cyclones Research
- Interactive and Immersive Displays
- Muon and positron interactions and applications
- Human Pose and Action Recognition
- Lattice Boltzmann Simulation Studies
- Sports Performance and Training
- AI in Service Interactions
University of Lisbon
2016-2025
CEA Cadarache
2024
Culham Centre for Fusion Energy
2016-2024
Culham Science Centre
2016-2024
Instituto de Engenharia de Sistemas e Computadores Investigação e Desenvolvimento
2012-2023
Instituto Superior Técnico
2005-2023
Royal Military Academy
2020
University of California, Irvine
2019
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2016
YDreams (Portugal)
2013-2014
Remarkable progress has been made in diagnosing energetic particle instabilities on presentday machines and establishing a theoretical framework for describing them.This overview describes the much improved diagnostics of Alfvén modelling tools developed world-wide, discusses interpreting observed phenomena.A multi-machine comparison is presented giving information performance both different plasma conditions outlining expectations ITER based our present knowledge.
This paper summarizes the physical principles behind novel three-ion scenarios using radio frequency waves in ion cyclotron range of frequencies (ICRF). We discuss how to transform mode conversion electron heating into a new flexible ICRF technique for and fast-ion generation multi-ion species plasmas. The theoretical section provides practical recipes selecting plasma composition realize scenarios, including two equivalent possibilities choice resonant absorbers that have been identified....
Alfvén waves are electromagnetic perturbations inherent to magnetized plasmas that can be driven unstable by a free energy associated with gradients in the energetic particles' distribution function. The particles velocities comparable velocity may excite instabilities via resonant wave–particle and momentum exchange. Burning large population of fusion born super-Alfvénic alpha magnetically confined devices prone weakly-damped eigenmodes (AEs) that, if allowed grow unabated, cause...
Dedicated experiments to generate energetic D ions and fusion-born alpha particles were performed at the Joint European Torus (JET) with ITER-like wall (ILW). Using 3-ion radio frequency (RF) heating scenario, deuterium from neutral beam injection (NBI) accelerated in core of mixed plasmas higher energies ion cyclotron resonance (ICRF) waves, turn leading a core-localized source particles. The fast-ion distribution RF-accelerated D-NBI was controlled by varying ICRF NBI power ( 4–6 MW, 3–20...
Abstract A toroidal Alfvén eigenmode (TAE) has been observed to be driven by alpha particles in a JET deuterium-tritium internal transport barrier plasma. The observation occurred 50 ms after the removal of neutral beam heating (NBI). mode is on magnetics, soft-xray, interferometry and reflectometry measurements. We present detailed stability calculations using similar tool set validated during deuterium only discharges. These strongly support conclusion that TAE, this was destabilized...
In DT plasmas, toroidal Alfvén eigenmodes (TAEs) can be made unstable by the alpha particles resulting from fusion reactions, and may induce a significant redistribution of fast ions. Recent experiments have been conducted in JET deuterium plasmas order to prepare scenarios aimed at observing alpha-driven TAEs future campaign. Discharges low density, large core temperatures associated with presence internal transport barriers characterised good energetic ion confinement performed. ICRH has...
Dedicated experiments were conducted in mixed H-D plasmas JET to demonstrate the efficiency of 3-ion ICRF scheme for plasma heating, relying on injected fast NBI ions as resonant ion species.Strong core localization RF power deposition close vicinity ion-ion hybrid layer was achieved, resulting an efficient generation energetic D ions, strong enhancement neutron rate and observation Alfvénic modes.A consistent physical picture that emerged from a range fast-ion measurements at JET, including...
This paper presents recent results on fast ion studies JET. A set of diagnostics for both confined and lost ions was employed investigating the response to MHD modes studying their behaviour in plasmas with toroidal field ripple shear-reversed plasmas. dependence losses mode amplitude deduced from experimental data. study various plasma scenarios has shown that a significant redistribution happens during changes profile safety factor monotonic. Significant ICRH accelerated protons were found...
Dedicated studies performed for toroidal Alfvén eigenmodes (TAEs) in ASDEX-Upgrade (AUG) discharges with monotonic q-profiles have shown that electron cyclotron resonance heating (ECRH) can make TAEs more unstable. In these AUG discharges, energetic ions driving were obtained by ion (ICRH). It was found off-axis ECRH facilitated TAE instability, appearing and disappearing on timescales of a few milliseconds when the power switched off. On-axis had much weaker effect TAEs, co- counter-current...
A systematic approach to evaluate the linear stability of Alfvén eigenmodes in presence fusion-born -particles is reported. The techniques developed are particularly useful when dealing with scenarios where no experimental guidance available about which more easily destabilized by supra-thermal population. advantages and limitations underlying model chosen describe wave-particle interaction discussed, along parallelization designed workflow order take advantage massively parallel computer...
