E. de la Cal
A5003076029- Magnetic confinement fusion research
- Fusion materials and technologies
- Ionosphere and magnetosphere dynamics
- Laser-Plasma Interactions and Diagnostics
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
- Plasma Diagnostics and Applications
- Nuclear reactor physics and engineering
- Solar and Space Plasma Dynamics
- Laser-induced spectroscopy and plasma
- Nuclear Physics and Applications
- Nuclear Materials and Properties
- Ion-surface interactions and analysis
- Fluid Dynamics and Turbulent Flows
- Atomic and Molecular Physics
- Astro and Planetary Science
- Diamond and Carbon-based Materials Research
- Gamma-ray bursts and supernovae
- Plasma Applications and Diagnostics
- Infrared Target Detection Methodologies
- Advanced X-ray and CT Imaging
- Semiconductor materials and devices
- Atomic and Subatomic Physics Research
- Anodic Oxide Films and Nanostructures
- Astronomy and Astrophysical Research
Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas
1993-2024
Universidad Complutense de Madrid
2013-2024
Instituto Superior Técnico
2006
Princeton Plasma Physics Laboratory
2006
CEA Cadarache
1997-1998
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
1997-1998
Instituto de Ciencia de Materiales de Madrid
1990
Consejo Superior de Investigaciones Científicas
1990
Abstract Fusion energy research has in the past 40 years focused primarily on tokamak concept, but recent advances plasma theory and computational power have led to renewed interest stellarators. The largest most sophisticated stellarator world, Wendelstein 7-X (W7-X), just started operation, with aim show that earlier weaknesses of this concept been addressed successfully, intrinsic advantages persist, also at parameters approaching those a future fusion plant. Here we first physics...
Abstract We present recent highlights from the most operation phases of Wendelstein 7-X, advanced stellarator in world. Stable detachment with good particle exhaust, low impurity content, and energy confinement times exceeding 100 ms, have been maintained for tens seconds. Pellet fueling allows plasma reduced ion-temperature-gradient turbulence, during such phases, overall is so (energy often 200 ms) that attained density temperature profiles would not possible less optimized devices, since...
Abstract After the second Deuterium–Tritium Campaign (DTE2) in JET tokamak with ITER-Like Wall (ILW) and full tritium campaigns that preceded followed after DTE2, a sequence of fuel recovery methods was applied to promote removal from wall components. The started several days baking main chamber walls at 240 °C 320 °C. Subsequently, superimposed Ion-Cyclotron Conditioning (ICWC) Glow Discharge (GDC) cleaning cycles deuterium. Diverted plasma operation deuterium different strike point...
The first experimental campaign of the TJ-II stellarator has been conducted using electron cyclotron resonance heating (, ) with a pulse length . flexibility device used to study five different configurations varying plasma volume and rotational transform. In this paper, main results are presented and, in particular, influence plasma-wall interaction phenomena on confinement is briefly discussed.
This paper presents the latest results on confinement studies in TJ-II stellarator. The inherently strong plasma–wall interaction of has been successfully reduced after lithium coating by vacuum evaporation. Besides H retention and low Z , Li was chosen because there exists a reactor-oriented interest this element, thus giving special relevance to investigation its properties. Li-coating led important changes plasma performance. Particularly, effective density limit NBI plasmas extended...
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 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...
This paper presents an overview of experimental results and progress made in investigating density control using Li-coating, transport L–H transitions TJ-II. The Li-coating changes drastically the plasma–wall interaction, decreasing recycling, enlarges substantially operational range device delaying appearance radiative collapse that happens for higher densities, which permits confinement properties much denser plasmas to be studied. Moreover, mode transition has only been achieved after...
Abstract A sequence of fuel recovery methods was tested in JET, equipped with the ITER-like beryllium main chamber wall and tungsten divertor, to reduce plasma deuterium concentration less than 1% preparation for operation tritium. This also a key activity regard refining clean-up strategy be implemented at end 2nd DT campaign JET (DTE2) assess tools that are envisaged mitigate tritium inventory build-up ITER. The began 4 days baking 320 °C, followed by further which Ion Cyclotron Wall...
Four different tin-wetted, tungsten CPS (Capillary Porous System) targets where exposed to NBI pulses in the OLMAT High Heat flux (HHF) facility. They include two flexible ones placed on a TZM support (W meshes and W felt) compact (sintered disk 3D printed W). A comparative study was performed using fast-frame imaging camera an infrared pyrometer. Surface temperature increase homogeneity, particle ejection, damage overall behaviour were studied for each case. Sn drop/accumulation at lower...
Wall conditioning techniques based on radio frequency (RF) discharges in fusion devices with permanent magnetic field were developed a few years ago. The first experiments of RF plasma the ion cyclotron range called performed Tore Supra and Textor later also HT-7 W7-AS. A high efficiency terms hydrogen removal surface cleaning has been demonstrated. other alternative, electron frequencies conditioning, studied recent past. Besides cleaning, have applied to thin film deposition. We report...
This paper reports the impact of different confinement regimes on 2D structure edge turbulence. An image analysis method based two-dimensional continuous wavelet transformation is used to localize structures (blobs) in images and extract their geometrical characteristics (position, scale, orientation angle aspect ratio). We study shear-layers these aspects blobs. Results show a reduction angular dispersion blobs as shear layer established boundary, well an increase elongation structures....
Abstract TJ-II stellarator results on modelling and validation of plasma flow asymmetries due to on-surface potential variations, fuelling physics, Alfvén eigenmodes (AEs) control stability, the interplay between turbulence neoclassical (NC) mechanisms liquid metals are reported. Regarding neoclassically predicted asymmetries, its impact radial electric field along flux surface has been successfully validated against Doppler reflectometry measurements. Research physics core with pellets...
An intensified visible camera looks tangentially at a poloidal limiter where helium recycles, acting as wide neutral source, and the atomic line emission due to plasma excitation becomes strongly localized there. It includes bifurcated coherent bundle, each end with different interference filter select lines, so that two simultaneous filtered images are captured in one single frame. The object of proposed technique is apply well-known helium-beam line-ratio obtain from selected...
The dependence of impurity confinement time on the charge and mass ions injected from various samples (LiF, BN, W) by laser blow-off method is reported for electron cyclotron heated discharges TJ-II heliac. Distinct confinements are distinguished clearly these in plasma core as revealed soft x-ray analysis tomographic reconstruction bolometer array signals. A with seems to be most probable explanation, confirmed spectrally resolved data vacuum–ultraviolet range. This discussed terms...
Abstract The electron density n e of turbulent coherent structures (blobs) has been measured at the edge plasma TJ-II stellarator using helium line ratio technique. A spectroscopic high-speed camera set-up allowed 2D imaging with spatial resolutions a few millimetres and exposure times down to 15 µ s. have compared raw emission structures, which in principle should be similar due expected relation between both, although generally positive (negative) correspond blobs (holes), we see that...
The effects of 3D geometry are explored in TJ-II from two relevant points view: neoclassical transport and modification stability dispersion relation waves. Particle fuelling impurity studied considering the properties, paying attention to both other possible mechanisms. magnetic topology on stability, confinement Alfvén Eigenmodes properties also explored, showing possibility controlling modes by modifying configuration; onset similar geodesic acoustic driven fast electrons or ions; weak...
The magnetic well is the main stabilising mechanism in TJ-II stellarator, since this an almost shearless device. has capability of varying its configuration by changing currents coils, allowing one to change while keeping vacuum rotational transform profile constant, particular. This characteristic makes stellarator a suitable device study impact unfavourable conditions on plasma performance and stability. here reported experiments explored family ten configurations with similar well, from...