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UNDERSTANDING UNCERTAINTIES IN RESOLVED PHOTON STRUCTURE
Title
UNDERSTANDING UNCERTAINTIES IN RESOLVED PHOTON STRUCTURE
Creator
Zhan, Hengrui
Date
2017, 2017-07
Description
The construction of a photon collider has been urged, in order to study the properties of the Higgs boson and electroweak symmetry breaking....
Show moreThe construction of a photon collider has been urged, in order to study the properties of the Higgs boson and electroweak symmetry breaking. It would also provide unique possibilities for measurement of fusion to probe the hadronic structure of the photon. One scheme of design for the photon collider is a linear collider. A study shows that resolved photons contribute about 15% of the cross section to Higgs production with a mass of 120 GeV, but estimates of the resolved photon structure have so far varied greatly. Therefore, resolved photon structure is important to measure. This thesis focuses on the determination of the uncertainties of the cross section of bb production for better understanding of resolved photon structure. The principles of a photon collider are reviewed. In this thesis, the simulation tools for the simulation of the cross section of ! bb collision are developed. After that, the method for determination of the uncertainties of cross section is described. A new set of PDFs to explore these uncertainties is produced. The result of the simulation of the cross section and the calculation for the uncertainties of the cross section is presented and discussed in detailed.
M.S. in Physics, July 2017
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STUDIES IN NONEQUILIBRIUM STATISTICAL MECHANICS
Title
STUDIES IN NONEQUILIBRIUM STATISTICAL MECHANICS
Creator
Wang, Huichao
Date
2013-05-08, 2013-05
Description
This thesis gives a brief outline of how the microscopic representation enters into a good description of the elasticity of a fluid. We first...
Show moreThis thesis gives a brief outline of how the microscopic representation enters into a good description of the elasticity of a fluid. We first introduce the hydrodynamics by three continuity equations. Due to its macroscopic background, we point out its limitation that it does not fit well with the elastic behavior of the fluid. Therefore we introduce the microscopic description of the system. In order to connect the elasticity which is obviously involved in the non-equilibrium state of a fluid, we discuss how non-equilibrium mechanics could be related to equilibrium mechanics by the assumption that the system is not far away from equilibrium. Under this assumption, an analysis of equilibrium mechanics is necessary, and combining with the microscopic representation, we derive the generalized Langevin equation as an equation of motion of the momentum current, which is endowed with the elastic property, consistent with observations of the fluid.
M.S. in in Physics, May 2013
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FINITE ELEMENT ANALYSIS OF HIGH HEAT LOAD DEFORMATION AND MECHANICAL BENDING CORRECTION OF A BEAMLINE MIRROR FOR THE APS UPGRADE
Title
FINITE ELEMENT ANALYSIS OF HIGH HEAT LOAD DEFORMATION AND MECHANICAL BENDING CORRECTION OF A BEAMLINE MIRROR FOR THE APS UPGRADE
Creator
Goldring, Nicholas
Date
2017, 2017-07
Description
The impending Advanced Photon Source Upgrade (APS-U) will introduce a hard x-ray source that is set to surpass the current APS in brightness...
Show moreThe impending Advanced Photon Source Upgrade (APS-U) will introduce a hard x-ray source that is set to surpass the current APS in brightness and coherence by two to three orders of magnitude. To achieve this, the storage ring light source will be equipped with a multi-bend achromat (MBA) lattice [1]. In order to fully exploit and preserve the integrity of new beams actualized by upgraded storage ring components, improved beamline optics must also be introduced. The design process of new optics for the APS-U and other fourth generation synchrotrons involves the challenge of accommodating unprecedented heat loads. This dissertation presents an ex-situ analysis of heat load deformation and the subsequent mechanical bending correction of a 400 mm long, grazing-incidence, H2O side-cooled, reflecting mirror subjected to x-ray beams produced by the APS-U undulator source. Bending correction is measured as the smallest rms slope error, σrms, that can be resolved over a given length of the heat deformed geometry due to mechanical bending. Values of σrms in the <0.1 µrad regime represent a given mirror length over which incident x-ray beams from modern sources can be reflected without significant loss of quality [2, 3]. This study assumes a perfectly flat mirror surface and does not account for finish errors or other contributions to σrms beyond the scope of thermal deformation and elastic bending. The methodology of this research includes finite element analysis (FEA) employed conjointly with an analytical solution for mechanical bending deflection by means of an end couple. Additionally, the study will focus on two beam power density profiles predicted by the APS-U which were created using the software SRCalc [4]. The profiles account for a 6 GeV electron beam with second moment widths of 0.058 and 0.011 mm in the x- and y- directions respectively; the electron beam is passed through a 4.8 m long, 28 mm period APS-U undulator which produces the x-ray beam incident at a 3 mrad grazing angle on the flat mirror surface for both cases. The first power density profile is the most extreme case created by the undulator at it’s closest gap with a critical energy of 3 keV (ky=2.459); the second profile is generated for the case in which the undulator is tuned to emit at 8 keV (ky=1.026). The 3 keV case is of particular interest as it represents one of the most intense peak heat loads predicted to be incident on first optics at the APS-U. The FEA results revealed that the deflection due to the 3 keV heat load yields a 10.9 µrad rms slope error over the full mirror length. The projected correction via the elastic bending of the substrate yields a 0.10 µrad σrms within the center longitudinal 300 mm. The FEA also predicts that the 8 keV heat load deflection can be corrected to a σrms of 0.11 µrad within the center 300 mm from 1.50 µrad over the entire length. Attempts to optimize the end couple to correct over the entire 400 mm mirror length were unable to resolve the heat load deflection rms slope error to within a < 0.1 µrad value for either case. However, if a larger corrected surface is required, a longer mirror can be implemented so as to absorb the heat load of a larger beam than necessary which can then be cut by an aperture to the desired size and energy range.
