Browsing Auburn Theses and Dissertations by Department "Physics"
Now showing items 41-60 of 101
Gyrokinetic Electron and Fully Kinetic Ion Particle Simulation on Current Sheet Instabilities
(2016-07-20)
Linear eigenmode stability properties of three-dimensional instabilities in a Harris current sheet with a finite guide magnetic field are systematically studied employing the gyrokinetic electron and fully kinetic ion ...
Imaging Electron-Driven Dynamics in Dissociative Electron Attachment to Gas Molecules
(2013-07-19)
The design and construction of a new ion-momentum spectrometer for the study of
electron-molecule interactions at Auburn University (AU) is detailed with emphasis on the
phenomenon of dissociative electron attachment ...
Imaging Multi-Particle Atomic and Molecular Dynamics in Dissociative Electron Attachment to CF4 and Double Photoionization of NH3 Molecules
(2021-05-18)
The experimental process and scientific study of two molecular interactions is presented. The first experiment consist of the phenomenon of dissociative electron attachment, (DEA), to Carbon Tetrafluoride, CF4, with the ...
Imaging Polyatomic Molecules in Three Dimensions Using Molecular Frame Photoelectron Angular Distributions
(2012-05-10)
We demonstrate a method for determining the full three-dimensional molecular frame photoelectron angular distribution in polyatomic molecules using methane as a prototype. Simultaneous double Auger decay and subsequent ...
Interactions between Electromagnetic Ion Cyclotron Waves and Protons in the Magnetosphere: SCATHA Results
(2007-05-15)
Electromagnetic ion cyclotron (EMIC) waves and their role in governing proton populations in the ring current and radiation belt regions are of importance in understanding the dynamics of the Earth’s magnetosphere. The ...
Investigating Faculty Perspectives on Written Qualifying Exams in Physics
(2024-03-12)
Doctoral qualifying exams are considered essential in assessing a student's readiness for research and advanced studies. Despite their significant role in many physics’ programs, questions have been raised about their ...
An investigation into the role of metastable states on excited populations of weakly ionized argon plasmas, with applications for optical diagnostics.
(2017-07-21)
Performing spectroscopic measurements of emission lines in relatively cold laboratory plasmas is challenging because the plasma is often neutral-dominated and is not in thermal equilibrium. However, these types of plasma ...
Investigation of Kinetic Physics of Magnetic Reconnection under a Finite Guide Field
(2011-08-08)
Magnetic reconnection, the process by which the magnetic energy is converted into heat and flow energy, is believed to
be a very important process in space and laboratory plasmas. Among various reconnection models, the ...
Investigation of Point Defects in AlGaN/GaN High Electron Mobility Transistor Heterostructures Grown on Si Wafers
(2016-05-18)
This PhD dissertation focuses on the investigation of surface/interface defects in AlGaN/GaN high
electron mobility transistors (HEMTs) on Si wafers for power electronic applications. Recently, significant
attention has ...
Investigation of Probe-Induced Dust Voids in a Weakly Magnetized Dusty Plasma
(2019-12-06)
Dust voids, or regions free of dust grains surrounded by dusty plasmas, have been observed in
a wide array of experimental configurations, from microgravity systems, to 3-dimensional dust
clouds, to 2-dimensional monolayers. ...
Investigation of the Redistribution of Kinetic Energy in a Microgravity Complex (Dusty) Plasma
(2022-07-28)
In the presence of gravity, the micron-sized charged dust particles in a complex plasma are compressed to thin layers, but under the microgravity conditions of the Plasma Kristall-4 (PK-4) experiment on the International ...
Laboratory Investigation of the Dynamics of Shear Flows in a Plasma Boundary Layer
(2013-10-28)
The laboratory experiments presented in this dissertation investigate a regime of instabilities that occur when a highly localized, radial electric field oriented perpendicular to a uniform background magnetic field gives ...
Laser Field Interactions with Atoms and Molecules
(2016-12-09)
This dissertation explores multiple areas of laser matter interactions.
It studies four main topics: multi-photon (few photon) double ionization of He, double photoionization of He-like systems
from level resolved ...
Low edge safety factor disruptions in the Compact Toroidal Hybrid: Operation in the low-q regime, passive disruption avoidance and the nature of MHD precursors
(2016-08-02)
The nominally axisymmetric (2-D) magnetic configuration in the form of a tokamak has proven to be the best candidate for a future reactor, and yet it is susceptible to instabilities which lead to a complete loss of the ...
Magnetohydrodynamic equilibrium and stability in rotating tokamak plasmas
(2019-04-29)
Tokamak plasmas display finite macroscopic rotation in standard machine operation. Yet, the theoretical understanding of stationary states is lacking as compared to static configurations. In this work, we investigate the ...
Many-Body Dipole Interactions
(2008-08-15)
This dissertation presents the study of controllable but strong long-range interaction between dipoles. In particular, we investigate the excitation and interaction between atoms in a cold gas where the collisional time ...
Measurement of the phase space distribution in a complex plasma
(2012-04-18)
The development of a diagnostic technique that allows measurement of the six dimensional phase space distribution for the dust component of a plasma system is presented. In the course of the measurement and analysis ...
Measurement of the thermal properties of a weakly-coupled complex (dusty) plasma
(2006-12-15)
Knowledge of the velocity space distribution function facilitates the characterization of the thermal and dynamical properties of a system. In this work, a comprehensive series of experiments and numerical simulations are ...
Measurements and Modification of Sheared Flows and Stability on the Compact Toroidal Hybrid Stellarator
(2012-04-25)
Sheared flows arising from spatially inhomogeneous, transverse electric fields are common phenomena found in space, laboratory, and fusion plasmas. These flows are a source of free energy that can drive or suppress ...
Microparticle Dynamics in Strongly Magnetized Low Temperature Plasmas
(2017-07-25)
Dusty plasma systems consist of charged microparticles (usually called dust grains) embedded in a background plasma. The dust component can significantly modify the background plasma by collecting electrons and ions, thus ...