A5101550886- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- earthquake and tectonic studies
- Geological and Geochemical Analysis
- Fusion materials and technologies
- Laser-Plasma Interactions and Diagnostics
- Solar and Space Plasma Dynamics
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
- High-pressure geophysics and materials
- Geological and Tectonic Studies in Latin America
- Earthquake Detection and Analysis
- Geological and Geophysical Studies Worldwide
- Plasma Diagnostics and Applications
- Landslides and related hazards
- Seismology and Earthquake Studies
- Ocean Waves and Remote Sensing
- Geology and Paleoclimatology Research
- Advanced Fiber Optic Sensors
- Laser Material Processing Techniques
- Anomaly Detection Techniques and Applications
- Nuclear Physics and Applications
- Meteorological Phenomena and Simulations
- Seismic Imaging and Inversion Techniques
- Surface Roughness and Optical Measurements
Université Gustave Eiffel
2023-2025
Université Grenoble Alpes
2023-2025
Institut des Sciences de la Terre
2023-2025
Université Savoie Mont Blanc
2025
Institut de Recherche pour le Développement
2025
Centre National de la Recherche Scientifique
2025
University of Concepción
2019-2023
Autonomous University of Chiapas
2023
Friedrich Schiller University Jena
2023
Helmholtz Institute Jena
2023
Abstract We present a formal seismic segmentation model of the Chile Margin derived from multivariate analysis gravity anomalies, basal friction and interplate locking GPS velocities. These independent proxies frictional structure along megathrust integrate over timescales 10 1 –10 7 years. analyze their covariance using Principal Component Analysis (PCA) extracting Empirical Orthogonal Functions (EOFs) Components (PCs). find that (a) first + second PCA modes for triple combination explain...
In a tokamak plasma, sawtooth oscillations in the central temperature, caused by magnetohydrodynamic instability, can be partially stabilized fast ions. The resulting less frequent crashes trigger unwanted activity. This Letter reports on experiments showing that modest electron-cyclotron current drive power, with deposition positioned feedback control of injection angle, reliably shorten period presence ions energies $\ensuremath{\ge}0.5\text{ }\text{ }\mathrm{MeV}$. Certain surprising...
Ion temperature gradient (ITG) and trapped electron modes (TEM) are two important micro-instabilities in the plasma core region of fusion devices (). They usually coexist same range spatial scale (around ), which makes their discrimination difficult. To investigate them, one can perform gyrokinetic simulations, transport analysis phase velocity estimations. In Tore Supra, identification is made possible due to measured frequency fluctuation spectra. Indeed, turbulent spectra generally...
The Atacama segment in Northern Chile (24{\deg}S to 31{\deg}S) is a mature seismic gap with no major event (Mw>8) since 1922. In addition regular seismicity, around the subducting Copiap\'o ridge, region hosts swarms, and shallow deep slow slip events. To characterize fine structure of this its seismic-aseismic interplay, we instrumented almost 200 geodetic stations. Using machine learning, derived dense, high-resolution seismicity catalog, encompassing over 165,000 events double-difference...
To become very large earthquakes, seismic ruptures that saturate the seismogenic width (M>8.3 in subduction zones) need to propagate long distances along-strike. Multiple factors can hinder this propagation, among them available energy on fault. A recent extension of Linear Elastic Fracture Mechanics theory elongated provides a framework estimate when portion fault has enough potential energy, and is hence sufficiently loaded, generate earthquake. Based framework, we present method takes...
The Atacama segment in Northern Chile (24⁰S to 31⁰S) is a mature seismic gap with no major event (Mw≥8) since 1922. Nonetheless, the region regularly releases stress through shallow and deep slow slip events, hosts recurring swarm activity. To investigate this its complex seismic-aseismic behaviour, we instrumented almost 200 geodetic stations between November 2020 February 2024. Using machine learning techniques, derived dense, high-resolution seismicity...
Understanding the inner structure of crust and upper mantle is essential to evaluate those mechanisms driving Earth’s dynamics. Usually, surface deformation provides valuable constraints on viscoelastic parameters.  Postseismic following large megathrust earthquakes, offers a unique opportunity explore properties shallower earth since it strongly influenced by relaxation processes. This postseismic often recorded GNSS stations, which offer high temporal resolution...
Abstract Like earthquakes, slow slip events release elastic energy stored on faults. Yet, the mechanisms behind instability and its relationship with seismicity are debated. Here, we use a seismo‐geodetic deployment to document shallow event (SSE) in 2023 Chile subduction. We observe dense, migrating seismic swarms accompanying SSE, comprised of interface activity upper plate splay faulting. Our observations suggest that initiation is driven by structurally confined fluid overpressure...
In order to study the temporal dynamics of turbulence, sweep time our reflectometry has been shortened from 20 2 μs with 1 dead time. Detailed technical aspects upgrade are given, namely, about stability ramp generation, detection setup, and fast acquisition module. A review studies (velocity measurement modifications wavenumber spectrum, radial mapping correlation time, etc.) offered by such improvements is presented.
A 32-channel, 1GHz spaced heterodyne radiometer is used on the Tore Supra tokamak to measure electron cyclotron emission (ECE) in frequency range 78–110GHz for ordinary mode (O:E‖B,k⊥B) and 94–126GHz extraordinary (X:E⊥B,k⊥B). The radial resolution essentially limited by ECE relativistic effects, depending temperature density, not channels’ spacing. time depends acquisition scheme: system allows both 1ms 10μs acquisition. For example, this leads precise mapping during MHD activity. First...