M.S. in Physics, July 2017
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SMALL MODULAR NUCLEAR REACTORS: LEARNING AND PRODUCTION
Title
SMALL MODULAR NUCLEAR REACTORS: LEARNING AND PRODUCTION
Creator
Kotlyarevsky, Arnold
Date
2013, 2013-07
Description
Small Modular Nuclear Reactors o er a new alternative to carbon based energy sources in the energy market of the near future. Understanding...
Show moreSmall Modular Nuclear Reactors o er a new alternative to carbon based energy sources in the energy market of the near future. Understanding the economic forces driving the industrial manufacturing process is crucial to determining the viability of SMRs. This study is a continuation of research that developed a parametric model and initial production cost estimates for a generic 100MWe SMR integrated reactor vessel. The primary goal of this study was to characterize the learning rates, lot sizes, and optimum production of SMR IRVs using the parametric model and the initial cost estimates. Three separate models were developed based on increasing levels of learning transfer: no learning transfer, partial learning transfer, and full learning transfer. Models with no learning transfer and full learning transfer bounded the values for the learning curve expected for IRV manufacture. A model with a partial transfer of learning yielded production cost estimates of $312.2 million. Production of an SMR IRV based on this model is expected to see a learning rate 95.5%. Using the information from the other two models, the expected learning rate for IRV production is expected to fall between 93.3% and 99.1% Simulations of lot sizes of 1 to 12 were conducted to determine the manufacturing lot size that optimizes the factory setting. An optimum con guration of 5 units per lot was determined to be the minimum. However, the lot size is recommended to be increased to 6 units to withstand the possibility of cancellation. In this con guration, the average unit cost is $262 million, with a learning rate of 98.1%. Another important result indicates that optimum manufacturing outcomes are not necessarily correlated with higher levels of learning. Production in larger lot sizes is bene cial, especially for components that are few in number, like the pressure vessel.
M.S. in Physics, July 2013
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Leader-Member Exchange as A Mediator Between Negative Affectivity and Work-Family Conflict
Title
Leader-Member Exchange as A Mediator Between Negative Affectivity and Work-Family Conflict
Creator
Pugliese, Stephanie
Date
2012-04-11, 2012-05
Description
The purpose of this study was to investigate the relationship between work-family conflict, negative affectivity, and leader-member exchange....
Show moreThe purpose of this study was to investigate the relationship between work-family conflict, negative affectivity, and leader-member exchange. Survey data was collected from a sample of union employees (n = 358). As hypothesized, leader-member exchange significantly mediated the relationship between negative affectivity and work interfering with family conflict (WIF). Contrary to prediction, leader-member exchange did not mediate the relationship between negative affectivity and family interfering with work conflict (FIW). Discussion of results and implications for practice are provided. In conclusion, this study highlights the importance of leaders in helping employees manage work-family conflict.
M.S. in Psychology, May 2012
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P-DOPED STRONTIUM TITANATE GROWN USING TWO TARGET PULSED LASER DEPOSITION FOR THIN FILM SOLAR CELLS
Title
P-DOPED STRONTIUM TITANATE GROWN USING TWO TARGET PULSED LASER DEPOSITION FOR THIN FILM SOLAR CELLS
Creator
Man, Hamdi
Date
2015, 2015-12
Description
Thin-film solar cells made of Mg-doped SrTiO3 (STO) p-type absorbers are promising candidates for clean energy generation. This material shows...
Show moreThin-film solar cells made of Mg-doped SrTiO3 (STO) p-type absorbers are promising candidates for clean energy generation. This material shows p-type conductivity and also demonstrates reasonable absorption of light. In addition, p-type SrTiO3 can be deposited as thin films so that the cost can be lower than the competing methods. In this work, Mg:SrTiO3 (Mg:STO) thin-films were synthesized and analyzed in order to observe their potential to be employed as the base semiconductor in photovoltaic applications. Mg:STO thin-films were grown with pulsed laser deposition (PLD) using a frequency quadrupled Yttrium Aluminum Garnet (YAG) laser and with a substrate that was heated by back surface absorption of infrared (IR) laser light. The samples were characterized using X-ray photoelectron spectroscopy (XPS) and it was observed that Mg atoms were incorporated in the STO films. Reflection high energy electron diffraction (RHEED) spectroscopy proved that the thin films were polycrystalline. Calculations showed that the lattice constant of Mg:STO/SSF is slightly greater than that of STO/SSF, therefore, the conservation of the characteristic ring pattern for STO suggests of doping by substitution, which is consistent with the examples in literature. Kelvin Probe work function measurements indicated that the work function of the films were 4.167 eV after annealing. EDS spectroscopy showed that Mg was present in the thin films.
M.S. in Physics, December 2015
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