Matching Items (2)
Description
Orbiting space debris is an active issue that affects the capability of space launch for future satellites, probes, and space shuttles, and it will become a nearly insurmountable problem without action. Debris of varying sizes and speeds orbit the Earth at a range of heights above the atmosphere and need to be removed to avoid damage to crucial equipment of active orbiting satellites including the International Space Station. Finding a feasible solution to space debris removal requires that several facets be covered to become a reality; these include being aware of the problem in magnitude and source. This literature assessment covers the magnitude of space debris in low-earth and geosynchronous orbit as well as collision events which have increased the amount of space debris. There have been efforts made by several space agencies to control the amount of space debris added to orbit by current and future launches over the last decade \u2014 serving as a temporary fix before removal can be executed. This paper explores known removal efforts through mitigation, projects conceived and tested by DARPA, related space policies and laws, CubeSat technology, and the cataloguing of known space debris. To make space debris removal a reality, roadblocks need to be removed to acquire permission from states or countries for space missions. For example, these restrictions are in place to protect the assets of several countries and organizations. Guidelines set to curb the growth of space debris fail to prevent the growth due to the restrictions for ownership rights making them not as effective. This paper covers space policy and laws, the economy, satellite ownership, international conflict, status of space debris, and the overall feasibility of space debris removal. It will then discuss currently proposed solutions for the removal of space debris. Finally, this paper attempts to weight the advantages and disadvantages of the idea that space debris removal should include the opportunity to recycle materials. For example, defunct satellites and other discarded space crafts could be used for future launches. It will conclude with a personal exploration of what materials can be recycled, what chemical processes can be used to break down materials, and how to combine recycling and chemical processes for space-based recycling stations between Earth and the moon. The overall question that drives the search for making space debris removal a reality is whether it is feasible in multiple areas including technologically, legally, monetarily, and physically.
ContributorsBreden, Elizabeth Catherine (Author) / Foy, Joseph (Thesis director) / Thoesen, Andrew (Committee member) / Maximon, Leonard (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
Because of its massive nature and simple two-body structure, the heavy meson bottomonium (the flavorless bound state of the bottom quark and anti-quark) is among the simplest systems available for the study of the strong force and quantum chromodynamics (QCD)—a feature which has made it of special interest to particle physicists.
Despite being bound by the strong force, bottomonium exhibits a rich spectrum of resonances corresponding to excited states extremely analogous to that of positronium or even familiar atomic systems. Transitions between these levels are possible via the absorption or emission of either a photon, gluon, or gluons manifesting as light hadrons. The goal of this thesis was to establish a theoretical value for the currently unmeasured partial decay width for one such transition—the electromagnetic decay channel hb -> etab gamma. To this end, two methods were utilized.
The first approach relied on the presumption of a nonrelativistic constituent quark model interacting via a simple static potential, allowing for radial wave functions and energy eigenvalues to be obtained for the states of interest via the Schrödinger equation. Upon an application of the standard electromagnetic multipole expansion followed by a utilization of the electric dipole E1 decay width formula, a value of 57.7 ± 0.4 keV was obtained.
The second approach stemmed from the effective Lagrangian describing the bottomonium P to S electromagnetic transitions and relied on the presumption that a single coupling constant could be approximated as describing all nP to mS transitions regardless of spin. A value for this coupling constant could then be extracted from the 1P to 1S spin triplet data and used to predict the width for the singlet 1P to 1S transition. The partial decay width value found in this manner was 47.8 ± 2.0 keV.
Various other methods and models have established a predicted range of 35 to 60 keV for this partial decay width. As the values determined in this thesis fall within the expected range, they agree well with our current understanding of this electromagnetic transition and place further confidence on the expected range.
Despite being bound by the strong force, bottomonium exhibits a rich spectrum of resonances corresponding to excited states extremely analogous to that of positronium or even familiar atomic systems. Transitions between these levels are possible via the absorption or emission of either a photon, gluon, or gluons manifesting as light hadrons. The goal of this thesis was to establish a theoretical value for the currently unmeasured partial decay width for one such transition—the electromagnetic decay channel hb -> etab gamma. To this end, two methods were utilized.
The first approach relied on the presumption of a nonrelativistic constituent quark model interacting via a simple static potential, allowing for radial wave functions and energy eigenvalues to be obtained for the states of interest via the Schrödinger equation. Upon an application of the standard electromagnetic multipole expansion followed by a utilization of the electric dipole E1 decay width formula, a value of 57.7 ± 0.4 keV was obtained.
The second approach stemmed from the effective Lagrangian describing the bottomonium P to S electromagnetic transitions and relied on the presumption that a single coupling constant could be approximated as describing all nP to mS transitions regardless of spin. A value for this coupling constant could then be extracted from the 1P to 1S spin triplet data and used to predict the width for the singlet 1P to 1S transition. The partial decay width value found in this manner was 47.8 ± 2.0 keV.
Various other methods and models have established a predicted range of 35 to 60 keV for this partial decay width. As the values determined in this thesis fall within the expected range, they agree well with our current understanding of this electromagnetic transition and place further confidence on the expected range.
ContributorsIreland, Aurora Nicole (Author) / McCartney, Martha (Thesis director) / Foy, Joseph (Committee member) / Maximon, Leonard (Committee member) / Department of Physics (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12