João P. S. Bizarro
A5016354776- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Fusion materials and technologies
- Laser-Plasma Interactions and Diagnostics
- Superconducting Materials and Applications
- Advanced Thermodynamics and Statistical Mechanics
- Particle accelerators and beam dynamics
- Plasma Diagnostics and Applications
- Nuclear reactor physics and engineering
- Solar and Space Plasma Dynamics
- Atomic and Molecular Physics
- Statistical Mechanics and Entropy
- Dust and Plasma Wave Phenomena
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum and electron transport phenomena
- thermodynamics and calorimetric analyses
- Machine Fault Diagnosis Techniques
- Physics of Superconductivity and Magnetism
- Fault Detection and Control Systems
- Quantum chaos and dynamical systems
- High-pressure geophysics and materials
- Quantum Mechanics and Applications
- Advanced Electrical Measurement Techniques
- stochastic dynamics and bifurcation
- Phase Equilibria and Thermodynamics
University of Lisbon
2010-2024
Instituto Politécnico de Lisboa
2013-2022
Royal Military Academy
2020
Instituto Superior Técnico
2005-2014
Instituto de Engenharia de Sistemas e Computadores Investigação e Desenvolvimento
1999-2014
Instituto Superior de Gestão
2008
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
1992-2005
CEA Cadarache
1992-2005
Abstract In 2021 JET exploited its unique capabilities to operate with T and D–T fuel an ITER-like Be/W wall (JET-ILW). This second major campaign (DTE2), after DTE1 in 1997, represented the culmination of a series enhancements—new fusion diagnostics, new injection capabilities, refurbishment plant, increased auxiliary heating, in-vessel calibration 14 MeV neutron yield monitors—as well as significant advances plasma theory modelling community. DTE2 was complemented by sequence isotope...
The 2014–2016 JET results are reviewed in the light of their significance for optimising ITER research plan active and non-active operation. More than 60 h plasma operation with first wall materials successfully took place since its installation 2011. New multi-machine scaling type I-ELM divertor energy flux density to is supported by principle modelling. relevant disruption experiments modelling reported a set three mitigation valves mimicking setup. Insights L–H power threshold Deuterium...
Abstract For the past several years, JET scientific programme (Pamela et al 2007 Fusion Eng. Des . 82 590) has been engaged in a multi-campaign effort, including experiments D, H and T, leading up to 2020 first with 50%/50% D–T mixtures since 1997 ever plasmas ITER mix of plasma-facing component materials. this purpose, concerted physics technology was launched view prepare campaign (DTE2). This paper addresses key elements developed by directly contributing preparation. intense preparation...
A 20 MW/5 GHz lower hybrid current drive (LHCD) system was initially due to be commissioned and used for the second mission of ITER, i.e. Q = 5 steady state target. Though not part currently planned procurement phase, it is now under consideration an earlier delivery. In this paper, both physics technology conceptual designs are reviewed. Furthermore, appropriate work plan also developed. This design, R&D, installation a MW LHCD on ITER follows Scientific Technical Advisory Committee...
A selection of achievements and first physics results are presented the European Integrated Tokamak Modelling Task Force (EFDA ITM-TF) simulation framework, which aims to provide a standardized platform an integrated modelling suite validated numerical codes for prediction complete plasma discharge arbitrary tokamak.The framework developed by ITM-TF, based on generic data structure including both simulated experimental data, allows development sophisticated simulations (workflows)...
The global energy confinement of combined ohmic and lower hybrid driven TORE SUPRA plasmas has been analysed at various densities. In contradiction to the L mode ITER scaling law, this analysis indicates that time depends strongly on plasma density. Furthermore, thermal electron content steady state discharges is found be in good agreement with Rebut-Lallia-Watkins (RLW) law. Current ramp experiments show an enhancement internal inductance, li. These results have extended regimes current...
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...
A comprehensive study is presented on the Weyl-Wigner formalism for rotation-angle and angular-momentum variables: elements of kinematics are extended, dynamics established, implications rotational perodicity quantization investigated. Particular attention paid to discreteness, two its consequences emphasized: importance evenness oddness, need use difference operators in a discrete domain, whereas one differential operator suffices continuous domain. These shown strongly distinguish...
The TORE SUPRA lower hybrid current drive experiments (8 MW/3.7 GHz) use large phased waveguide arrays, four rows of 32 active waveguides and two passive for each the grills, to couple waves plasma. These launchers are based on 'multijunction' principle which allows them be quite compact is therefore attractive design efficient multi-megawatt antennas in NET/ITER. Extensive coupling measurements have been performed order study radiofrequency (RF) characteristics plasma loaded antennas....
The "European Transport Simulator" (ETS) [1,2] is the new modular package for 1-D discharge evolution developed within EFDA Integrated Tokamak Modelling (ITM) Task Force.It consists of precompiled physics modules combined into a workflow through standardized input/output data-structures.Ultimately, ETS will allow an entire simulation from start up until current termination phase, including controllers and sub-systems.The paper presents status towards this ultimate goal.It discusses design...
Using a combined ray-tracing and Fokker–Planck code, comprehensive detailed analysis is presented on the importance of toroidally induced ray stochasticity for modeling lower-hybrid (LH) current drive in tokamaks dynamics launched power spectrum. The injected LH distribution poloidal angle parallel wave index accurately represented by taking into account extent antenna efficiently covering full range its radiated influence balance between damping exponential divergence nearby trajectories...
