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Full-Text Articles in Physics
Electron Yield Decay Curves For Analysis Of Sample Charging And Neutralization, Matthew Robertson
Electron Yield Decay Curves For Analysis Of Sample Charging And Neutralization, Matthew Robertson
Utah Space Grant Consortium
Excess charge on a material will affect the electron yield of the material. Electron yield is an attribute of materials which describe how the material behaves when irradiated with electrons. It is the ratio of the number of electrons going into the material over the number of electrons leaving the material. Understanding how a sample charges is important in both how it affects the electron yield and how it can be neutralized.
Comparing P-11b To D-3he Fusion For Direct Drive Fusion Rockets, Christopher Hooper
Comparing P-11b To D-3he Fusion For Direct Drive Fusion Rockets, Christopher Hooper
Utah Space Grant Consortium
Direct Fusion Drive (DFD) is a theoretical configuration that uses a magnetically confined fusing plasma to provide thrust for a rocket. In the words of the original authors, Princeton Satellite Systems (PSS) and Razinet al., it is “...a compact, anuetronic fusion engine [which] will enable more challenging exploration missions in the solar system.” DFD is proposed as a theoretical alternative to chemical and ion propulsion rockets – as seen in Table 1, it has clear advantages over both in exhaust velocity (specific impulse) and mass ratio, and a large advantage over ion propulsion in thrust and thrust-to-weight ratio. Despite being …
A Study Of Oxidation In Thin-Film Uranium-Niobium Alloys, Logan C. Page
A Study Of Oxidation In Thin-Film Uranium-Niobium Alloys, Logan C. Page
Utah Space Grant Consortium
Uranium, a nuclear fuel material, can oxidize and degrade in reactor conditions. Previous studies have shown oxidation resistance in a uranium-niobium alloy, U-6Nb (six weight percent niobium in uranium). The nature of the oxides that form on sputtered U-6Nb thin films after long exposure to air was previously explored using neutron diffraction at Los Alamos National Laboratory. In the present work, we deposited thin films of uranium-niobium alloys for oxidation studies. We used ellipsometry to quantify the oxide growth over time as a function of niobium content. We found that the oxide thickness increases linearly with the logarithmic of time. …
Comparison Of Rayleigh-Scatter Lidar Temperature Climatologies In The Mesosphere And Lower Thermosphere Between The Traditional Reduction Method And The New Optimal Estimation Method, Jonathan Price
Utah Space Grant Consortium
An optimal estimation method (OEM) was used to obtain all-night temperature profiles from Rayleigh-scatter lidar (RSL) observations obtained by the original and updated lidar systems at Utah State University (USU). These data were used to produce annual climatologies of temperatures above USU. The climatology of temperatures from the original lidar, which operated from late 1993 through 2004, was compared with the climatology produced using the widely used Hauchecorne-Chanin method (HC). This comparison highlights the similarities at lower altitudes and differences, which start between 70 km and 80 km and extend to the top altitudes with the OEM temperatures warmer on …
Seeking The Origin Of Electromagnetic Signatures Of Black Holes, Alexandra B. Chanson
Seeking The Origin Of Electromagnetic Signatures Of Black Holes, Alexandra B. Chanson
Utah Space Grant Consortium
Relativistic-jet formation in astrophysical black holes lacks a rigorously understood mechanism of energy extraction in the high-energy regime although, in recent years, progress has been made in extending the non-linear equations of Force-Free Electrodynamics (FFE) into the high-spin regime. In particular, M. J. Rodriguez and A. Strominger were able to show, using the Near Horizon Extremal Kerr spacetime, that the near horizon FFE solutions have an additional scaling symmetry which allows the construction of a pseudo-analytical infinite tower of solutions. These families of solutions stand in stark contrast to the relatively few full Kerr solutions found analytically: this tension can …