A5089813675- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Plasma Diagnostics and Applications
- Solar and Space Plasma Dynamics
- Superconducting Materials and Applications
- Laser-Plasma Interactions and Diagnostics
- Geomagnetism and Paleomagnetism Studies
- Nuclear reactor physics and engineering
- Nuclear Physics and Applications
- Model Reduction and Neural Networks
- Laser-induced spectroscopy and plasma
- Music Technology and Sound Studies
- Solidification and crystal growth phenomena
- Advancements in Semiconductor Devices and Circuit Design
- Silicon Carbide Semiconductor Technologies
- Astro and Planetary Science
- Electrostatic Discharge in Electronics
- Oil and Gas Production Techniques
- Particle accelerators and beam dynamics
- Fusion materials and technologies
- Scientific Research and Discoveries
- Atomic and Subatomic Physics Research
- Non-Destructive Testing Techniques
- Plasma and Flow Control in Aerodynamics
- Geophysics and Gravity Measurements
American Institute of Aeronautics and Astronautics
2017-2022
University of Washington
2014-2022
CTFusion (United States)
2020
Swansea University
2002
University of Wales
2002
Building Research Establishment
1971
Public Works
1970
Plasmas are highly nonlinear and multiscale, motivating a hierarchy of models to understand describe their behavior. However, there is scarcity plasma lower fidelity than magnetohydrodynamics (MHD), although these reduced hold promise for understanding key physical mechanisms, efficient computation, real-time optimization control. Galerkin models, obtained by projection the MHD equations onto truncated modal basis, data-driven modern machine learning system identification, can furnish this...
We demonstrate the application of Dynamic Mode Decomposition (DMD) for diagnostic analysis nonlinear dynamics a magnetized plasma in resistive magnetohydrodynamics. The DMD method is an ideal spatio-temporal matrix decomposition that correlates spatial features computational or experimental data while simultaneously associating activity with periodic temporal behavior. can produce low-rank, reduced order surrogate models be used to reconstruct state system high fidelity. This allows...
Accurate and efficient circuit models are necessary to control the power electronic circuits found on plasma physics experiments. Tuning controlling behavior of these is inextricably linked performance. Linear greatly preferred for applications due their well-established performance guarantees, but they typically fail capture nonlinear dynamics changes in experimental parameters. Data-driven system identification can help mitigate shortcomings by learning interpretable accurate reduced-order...
The sheared-flow-stabilized Z pinch concept has been studied extensively and is able to produce fusion-relevant plasma parameters along with neutron production over several microseconds. We present here elevated electron temperature results spatially temporally coincident the source. An optical Thomson scattering apparatus designed for FuZE device measures temperatures in range of 1–3 keV on axis device, 20 cm downstream nose cone. 17-fiber system radial profiles temperature. Scanning laser...
Accurate and efficient plasma models are essential to understand control experimental devices. Existing magnetohydrodynamic or kinetic nonlinear, computationally intensive, can be difficult interpret, while often only approximating the true dynamics. In this work, data-driven techniques recently developed in field of fluid dynamics leveraged develop interpretable reduced-order plasmas that strike a balance between accuracy efficiency. particular, dynamic mode decomposition (DMD) is used...
Increasing the helicity injector drive frequency up to 68.5 kHz on Helicity Injected Torus-Steady Inductive (HIT-SI) experiment has produced spheromaks with current amplifications of 3.8, ideal n = 1 kink stability, improved toroidal symmetry and pressure confinement. Current centroid calculations from surface magnetic probes show an outward shift in field at frequencies above 50 kHz. Grad-Shafranov equilibria indicate confinement higher operating frequencies. The minimum characteristic...
In 1964 an electronic system (“assisted resonance”) to lengthen the reverberation time over a limited frequency range was installed experimentally in Royal Festival Hall, London. Following success of this experimental installation, covered extended (to 58–700 Hz) and installation made permanent. This paper describes operation permanent system, its objective subjective effects. Typically, empty auditorium has been increased 125-Hz octave band from 1.4 2.5 sec.
