Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 29 for “"plasma turbulence"”.
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Studies of aspect angle dependence of plasma turbulence at HAARP
… to generate and study strong Langmuir turbulence (SLT) in the interaction region of overdense ionospheric plasma. Diagnostics included the Modular UHF Ionospheric Radar (MUIR) sited at HAARP, the Super DARN-Kodiak HF radar, and HF receivers to record stimulated electromagnetic emissions …
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Discontinuous Galerkin modeling of plasma turbulence in a simple magnetized torus
Plasma turbulence in the Texas Helimak, a simple magnetized torus (SMT) experiment, has been simulated with fluid and gyrokinetic continuum models that employ the discontinuous Galerkin (DG) computational method. SMTs are physical approximations of a sheared cylinder and, with simple magnetic …
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Plasma turbulence in the equatorial electrojet observations, theories, models, and simulations
The plasma turbulence in the equatorial electrojet due to the presence of two different plasma instability mechanisms has been observed and studied for more than seven decades. The sharp density-gradient and large conductivity give rise to gradient-drift and Farley-Buneman instabilities, …
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440 MHz radar observations of plasma turbulence in the auroral lower ionosphere
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1989.
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Physics-informed machine learning techniques for edge plasma turbulence modelling in computational theory and experiment
Edge plasma turbulence is critical to the performance and operation of magnetic confinement fusion devices. Drift-reduced Braginskii two-fluid theory has for decades been widely applied to model boundary plasmas with varying success. Towards better understanding edge turbulence in both theory and …
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Could global warming affect space weather? : case studies of intense ionospheric plasma turbulence associated with natural heat sources
… of a series of highly-structured ionospheric plasma turbulence over Arecibo on the nights of 22/23 and 23/24 July, 2006. Incoherent scatter measurements by Arecibo radar, airglow measurements using MIT PSFC's all-sky imaging system (ASIS), together with TEC measurements from GPS satellite …
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Generation of acoustic-gravity waves in ionospheric HF heating experiments : simulating large-scale natural heat sources
… waves (AGWs) that might trigger widespread plasma turbulence in the ionospheric layer. The main hypothesis is that, the thermal gradients associated with the heat wave fronts could act as a source of powerful AGW capable of triggering ionospheric plasma turbulence over extensive areas. In …
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The interaction of shock waves and dispersive waves
… system mimics the Zakharov equations from weak plasma turbulence theory but replaces the linear wave equation in that system by a nonlinear equation allowing shock formation. This nonlinear equation is a hyperbolic conservation law forced by the dispersive wave.
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Simultaneous multi-angle measurements of plasma turblence at HAARP
… to generate and study strong Langmuir turbulence (SLT) in the interaction region of overdense ionospheric plasma. Diagnostics included the Modular UHF Ionospheric Radar (MUIR) sited at HAARP, the Super DARN-Kodiak HF radar, and HF receivers to record stimulated electromagnetic emissions …
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Neoclassical polarization
… to be the predominant saturation mechanism of plasma turbulence. Rosenbluth and Hinton(R-H) have shown that the zonal flow level is inversely proportional to the plasma radial polarizability due to magnetic drift departure from a flux surface. In another calculation, Hinton and Rosenbluth (H-R) …
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Studies of Edge Fluctuations of Negative Triangularity Plasma on TCV using a New Gas-Puff Imaging Diagnostic
… devices requires thorough analysis of edge plasma turbulence, which plays a key role in dealing with the exhaust heat and particle loads on the wall materials. Edge plasma turbulence differs depending on various plasma conditions including plasma shape, e.g., the triangularity (δ). Negative …
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Investigation of thermal filamentation instability over Gakona, Alaska
… plate waveguides in mid-latitude ionospheric plasmas during Arecibo, Puerto Rico heating experiments in 1997. The geometry of the kilometer-scale parallel plates predicted by thermal filamentation depends on the mode of the transmitted heater wave, as does the threshold to excite this …
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Modeling of Plasma Irregularities Associated with Artificially Created Dusty Plasmas in the Near-Earth Space Environment
Plasma turbulence associated with the creation of an artificial dust layer in the earth's ionosphere is investigated. The Charged Aerosol Release Experiment (CARE) aims to understand the mechanisms for enhanced radar scatter from plasma irregularities embedded in dusty plasmas in space. Plasma …
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Excitation of forced ion acoustic waves, large plasma sheets, and magnetic field fluctuations over Gakona, Alaska
… waves", and (2) "simultaneous excitation of plasma density fluctuations and geomagnetic field fluctuations" are reported in my M.S. thesis. The data was acquired in our experiments conducted at Gakona, Alaska from summer 2007 to winter 2008, using DoD/NSF-funded HAARP facilities and our own …
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Exploiting pulsar timing at low radio frequencies: applications to Pulsar Timing Arrays, Interstellar medium and HII regions
… observational data, I investigated the role of plasma turbulence along the lines of sight of LOFAR pulsars. Particular attention is given to discrete ionised regions, such as HII regions, whose presence can shape both the amplitude and the spectral behaviour of DM fluctuations. This approach …
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Construction and operation of a Mirror Langmuir Probe diagnostic for the Alcator C-Mod tokamak
… systems can not resolve the rapid changes in plasma electron temperature, floating potential and ion saturation current that are associated with plasma turbulence. Moreover, no existing system can provide real-time output of these three parameters using a single electrode. To remedy this …
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Numerical Simulation of Ion-Cyclotron Turbulence Generated by Artificial Plasma Cloud Release
Possibilities of generating plasma turbulence to provide control of space weather processes have been of particular interest in recent years. Such turbulence can be created by chemical released into a magnetized background plasma. The released plasma clouds are heavy ions which have ring velocity …
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Genesis, dynamics, and dissipation of turbulent magnetic fields
… fields are amplified and sustained by turbulent plasma motions--are well understood. In addition, the role played by these fields in determining the material and thermodynamic properties of cosmic plasmas, which strongly impact various astrophysical phenomena, is still unknown. This thesis …
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Lithium pellet injection into high pressure magnetically confined plasmas
… into high temperature magnetically confined plasmas is characterized by rapid oscillations in the ablation rate, and the formation of field aligned filaments in the ablatant. High speed imaging of the ablation (> 250, 000 frames/second) during the 2003-2004 campaign revealed that these …
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Linear and nonlinear stochastic differential equations with applications
… random problems: model hydrodynamic and Vlasov-plasma turbulence. The equations for the phenomenon of hydrodynamic turbulence are examined in more detail at the level of the quasi-linear approximation, which is valid for small turbulence Reynolds numbers. Closed form solutions are found for the …
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