MHD instabilities driven by fast electrons identified as fishbonelike modes have been detected on Tore Supra during lower hybrid current drive discharges. Direct experimental evidence is reported of a novel feature: the regular redistribution suprathermal toward external tokamak regions which are correlated to periodic mode frequency jumps. Sharp drops electron temperature time trace factually linked cyclical deterioration confinement.
Abstract For a comprehensive comparison with theoretical models and advanced numerical turbulence simulations, large spectrum of fluctuation parameters was measured on the devices ASDEX Upgrade, TCV, Tore-Supra. Radial profiles scale-resolved levels in H-mode discharges are compared GENE simulations transition range from ion-temperature-gradient to trapped-electron-mode turbulence. Correlation reflectometry is used study microscopic structure GAMs where poloidal flow damping varied by means...
Closed loop control of the period fast ion stabilized sawtooth has been demonstrated for first time on Tore Supra by varying electron cyclotron current drive (ECCD) injection angles in real time. Fast ions generated up to 4 MW central resonance heating (ICRH) increased from ohmic value 25 ms 60 100 ms. This was reduced 30 addition only 300 kW ECCD. In ICRH heated shots where normalized minor radius ECCD absorption location swept 0.4 0.05 s, showed an abrupt change 70 when deposition reached...
Frequency swept reflectometry has reached the symbolic value of 1 μs sweeping time; this performance been made possible, thanks to an improved control ramp voltage driving frequency source. In parallel, memory depth acquisition system upgraded and can provide up 200 000 signals during a plasma discharge. Additional improvements regarding trigger delay determination linearity required by ultra-fast technique have set. While diagnostic is traditionally dedicated electron density profile...
In the Tore Supra tokamak, magnetohydrodynamic instabilities can be destabilized by energetic particles produced radio-frequency heating systems. This paper reports on experimental observations of two types particle driven internal modes: electron fishbone and beta-induced Alfven eigenmodes (BAEs). The evolutions these modes in frequency radial position during core relaxation cycles were determined their induced electronic temperature density fluctuations. Electron fishbones observed...
High frequency (> 100 kHz) modes have been observed for the first time in combined LHCD and ICR-heated minority H (D) plasmas on Tore Supra by means of a correlation ECE diagnostic fluctuation reflectometers. These identified as toroidicity-induced Alfven eigenmodes (TAEs) that are destabilized fast hydrogen ions with energies above 250 keV. In reversed central shear non-linear oscillations temperature, evolution TAE is linked to development local safety factor. This confirms temperature...
The ultra-fast swept reflectometer with the sweep time of 1 μs, inferior to characteristic turbulent scale, has provided measurements fast density and fluctuation evolution across major parts tokamak plasma radius. L-H transitions in a series discharges ASDEX Upgrade have been studied high temporal resolution. comparison behaviour L- H-mode is presented. I-phase oscillation dynamics described terms level, radial electric field normalised electron pressure gradient. Indications for phase...
Real-time control is essential for many aspects of tokamak operation. A key parameter to the current profile, since both confinement properties and magneto-hydrodynamic (MHD) activity depend on it in quite a sensitive way. The long pulse capability Tore Supra has allowed unique type experiment, where successive stationary states safety factor defined by their MHD activity, are established controlled real time. Multiple target could be requested reached during main heating phase single plasma...
Abstract Megathrust earthquakes are commonly accompanied by increased upper‐plate seismicity and occasionally triggered fault slip. In Chile, crustal faults slipped during after the 2010 Maule (M8.8) earthquake. We studied El Yolki (EYOF), a transtensional structure midways rupture not in 2010. mapped Holocene coastal plain using light detection ranging, which did reveal surface ruptures. However, inner‐edge shoreline angles along as well 4.3‐ to 4.0‐ka intertidal sediments back‐tilted on...
Measurements of electron temperature fluctuations by means correlation cyclotron emission (ECE) diagnostics aid in understanding the nature turbulent transport fusion plasmas. On Tore Supra tokamak, a 32-channel heterodyne ECE radiometer has been upgraded to include two channels for fluctuation measurements. The central frequency yttrium iron garnet filter on each channel is remotely monitored driver, allowing one shift observation volume plasma radially. To resolve amplitude 0.1%,...
Low-frequency (5- to 20-kHz) and high-frequency (40- 200-kHz) modes are studied during radio-frequency heating experiments on the Tore Supra tokamak by means of correlation electron cyclotron emission. High-frequency detected when plasma is heated ion range frequency waves in minority D(H) scheme combination with lower hybrid current drive (LHCD) producing a flat or slightly reversed q-profile. They identified as Alfvén cascade modes. When this mode triggered, fast losses (<20%) from neutron...
Great subduction earthquakes rupture similar regions of the megathrust during successive events separated by centuries. Mapping these (asperities) and their boundaries (barriers) is important for our understanding processes controlling segmentation seismic hazard assessment. We present a formal model Chile Margin derived from multivariate analysis gravity anomalies, basal friction critical taper interplate locking GPS velocities. These proxies integrate over timescales 10 to years we analyze...