We present application of three scalar metrics derived from the Biorthogonal Decomposition (BD) technique to evaluate level agreement between macroscopic plasma dynamics in different data sets. BD decomposes large sets, as produced by distributed diagnostic arrays, into principal mode structures without assumptions on spatial or temporal structure. These have been applied validation Hall-MHD model using experimental Helicity Injected Torus with Steady Inductive helicity injection experiment....
The Helicity Injected Torus-Steady Inductive (HIT-SI) injectors have been operated experimentally and simulated with a 3D pressureless Hall magnetohydrodynamic (MHD) code (NIMROD) at frequencies of 14.5, 36.8, 53.5 68.5 kHz. Simulations are compared to experimental data using biorthogonal decomposition (BD) real synthetic surface magnetic probe signals. First, the time-averaged field squared (B2), measured by probes, is between experiment simulation. Next, spatial basis set from reference...
The HIT-SI3 experiment uses a set of inductively driven helicity injectors to apply non-axisymmetric current drive on the edge plasma, driving an axisymmetric spheromak equilibrium in central confinement volume. These perturbation that oscillates time, with relative temporal phasing modifying mode structure applied perturbation. A three experimental discharges different spectra are modelled using NIMROD extended magnetohydrodynamics code, and comparisons made both magnetic fluid...
A two-temperature magnetohydrodynamic (MHD) model, which evolves the electron and ion temperatures separately, is implemented in PSI-Tet code used to model plasma dynamics HIT-SI experiment. When compared with single-temperature Hall-MHD, Hall-MHD demonstrates improved qualitative agreement experimental measurements, including: far-infrared interferometry, Doppler spectroscopy, Thomson scattering, magnetic probe measurements. The utilized for simulations both NIMROD codes at a number of...
Two-photon laser-induced fluorescence measurements were performed on the helicity injected torus (HIT-SI3) device to determine density and temperature of background neutral deuterium population. Measurements taken in 2 ms long pulsed plasmas after inductive injectors turned off. Attempts measure neutrals during main phase plasma unsuccessful, likely due being below detection threshold diagnostic. An unexpectedly low atomic was measured afterglow; roughly 100 times lower than theoretical...
The conceptual design of an experiment for demonstrating and developing the efficient sustainment a spheromak with sufficient confinement is presented. “Sufficient” means that current drive power can heat plasma to its stability β limit. Previous transient experiments showing in kilo-electron-volt temperature range no external toroidal field coil, recent results on Helicity Injected Torus Steady Inductive (HIT-SI) confinement, potential imposed dynamo (IDCD) solving other fusion issues, very...
The helicity injected torus with steady inductive injection device is a simply-connected toroidal that forms and sustains axisymmetric spheromak equilibria through the use of injection, which inject magnetic drive non-axisymmetric currents on edge plasma. Simulations high-gain scenarios, using NIMROD code based models validated low gain experimental operations, indicate formation closed flux surfaces at current amplifications six. Despite scheme adding perturbations order , these are able to...
The helicity injected torus-steady inductive (HIT-SI) experiment uses steady injection to form a spheromak equilibrium and sustain the structure against resistive decay. Helicity is performed using two half-tori “injectors” connected main plasma volume, whose fields are oscillated in an AC manner. properties of sustained have been experimentally observed vary with frequency injector oscillation, producing higher current gains more-symmetric outwardly shifted centroids frequency. A...
A new, four-chord, CO2/He–Ne heterodyne interferometer has been designed and built for measuring line-averaged plasma density in the HIT-SI3 subsequent HIT-SIU sustained spheromak devices. The two-color system successfully eliminates vibration-induced errors caused by mirrors that are secured to vacuum chamber is able resolve electron densities ne full operating range of 1018–1020 m−3 both experiments with an integrated error 4.7 × 1017 m−2. Data presented from high toroidal current...
We report the plasma pressure reached inside central column of a sheared-flow-stabilized Z-pinch using Thomson scattering measurements. Building on previously reported experimental results and analysis methods established for high temperature moderate density plasmas generated FuZE device, we show evidence region with higher electron density, which is consistent pinch behavior. Elevated temperatures up to 2.25 ± 0.8 keV densities (4.9±0.2)×1017 cm−3 are observed temporally coincide fusion...