Detailed experimental studies of ion heat transport have been carried out in JET exploiting the upgrade active charge exchange spectroscopy and availability multi-frequency cyclotron resonance heating with 3He minority. The determination temperature gradient (ITG) threshold stiffness offers unique opportunities for validation well-established theory ITG driven modes. Ion is observed to decrease strongly presence toroidal rotation when magnetic shear sufficiently low. This effect dominant...
Abstract We derive, from first principles and using the Weyl–Wigner formalism, a fully quantum kinetic model describing dynamics in phase space of Dirac electrons single-layer graphene. In limit ℏ → 0, we recover well-known semiclassical Boltzmann equation, widely used graphene plasmonics. The polarizability function is calculated and, as benchmark, retrieve result based on random-phase approximation. By keeping all orders , use newly derived equation to construct fluid for macroscopic...
In view of high-power, long-pulse steady-state operation, Tore Supra has incorporated in its design the active control heat and particles a realistic environment. early experimental phase Supra, first generation plasma-facing components was tested, these tests provided much physics technological information illuminated various operational difficulties. particular, experiments revealed weakness graphite-to-metal brazing process originally adopted for actively cooled high-heat-flux components....
The presence of the work done against friction is incorporated into analysis efficiency heat engines based on first and second laws thermodynamics. We obtain efficiencies Stirling Brayton with recover results known from finite-time show that ηfric/η ≈ (1 − Wfric/W), where ratio without Wfric/W fraction W performed by working fluid which spent forces.
Using ray tracing, a detailed investigation of the lower-hybrid (LH) wave propagation in presence toroidal magnetic field ripple is presented. The local behavior first depicted for cylindrical equilibrium periodically modulated along axial direction. Variations trajectories component vector parallel to are observed, with maximum relative amplitude that locally order level. For full rippled equilibrium, similar found when trajectory crosses high region. Despite modest perturbation, its global...
Established expressions for entropy production in irreversible processes are generalized to include friction explicitly, as a source of irreversibility the interaction between system and its surroundings. The net amount heat delivered does not come now only from reservoir, but may have an additional component coming work done against forces dissipated heat. To avoid ambiguities interpreting different contributions increase, latter is also written terms directly exchanged surroundings...
For the first time, tokamak equilibria with negative toroidal current flowing in plasma core are computed consistently available measurements from typical current-hole discharges. The equilibrium reconstruction, which leads to non-nested configurations where a system of axisymmetric magnetic islands unfolds, yields an overall good agreement between and experimental plasma-pressure profiles, together excellent fit motional-Stark-effect data. Therefore, considering accuracy limits present-day...
The effect of plasma density on toroidal rotation was examined in ramp-up experiments at a current 1 MA and magnetic field 3.6 T Tore Supra ohmic discharges. Experimental measurements have shown that the amplitude is reduced all radii when increasing density, although it remains counter-current direction. Neoclassical predictions including ripple-induced friction are qualitative agreement with such observations. However, core (r/a < 0.5) accelerates nl ~ 3 × 1019 m−2 breaks again above 3.5...
A detailed investigation is presented on the ability of combined ray-tracing and Fokker–Planck calculations to predict hard x-ray (HXR) emission during lower-hybrid (LH) current drive in tokamaks when toroidally induced ray stochasticity important. large number rays used electron distribution function obtained by self-consistently iterating appropriate power deposition calculations. It shown that effects due radial diffusion suprathermal electrons radiation scattering inner wall can be...
The different forms of the Clausius inequality are generalized to explicitly include frictional work, which can be partly dissipated as heat in surroundings and thus contribute increase its entropy so, a cyclic process, net leaving with directly exchanged system is no longer constrained by second law nonpositive. Likewise, lower bound for system’s change an arbitrary transformation not now determined solely transferred from but smaller term given dissipation latter. A wide range applications...
Using a combined ray tracing and Fokker-Planck code, an investigation is made on the propagation absorption of launched power spectrum during lower hybrid (LH) current drive in tokamaks, situation where toroidally induced stochasticity important. Stochastic effects are correctly taken into account by large number rays. The influence balance between wave damping stochastic divergence nearby trajectories governing dynamics establishing characteristics LH deposition patterns illustrated. It...
Numerical Grad-Shafranov (GS) equilibria with negative current density in the plasma core are computed which do not impose any particularly chosen models for pressure and current-density profiles. This flexibility allows profiles to be tailored so that an island unfolds low-field side, even elongated plasmas, thus sustaining negative-current against outward forces. Among other topological results, reversed GS also shown necessarily non-nested, except cylindrical very special degenerate,...
In the 2006 experimental campaign, progress has been made on JET to operate non-inductive scenarios at higher applied powers (31 MW) and density (n(1) similar 4 x 10(19) m(-3)), with ITER-relevant safety factor (q(95) 5) plasma shaping, taking advantage of new divertor capabilities. The extrapolation performance using transport modelling benchmarked database indicates that foreseen power upgrade (similar 45 will allow development where bootstrap current is maximized together fusion yield...
We study twisted wave solutions in a magnetized plasma and provide wave-kinetic description of an arbitrary spectrum turbulence. first consider the paraxial equation describing beam propagating along direction with respect to static magnetic field. then discuss properties appropriate solutions, establish corresponding turbulence, valid quite general conditions. Finally, we example application, where two modes different topological charge interact each other exchange energy angular momentum...