Abstract Dedicated experiments were performed in JET DTE2 plasmas for obtaining an α -particle bump-on-tail (BOT) distribution aiming at exciting Alfvén eigenmodes (AEs). Neutral beam injection-only heating with modulated power was used so that fusion-born -particles the only ions present MeV energy range these DT plasmas. The modulation on a time scale shorter than slowing down chosen modulating source and thus sustaining BOT distribution. High-frequency modes toroidicity-induced Alfven...
Abstract In this work, we use reduced and perturbative models to examine the stability of toroidal Alfvén eigenmodes (TAEs) during internal transport barrier (ITB) afterglow in JET experiments designed for observation alpha driven TAEs. We demonstrate that JET-like conditions, it is sufficient an incompressible cold plasma model TAE reproduce experimental adiabatic features such as frequency position. When ion cyclotron resonant heating (ICRH) used destabilize TAEs, core-localised modes are...
In Joint European Torus (JET) [P. J. Lomas, Plasma Phys. Controled Fusion 31, 1481 (1989)], discharges with ion cyclotron resonance heating only, low-density plasmas and high fast ions energy contents provided a scenario where fishbones behavior has been observed to be related sawtooth activity: Crashes of monster sawteeth abruptly changed the type from low-frequency [B. Coppi F. Porcelli, Rev. Lett. 57, 2272 (1986)] high-frequency [L. Chen, R. White, M. Rosenbluth, 52, 1122 (1984)]. During...
In preparation for next step burning plasma devices such as ITER, experimental studies of instabilities and confinement energetic ions were performed on Joint European Torus (JET) Mega-Amper Spherical Tokamak (MAST) with innovative diagnostic techniques, in conventional shear-reversed plasmas, exploring a wide range effects ions. A compendium recent results testing capabilities the present-day facilities relevant study is presented this paper. 'Alpha tail' production using 3rd harmonic...
This video details the development of an intelligent outdoor Guide robot. The main objective is to deploy innovative robotic guide which not only able show information, but react affective states users, and offer location-based services using augmented reality. scientific challenges concern autonomous navigation localization, robust 24/7 operation, interaction with visitors through human facial feature detection as well engaging interactive behaviors in ongoing non-verbal dialogue user.
A hybrid magnetohydrodynamic (MHD)-gyro-kinetic model CASTOR-K developed for the study of Alfvén eigenmode (AE) stability in presence energetic ions has been applied to interpretation recent measurements waves JET. These include detailed AE damping performed using antenna excitation system and also observations cascades strongly reversed shear scenarios at The mode conversion between AEs kinetic relation continuum is studied calculated compared with experimental data. contribution ion...
ICRF heating at the fundamental cyclotron frequency of a hydrogen minority ion species also gives rise to partial power absorption by deuterium ions their second harmonic resonance. This paper studies distributions resulting from such 2nd JET using neutron emission spectroscopy data time flight spectrometer TOFOR. The fast are obtained over energy range 100 keV 2 MeV. Specifically, we study how vary as is used alone well in combination with NBI heating.
Abstract Dedicated fast ion D–D and D– 3 He fusion experiments were performed on JET with carbon wall (2008) ITER-like (2014) for testing the upgraded neutron energetic diagnostics of products. Energy spectrum neutrons was focus studies in pure deuterium plasmas. A significant broadening energy born observed, dependence maximum D energies plasma density established. Diagnostics charged products aneutronic reactions, 3.7 MeV alpha-particles similar to those D–T fusion, 14.6 protons,...
Abstract The linear stability of Alfvén eigenmodes in the presence fusion-born alpha particles is thoroughly assessed for two variants an ITER baseline scenario, which differ significantly their core and pedestal temperatures. A systematic approach based on CASTOR-K (Borba Kerner 1999 J. Comput. Phys . 153 101; Nabais et al 2015 Plasma Sci. Technol 17 89) used that considers all possible a given magnetic equilibrium determines growth rates due to alpha-particle drive Landau damping fuel...
Abstract Various types of Alfvén eigenmodes (AEs) have been destabilized by fast ions over a broad frequency range from ∼80 kHz to ∼700 in series JET experiments mixed D– 3 He plasmas heated with the three-ion ICRF scenario (2020 Nocente et al Nucl. Fusion 60 124006). In this paper, we identify radial localization AEs using an X-mode reflectometer, multiline interferometer and soft x-ray diagnostics. The analysis is focused on most representative example these measurements pulse #95691,...
The instabilities responsible for ion cyclotron resonance heating (ICRH) accelerated fast losses in plasmas with monotonic profile of the safety factor and long period sawteeth, as well range energies at which occur, were identified on JET tokamak. temporal evolution resolution energy pitch angle was measured using scintillator probe, allows us to determine orbits ions that reach detector. On other hand, Alfvénic CASTOR-K code, so it is possible identify collected Two different phases...
In this paper we discuss how the EMOTE project will design, develop and evaluate a new generation of artificial embodied tutors that have perceptive capabilities to engage in empathic interactions with learners shared physical space.