A5042258423- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Particle accelerators and beam dynamics
- Plasma Diagnostics and Applications
- Laser-Plasma Interactions and Diagnostics
- Solar and Space Plasma Dynamics
- Dust and Plasma Wave Phenomena
- Fusion materials and technologies
- Superconducting Materials and Applications
- Fluid Dynamics and Turbulent Flows
- GNSS positioning and interference
- Nuclear reactor physics and engineering
- Atomic and Subatomic Physics Research
- Electromagnetic Launch and Propulsion Technology
- Gas Dynamics and Kinetic Theory
- Computer Graphics and Visualization Techniques
- Electrostatic Discharge in Electronics
- Metaheuristic Optimization Algorithms Research
- Geomagnetism and Paleomagnetism Studies
- Particle Dynamics in Fluid Flows
- Tropical and Extratropical Cyclones Research
- Power System Optimization and Stability
- Metallurgical and Alloy Processes
- Solidification and crystal growth phenomena
- Optical Coatings and Gratings
Tokamak Energy (United Kingdom)
2023-2025
Los Alamos National Laboratory
2024-2025
The University of Texas at Austin
2017-2021
Princeton Plasma Physics Laboratory
2015-2021
Max Planck Institute for Plasma Physics
2021
Oak Ridge National Laboratory
2021
University of New Hampshire
2021
University of Colorado Boulder
2021
Rutgers, The State University of New Jersey
2021
University of Saskatchewan
2017-2020
Diagnostic tools for understanding the edge plasma behavior in fusion devices are essential. The main focus of present work is to infra-red (IR) diagnostics installed on Tokamak Energy’s spherical tokamak (ST40) and IR thermographic inversion tool, Functional Analysis Heat Flux (FAHF). FAHF designed multi-2D inversions within divertor tiles using finite difference method an explicit time stepping scheme. ST40’s re-entrant endoscope allows acquisition data with highest available effective...
The Electron Cyclotron Drift Instability (ECDI) driven by the electron $E\times B$ drift in partially magnetized plasmas is investigated with highly resolved particle-in-cell simulations. emphasis on two-dimensional effects involving parallel dynamics along magnetic field a finite length plasma dielectric walls. It found that instability develops as sequence of growing cyclotron harmonics demonstrating wave breaking and complex nonlinear interactions, being particularly pronounced ion...
Nonlinear dynamics of the electron-cyclotron instability driven by electron E×B current in a crossed electric and magnetic field is studied. In nonlinear regime, proceeds developing large amplitude coherent wave energy input from fundamental cyclotron resonance. Further evolution shows formation long wavelength envelope akin to modulational instability. Simultaneously, ion density development high-k content responsible for focusing sharp peaks on periodic cnoidal structure. It shown that...
Abstract ST40 is a compact, high-field ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>B</mml:mi> <mml:mi mathvariant="normal">T</mml:mi> <mml:mn>0</mml:mn> </mml:mrow> </mml:msub> <mml:mtext>⩽</mml:mtext> <mml:mn>2.1</mml:mn> <mml:mstyle scriptlevel="0"/> <mml:mtext>T</mml:mtext> </mml:math> ) spherical tokamak (ST) with mission to expand the physics and technology basis for ST route commercial fusion. The research programme covers...
A cross-comparison and verification of state-of-the-art European codes describing gradient-driven plasma turbulence in the core edge regions tokamaks, carried out within EFDA Task Force on Integrated Tokamak Modelling, is presented. In case ion temperature gradient (ITG) driven with adiabatic electrons (neglecting trapped particles), good/reasonable agreement found between various gyrokinetic/gyrofluid codes. The main physical reasons for some deviations observed nonlocal simulations are...
Direct measurements of micro-, meso-, and macroscale transport phenomena in the FT-2 tokamak are shown to be quantitatively reproduced by global full $f$ nonlinear gyrokinetic simulation predictions. A detailed agreement with mean equilibrium $E\ifmmode\times\else\texttimes\fi{}B$ flows, oscillating fine-scale zonal turbulence spectra observed a set sophisticated microwave backscattering techniques as well good fit thermal diffusivity data demonstrated. clear influence impurity ions on...
