P. Carvalho
A5061065760- Magnetic confinement fusion research
- Fusion materials and technologies
- Superconducting Materials and Applications
- Nuclear Physics and Applications
- Laser-Plasma Interactions and Diagnostics
- Nuclear reactor physics and engineering
- Particle accelerators and beam dynamics
- Ionosphere and magnetosphere dynamics
- Atomic and Subatomic Physics Research
- Plasma Diagnostics and Applications
- Advanced Data Storage Technologies
- Geophysical Methods and Applications
- Seismic Imaging and Inversion Techniques
- Radiation Detection and Scintillator Technologies
- Advanced X-ray and CT Imaging
- Medical Imaging Techniques and Applications
- Solar and Space Plasma Dynamics
- Nuclear Materials and Properties
- Atomic and Molecular Physics
- High-Energy Particle Collisions Research
- Parallel Computing and Optimization Techniques
- Gaussian Processes and Bayesian Inference
- Geometric Analysis and Curvature Flows
- Statistical Methods and Bayesian Inference
- Spectroscopy Techniques in Biomedical and Chemical Research
University of Lisbon
2016-2025
Culham Science Centre
2016-2024
Culham Centre for Fusion Energy
2019-2024
United Kingdom Atomic Energy Authority
2019-2024
Instituto Politécnico da Guarda
2023-2024
Instituto Superior Técnico
2011-2023
Universidade Federal de Alagoas
2023
Instituto de Engenharia de Sistemas e Computadores Investigação e Desenvolvimento
2012-2023
United States Census Bureau
2023
Instituto Superior de Tecnologias Avançadas
2009-2021
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 next step in the Wendelstein stellarator line is large superconducting device 7-X, currently under construction Greifswald, Germany. Steady-state operation an intrinsic feature of stellarators, and one key element 7-X mission to demonstrate steady-state plasma conditions relevant for a fusion power plant. device, on hand, requires implementation special technologies, giving rise technical challenges during design, fabrication assembly such device. On other also physics development at...
Abstract A series of experiments have been executed at JET to assess the efficacy newly installed shattered pellet injection (SPI) system in mitigating effects disruptions. Issues, important for ITER disruption mitigation system, such as thermal load mitigation, avoidance runaway electron (RE) formation, radiation asymmetries during quench electromagnetic control and RE energy dissipation addressed over a large parameter range. The efficiency has examined various SPI strategies. paper...
Abstract In view of the future high power nuclear fusion experiments, early identification disruptions is a mandatory requirement, and presently main goal moving from disruption mitigation to avoidance control. this work, deep-convolutional neural network (CNN) proposed provide detection disruptive events at JET. The CNN ability learn relevant features, avoiding hand-engineered feature extraction, has been exploited extract spatiotemporal information 1D plasma profiles. model trained with...
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 In the paper we present an overview of interpretive modelling a database JET-ILW 2021 D-T discharges using TRANSP code. The main aim is to assess our capability computationally reproducing fusion performance various plasma scenarios different external heating and mixtures, understand driving mechanisms. We find that simulations confirm general power-law relationship between increasing power output, which supported by absolutely calibrated neutron yield measurements. A comparison...
Abstract We present an overview of results from a series L–H transition experiments undertaken at JET since the installation ITER-like-wall (JET-ILW), with beryllium wall tiles and tungsten divertor. Tritium, helium deuterium plasmas have been investigated. Initial in tritium show ohmic transitions low density power threshold for ( P LH ) is lower than ones densities, while we still lack contrasted data to provide scaling high densities. In there notable shift which minimum <?CDATA...
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 Precise values for radiated energy in tokamak disruption experiments are needed to validate mitigation techniques burning plasma tokamaks like ITER and SPARC. Control room analysis of power ( P rad ) on JET assumes axisymmetry, since fitting 3D radiation structures with limited bolometry coverage is an under-determined problem. In mitigated disruptions, toroidally asymmetric 3D, due fast-growing MHD modes localized impurity sources. To address this problem, Emis3D adopts a physics...
Abstract Experiments on ASDEX Upgrade (AUG) in 2021 and 2022 have addressed a number of critical issues for ITER EU DEMO. A major objective the AUG programme is to shed light underlying physics confinement, stability, plasma exhaust order allow reliable extrapolation results obtained present day machines these reactor-grade devices. Concerning pedestal physics, mitigation edge localised modes (ELMs) using resonant magnetic perturbations (RMPs) was found be consistent with reduction linear...
