A5016115620- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Ionosphere and magnetosphere dynamics
- Fusion materials and technologies
- Superconducting Materials and Applications
- Plasma Diagnostics and Applications
- Laser-Plasma Interactions and Diagnostics
- Solar and Space Plasma Dynamics
- Geophysical Methods and Applications
- Gyrotron and Vacuum Electronics Research
- Atomic and Molecular Physics
- Antenna Design and Analysis
- Advanced Antenna and Metasurface Technologies
- Innovations in Aquaponics and Hydroponics Systems
- Advanced Sensor Technologies Research
- Nuclear Physics and Applications
- Fluid Dynamics and Turbulent Flows
- Nuclear physics research studies
- Quantum Chromodynamics and Particle Interactions
- Silicon Carbide Semiconductor Technologies
- Rabbits: Nutrition, Reproduction, Health
- Flow Measurement and Analysis
- Electromagnetic Compatibility and Measurements
- Agronomic Practices and Intercropping Systems
- Oceanographic and Atmospheric Processes
Autonomous University of Queretaro
2023-2024
Royal Military Academy
2007-2023
Max Planck Institute for Plasma Physics
2017-2023
Stellenbosch University
2020
South African Reserve Bank
2020
University of Limpopo
2020
Council for Scientific and Industrial Research
2015-2019
Max Planck Society
2017-2018
Plasma (Russia)
2015
Ghent University Hospital
2010-2012
Experiments in the tokamaks TEXTOR, CASTOR, T-10 and ISTTOK, as well reversed field pinch RFX have provided new complementary evidence on physics of universal mechanism E×B velocity shear stabilization turbulence, concomitant transport barrier formation radial conductivity by using various edge biasing techniques.
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....
Dedicated experiments have been carried out at the TEXTOR tokamak in biasing-induced improved confinement regimes using Langmuir probe and GPI measurements. The results show first evidence for intimate interaction among sheared flows, eddy structures, Reynolds stress, zonal ambient fluctuations during a transition to an confinement. flows impose dynamic effects on turbulence resulting generation of stress eventually suppression background fluctuation levels via nonlinear energy transfer...
Systematic measurements on the edge turbulence and turbulent transport have been made by Langmuir probe arrays TEXTOR under various static Dynamic Ergodic Divertor (DED) configurations. Common features are observed. With DED, in ergodic zone local flux reverses sign from radially outwards to inwards. The properties profoundly modified energy redistribution frequency spectra suppression of large scale eddies. fluctuation poloidal phase velocity changes direction electron ion diamagnetic...
The mechanism governing the impact of mass isotope on plasma confinement is still one main scientific conundrums facing magnetic fusion community after more than thirty years intense research. We have investigated properties local turbulence and long-range correlations in hydrogen deuterium plasmas TEXTOR tokamak. Experimental findings shown a systematic increasing amplitude during transition from to dominated plasmas. These results provide first direct experimental evidence importance...
The amount of genetic diversity in a population is determined by demographic and selection events its history. Human populations which exhibit greatly reduced overall diversity, presumably resulting from severe bottlenecks or founder events, are particularly interesting, not least because their potential to serve as valuable resources for health studies. Here, we present an unexpected case, the human Nias Island Indonesia, that exhibits severely Y chromosome (non-recombining portion [NRY])...
The current status of the mechanical and electromagnetic design for ICRF antenna system W7-X is presented. Two plugins are discussed: one consisting a pair straps with pre-matching to cover first frequency band, 25–38 MHz, second two short strap triplets band around 76 MHz. This paper focusses on lower band. Power coupling reference plasma profile studied help codes TOPICA Microwave Studio that deliver scattering matrix needed optimization geometric parameters box. Radiation power spectra...
The influence of the magnetic ergodization on edge turbulence and turbulence-induced transport has been investigated by Langmuir probes in TEXTOR under three different static DED configurations. Common features are observed. With DED, equilibrium profiles altered resultant positive Er is agreement with modelling. In ergodic zone, potential fluctuations strongly reduced local turbulent flux changes direction from radially outwards to inwards. same properties profoundly modified energy...
Experiments to investigate transport properties under the influence of dynamic ergodic divertor (DED) on TEXTOR are discussed. Relativistic runaway electrons applied for studying ergodization such as enhanced loss. The causes an loss rate; this is higher low relativistic than highly ones, in good agreement with particle orbit mapping. Edge can be controlled by DED perturbation: limiter H-mode plasmas ELM-like and heat bursts associated formation edge pressure gradients mitigated 6/2...