Local gyrokinetic simulations with the GENE code are used to investigate turbulent transport for different levels of neutral beam injection heating power in Tokamak à Configuration Variable (TCV) plasmas both positive and negative edge triangularity. The sensitivity heat fluxes respect main plasma parameters, including background gradients, impurity content, electron temperature, is systematically studied. experimentally measured recovered variations profiles compatible experimental error...
Abstract In a recent experiment in the FT-2 tokamak, intermittencies GAM and turbulence intensities throughout 13 ms were observed while changes density temperature profiles are insignificant. The intensity of fluctuations measured by two reflectometers recorded 21% suppression during period radial region r/a = 0.4 to 0.8. this paper, several linear simulations one global non-linear simulation using gyrokinetic code GENE covering ρ tor from 0.17 0.83 carried out. Linear out find dominant...
A technique, volumetric power optimization, is presented for enhancing the output of magnetic confinement fusion devices. Applied to a tokamak, this approach involves shifting burning plasma region larger volume while introducing minimal perturbations boundary shape. This edge perturbation—squareness—is analogous pinching and stretching boundary. Stability calculations confirm that alteration compatible with maintaining stability. optimization method optimizing could improve performance...
A two-dimensional particle-in-cell code for the simulation of low-frequency electromagnetic processes in laboratory plasmas has been developed. The uses Darwin method omitting wave propagation. separates electric field into solenoidal and irrotational parts. is calculated with a new algorithm based on equation vorticity. system linear equations readily solved using standard iterative method. electrostatic direct implicit algorithm. verified by reproducing two-stream instability, electron...
Quantitative reproduction of selected micro-, meso- and macro-scale transport phenomena as measured in the FT-2 tokamak is reached by Elmfire global full-f nonlinear gyrokinetic particle-in-cell simulation predictions. A detailed agreement with mean equilibrium flows, oscillating fine-scale zonal flows turbulence radial correlation length observed a set sophisticated microwave backscattering techniques, well good fit thermal diffusivity data central gradient region discharge are...
Covering the core and edge region of a tokamak, respectively, two gyrokinetic turbulence codes Gyrokinetic Electromagnetic Numerical Experiment (GENE) X-point Code (XGC) have been successfully coupled by exchanging three-dimensional charge density data needed to solve Poisson equation over entire spatial domain. Certain challenges for coupling procedure arise from fact that employ completely different numerical methods. This includes, in particular, necessity introduce mapping procedures...
A full f nonlinear 5D gyrokinetic electrostatic particle-in-cell code ELMFIRE using an implicit direct solution method for ion polarization drift and electron parallel velocity response to electric field its validation are described. The developed is applied transport analysis in a tokamak plasma at steep pressure gradient. role of turbulence neoclassical equilibrium determining the flux surface averaged radial component investigated, as well latter affecting saturation level turbulence. (©...
Abstract Turbulence spectra of density fluctuations measured with Doppler Reflectometry at the FT‐2 tokamak are com‐pared to full f nonlinear gyrokinetic simulations by means a synthetic reflectometry diagnostic. The experimental and power spectrum reflectometer show good agreements in both shift as well width spectrum, indicating comparable rotation spreading turbulence. averaged radial electric field is shown closely folllow neoclasical Hazeltine Hinton value Geodesic Acoustic mode clearly...
A full f gyrokinetic particle-in-cell simulation including Coulomb collisions is shown to reproduce the results from analytic estimates for parallel plasma conductivity in collisional parameter regime, with reasonably good agreement, when varying temperature and impurity content of plasma. Differences between models are discussed.
The gyrokinetic full f simulation code ELMFIRE has been used to perform the first global self-consistent computational study of dynamics radial electric field in presence turbulence an experimental toroidal configuration. Parameters have taken from FT-2 tokamak. Appreciable differences found comparison with neo-classical analytic estimate field, specially outer region higher level turbulence. Similar previously observed experiments. analysis included this work does not support hypothesis...
A direct implicit ion polarization gyrokinetic full f particle-in-cell approach is implemented with kinetic electrons in global tokamak transport simulations. The method applicable for calculations of rapid transients and steep gradients the plasma, which made feasible by recording charge density change drift together particle advancing. code has been successfully validated against linear nonlinear predictions unstable mode growth rates frequencies their turbulent saturation level. first...