Abstract The pre-thermal quench (pre-TQ) dynamics of a pure deuterium ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi mathvariant="normal">D</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> </mml:math> ) shattered pellet injection (SPI) into <mml:mn>3</mml:mn> <mml:mstyle scriptlevel="0"/> <mml:mi>MA</mml:mi> / <mml:mn>7</mml:mn> <mml:mi>MJ</mml:mi> JET H-mode plasma is studied via 3D non-linear MHD modelling with the JOREK code....
The Alfvén instability nonlinearly excited the energetic-particle-driven geodesic acoustic mode on ASDEX-Upgrade tokamak, as demonstrated experimentally. mechanism of excitation and nonlinear evolution is not yet fully understood. In present work, a first-principles simulation using MEGA code investigated properties in both linear growth saturated phases. Here we show that successfully reproduced coexistence these two modes, agreed with experimental results well. Conclusive evidence showed...
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...
Abstract Deuterium (D) and beryllium (Be) fluxes are obtained in JET Low-confinement (L-mode) plasmas at the outer limiters of first wall using calibrated visible cameras. They inferred from measured radiances spectroscopic S/XB method. From fluxes, effective gross erosion yield Yeff limiter surface is estimated. After discussing uncertainties proposed methodology, we show dependence deduced particle recent L-mode on: separatrix-limiter clearance, magnetic field plasma current, NBI ICR...
The new JET ITER-like wall (made of beryllium and tungsten) is more fragile than the former carbon fiber composite requires active protection to prevent excessive heat loads on plasma facing components (PFC). Analog CCD cameras operating in near infrared wavelength are used measure surface temperature PFCs. Region interest (ROI) analysis performed real time maximum measured each ROI sent vessel thermal map. system started October 2011 has already successfully led a safe landing when hot...
Retrieving spatial distribution of plasma emissivity from line integrated measurements on tokamaks presents a challenging task due to ill-posedness the tomography problem and limited number lines sight. Modern methods therefore implement a-priori information as well constraints, in particular some form penalisation complexity. In this contribution, current under development (Tikhonov regularisation, Bayesian neural networks) are briefly explained taking into account their potential for...
Integrating the plasma core performance with an edge and scrape-off layer (SOL) that leads to tolerable heat particle loads on wall is a major challenge. The new European medium size tokamak task force (EU-MST) coordinates research ASDEX Upgrade (AUG), MAST TCV. This multi-machine approach within EU-MST, covering wide parameter range, instrumental progress in field, as ITER DEMO core/pedestal SOL parameters are not achievable simultaneously present day devices. A two prong adopted. On one...
The Multithreaded Application Real-Time executor (MARTe) is a data driven framework environment for the development and deployment of real-time control algorithms. main ideas which led to present version were standardize systems, while providing set strictly bounded standard interfaces outside world also accommodating collection facilities promote speed ease development, commissioning such systems. At core every MARTe based application, independent inter-communicating software blocks, named...
In present and future magnetic confined fusion devices with metallic plasma-facing components (PFCs) such as JET-ILW ITER, the calculation of plasma composition must account for multiple impurities a wide range mass charge, resolve their poloidal asymmetries different central peakings various elements. Single measurements radiation effective charge are not enough to characterize this complex system self-consistent analysis data from diagnostics is required. This contribution describes method...
Abstract An overview of recent results obtained at the tokamak ASDEX Upgrade (AUG) is given. A work flow for predictive profile modelling AUG discharges was established which able to reproduce experimental H-mode plasma profiles based on engineering parameters only. In center, theoretical predictions current redistribution by a dynamo effect were confirmed experimentally. For core transport, stabilizing fast ion distributions turbulent transport shown be important explain isotope and...
Abstract Disruption mitigation remains a critical, unresolved challenge for ITER. To aid in addressing this challenge, shattered pellet injection (SPI) system was installed on JET and experiments conducted at range of thermal energy fractions stored energies excess 7 MJ. The primary goals these were to investigate the efficacy SPI ability plasma assimilate multiple pellets. Single injections produced saturation total radiated ( W rad ) with increasing injected neon content, suggesting...