The electrostatic potential and density fluctuations have been measured at the edge of TEXTOR tokamak by two toroidally distant Langmuir probe arrays.The geodesic acoustic mode (GAM) zonal flows are observed in with a toroidal poloidal symmetric structure.The GAM frequency, , changes monotonically local temperature is close to frequency-dispersion predicted theories.Bispectral analysis shows clear nonlinear coupling between broadband ambient turbulence.The packet has narrow radial extent ≃...
Abstract In this letter, we present direct evidence of eddy breaking and tilting events observed at the edge TEXTOR tokamak using a 2D gas puff imaging diagnostic. The occurrence depends on magnitude E r × B flow shearing rate. results confirm theoretical predictions about influence sheared flows in splitting turbulence eddies, consequently, reducing turbulent transport.
Gas puff imaging (GPI) [S. J. Zweben, D. P. Stotler et al., Phys. Plasmas 9, 1981 (2002); R. Maqueda, G. A. Wurden Rev. Sci. Instrum. 74, 2020 (2003)] is a powerful diagnostic that permits two-dimensional measurement of turbulence in the edge region fusion plasma and based on observation local emission neutral gas, actively puffed into periphery plasma. The developed in-vessel GPI telescope observes from gas along (at puff) magnetic field lines. specially designed to operate severe TEXTOR...
The Toroidal Magnetized System device has been significantly upgraded to enable development of various wall conditioning techniques, including methods based on ion and electron cyclotron (IC/EC) range frequency plasmas, complement plasma–wall interaction research in tokamaks stellarators. toroidal magnetic field generated by 16 coils can reach its maximum 125 mT the axis. EC system is operated at 2.45 GHz with up 6 kW forward power. IC couple 10 MHz–50 MHz. direct current glow discharge a...
We show that it is possible to measure the parallel and perpendicular flow in a strongly magnetized plasma, using probe with two current collecting surfaces, inclined respect magnetic field. The method based on one-dimensional fluid model, which we use relate unperturbed velocity components (the quantities wish measure) density perturbations caused by probe. In this way are able establish link between electric saturation currents collected surfaces velocity. role of cross-field transport...
Long-distance toroidal correlations of potential and density fluctuations have been investigated at the TEXTOR tokamak [H. Soltwisch et al., Plasma Phys. Controlled Fusion 26, 23 (1984)] in edge electrode-biasing experiments. During biasing-induced H-mode, dc E×B shear flow triggers a zonal structure hence long-distance correlation fluctuations, whereas for there is nearly no correlation. These results indicate an intimate interaction between mean flows, significance long range...
The expansion of food production is getting more important due to a rising world population, which relying on security regional and local scale. Intensive systems create negative impact the ecosystem because agrochemical pollution nutrient rich water discharges into nearby rivers. Furthermore, these are highly depending resources causing scarcity soil erosion overexploitation natural in general. objective this article review usage two most intensive systems, agriculture aquaculture showing...
Abstract Efficient Electron Cyclotron Resonance Heating (ECRH) breakdown and pre-ionization can be achieved with fundamental X-mode, while higher harmonics introduce excessive stray radiation. Fundamental heating however is characterized by a low cut-off density, introducing additional power absorption mechanisms in the plasma. A good knowledge of these necessary to use X-mode as an efficient method. Numerous experiments were performed on TOroidally MAgnetized System (TOMAS) study deposition...
In this paper the 0D description of magnetized toroidal hydrogen–helium RF discharges is presented. The model has been developed to obtain insight into ICRF plasma parameters, particle fluxes walls and main collisional processes, which especially relevant for comprehension wall conditioning discharges. based on energy balance equations nine principal species: H, H+, H2, , He, He+, He2+ e−. It takes account (1) elementary atomic molecular collision such as excitation/radiation, ionization,...
Direct measurements of residual stress (force) have been executed at the edge TEXTOR tokamak using multitip Langmuir and Mach probes, together with counter-current NBI torque to balance existing toroidal rotation. Substantial force observed plasma boundary, confirming existence a finite as possible mechanisms drive intrinsic In low-density discharges, displays quasi-linear dependence on local pressure gradient, consistent theoretical predictions. At high-density shots are strongly...