A5083619704- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Superconducting Materials and Applications
- Plasma Diagnostics and Applications
- Laser-Plasma Interactions and Diagnostics
- Dust and Plasma Wave Phenomena
- Particle accelerators and beam dynamics
- Nuclear physics research studies
- Geophysics and Gravity Measurements
- Non-Destructive Testing Techniques
- Electrostatic Discharge in Electronics
- Advanced Chemical Physics Studies
- Scientific Measurement and Uncertainty Evaluation
- Fusion materials and technologies
- Fluid Dynamics and Turbulent Flows
- Quantum, superfluid, helium dynamics
- Advanced NMR Techniques and Applications
- Inertial Sensor and Navigation
- Magnetic Field Sensors Techniques
- Plasma and Flow Control in Aerodynamics
- Particle Dynamics in Fluid Flows
- Railway Engineering and Dynamics
- Geotechnical Engineering and Soil Stabilization
- Traffic Prediction and Management Techniques
Oak Ridge National Laboratory
2021-2024
Ain Shams University
2015-2023
The University of Texas at Austin
2015-2023
Fusion (United States)
2020-2023
Fusion Academy
2020-2023
Princeton Plasma Physics Laboratory
2021-2022
Princeton University
2021-2022
General Atomics (United States)
2022
Columbia University
2022
University of Colorado Boulder
2021
This paper reports on the development of reduced models for electron temperature gradient (ETG) driven transport in pedestal. Model is enabled by a set 61 nonlinear gyrokinetic simulations with input parameters taken from pedestals broad range experimental scenarios. The simulation data has been consolidated new database data, Multiscale Gyrokinetic Database (MGKDB), facilitating analysis. modeling approach may be considered generalization standard quasilinear mixing length procedure....
Abstract Recent evidence points toward the microtearing mode (MTM) as an important fluctuation in H-mode pedestal for anomalous electron heat transport. A study of instabilities region carried out using gyrokinetic simulations to model ELMy DIII-D discharge (USN configuration, 1.4 MA plasma current, and 3 MW heating power) is presented. The produce MTMs, identified by predominantly electromagnetic flux, small particle a substantial degree tearing parity. magnetic spectrogram from Mirnov...
This article presents a global reduced model for slab-like microtearing modes (MTMs) in the H-mode pedestal, which reproduces distinctive features of experimentally observed magnetic fluctuations, such as chirping and discrete frequency bands at noncontiguous mode numbers. Our model, importantly, includes variation diamagnetic frequencies, is necessary to reproduce experimental observations. The key insight underlying this that MTM instability enabled by alignment rational surface with peak...
Abstract The spatial and spectral characteristics of the turbulent plasma density, electric fields, ion drift in ionospheric E region are studied using a new set nonlinear fluid equations. model combines both Farley‐Buneman (Type‐I) Gradient‐Drift (Type‐II) instabilities equatorial electrojet. In our unified instabilities, we include viscosity momentum equation electron inertia equation. These two terms play an important role stabilizing growing modes linear regime driving instability into...
In this study, gyrokinetic simulations are used to study pedestal fluctuations for DIII-D discharge 174082 using the GENE code. Nonlinear local indicate that electron heat flux has contributions from temperature gradient-driven transport but at levels insufficient satisfy power balance. We show microtearing modes (MTM) and neoclassical likely account remaining observed energy losses in ion channels, respectively. The MTM instabilities found consistent with high-frequency identified magnetic...
Transport from turbulence driven by the electron temperature-gradient (ETG) instability is likely a major source of heat losses through pedestal. Due to extreme gradients and strong shaping, ETG instabilities in pedestal are distinct those core, having, for example, multiple branches (toroidal slab) different wavenumber ranges. its importance transport, rather exotic character, rigorous multi-code benchmarking exercise imperative. Here, we describe such an exercise, wherein have carried out...
Abstract A long standing shortfall in the predicted L-mode edge energy transport by reduced quasi-linear models of gyrokinetic turbulent has been resolved. The improved model TGLF-SAT2 higher fidelity to simulations electron-scale contribution electron and ion-scale flux surface shape dependence transport. success predicting Ohmic profiles is critical whole pulse simulation opens door prediction H-mode power threshold.
Experimental data on electromagnetic fluctuations in DIII-D, made available by the Faraday-effect Radial Interferometer-Polarimeter (RIP) diagnostic, is examined comparison with detailed gyrokinetic simulations using Gyrokinetic Electromagnetic Numerical Experiment (GENE). The diagnostic has unique capability of making internal measurements fluctuating magnetic fields $\frac{\int n_e \delta B_r dR}{\int dR}$. Local linear identify microtearing modes (MTMs) over a substantial range toroidal...
We report on a detailed study of magnetic fluctuations in the JET pedestal, employing basic theoretical considerations, gyrokinetic simulations, and experimental fluctuation data, to establish physical basis for their origin, role, distinctive characteristics. demonstrate quantitative agreement between simulations microtearing modes (MTMs) two frequency bands with corresponding toroidal mode numbers n=4 8. Such disparate scales, substantial gaps numbers, are commonly observed pedestal...
Farley-Buneman modes are an example of the collisional instability, which is thought to be dominant mechanism for irregularities in low ionosphere region. Despite high collisionality due electron-neutral and ion-neutral collisions, kinetic effects associated with finite temperature important determination mode frequencies growth rate. This especially ion component that largely unmagnetized cyclotron frequency. The thermal strongly pronounced shorter wavelengths crucial rate cut-off at...
Abstract Progress in understanding the coupling between plasma instabilities equatorial electrojet based on a unified fluid model is reported. Simulations with parameters set to various ionospheric background conditions revealed properties of gradient‐drift and Farley‐Buneman instabilities. Notably, sharper density gradients increase linear growth rates at all scales, whereas variations cross‐field E × B drift velocity only affect small‐scale A formalism defining turbulent fluctuation energy...
This article presents a survey of NSTX cases to study the microtearing mode (MTM) stabilities using newly developed global reduced model for Slab-Like Microtearing modes (SLiM). A trained neutral network version SLiM enables rapid assessment (0.05s/mode) MTM with $98\%$ accuracy providing an opportunity systemic equilibrium reconstructions based on matching experimentally observed frequency bands and prediction across wide range parameters. Such method finds some success in discharges,...
Several configurations for the core and pedestal plasma are examined a predefined tokamak design by implementing multiple heating/current drive (H/CD) sources to achieve an optimum configuration of high fusion power in noninductive operation while maintaining ideally magnetohydrodynamic (MHD) stable using IPS-FASTRAN framework. is component-based lightweight coupled simulation framework that used simulate magnetically confined integrating set high-fidelity codes construct equilibrium (EFIT,...