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Full-Text Articles in Physical Sciences and Mathematics
Sensitivity Analysis Of Empirical Parameters In The Ionosphere-Plasmasphere Model, Janelle V. Jenniges
Sensitivity Analysis Of Empirical Parameters In The Ionosphere-Plasmasphere Model, Janelle V. Jenniges
Theses and Dissertations
A sensitivity analysis of empirical parameters used in physics-based models was completed in this study to determine their effect on electron densities and total electron content (TEC) in the ionosphere. The model used was the Ionosphere-Plasmasphere Model (IPM) developed by Utah State University. The empirical parameters studied include the O+/O collision frequency, zonal wind, secondary electron production, nighttime ExB drifts, and tidal structure. The sensitivity analysis was completed by comparing a default run of the IPM to a run with the parameter adjusted for three geophysical cases. Many of the comparisons resulted in nonlinear changes to the model …
Electron Multipactor: Theory Review, Comparison And Modeling Of Mitigation Techniques In Icepic, Neil G. Rogers
Electron Multipactor: Theory Review, Comparison And Modeling Of Mitigation Techniques In Icepic, Neil G. Rogers
Theses and Dissertations
Mitigation approaches for single surface multipactor at dielectric windows are investigated using Particle-In-Cell (PIC) simulations. Initially baseline susceptibility diagrams are constructed analytically and compared with self-consistent, dynamic system trajectories. The power deposited on the surface of a dielectric window in an HPM system is considered using three different methods and the results of PIC simulations. Geometric mitigation is then considered by varying the window orientation with respect to the HPM electric held. Small angular deviations, less than 20 degrees, from the nominal case of normal incidence show dramatic changes in the susceptibility diagram. A materials approach to mitigation is then …
Shockwave Interactions With Argon Glow Discharges, Nicholas S. Siefert
Shockwave Interactions With Argon Glow Discharges, Nicholas S. Siefert
Theses and Dissertations
The purpose of this research was study shock wave interactions with argon glow discharges. Specifically, this thesis sought to answer whether it is possible to compress nonequilibrium electrons at the shock wave. The results in the thesis found that both equilibrium and nonequilibrium electrons could be compressed at the shock front. The double layer at the shock front, normalized by electron temperature, matched the calculated values for the double layer within a factor or two in all cases. The results also demonstrate that excited metastable states can be compressed at the shock front, as well. The culmination of this effort …
Attenuation And Refraction Of An Electromagnetic Wave In An Electron Beam Generated Plasma, Nathaniel P. Lockwood
Attenuation And Refraction Of An Electromagnetic Wave In An Electron Beam Generated Plasma, Nathaniel P. Lockwood
Theses and Dissertations
Artificially generated plasmas may be employed to alter the propagation characteristics of electromagnetic waves. The purpose of this report is to study the propagation of electromagnetic waves in an electron beam generated plasma. To understand the physics related to this concept requires the development of computational tools dealing with a plasma created by an electron beam, an assessment of the temporal and spatial evolution of the plasma, and a characterization of the refraction and attenuation of electromagnetic (EM) waves in a collisional plasma. Three computer programs were developed to characterize the effectiveness of an electron beam generated plasma in refracting …