Physics Commons^™

Strontium Monoxide Measurements In Methane-Air Flames, Bobby J. Wimberly

Masters Theses

The spectroscopy of alkaline earth metal compounds has been an area of active research for several decades. This is at least in part stimulated by the application of these compounds to practical areas ranging from technology to medicine. The use of these compounds in the field of pyrotechnics was the motivation for a series of flame emission spectroscopy (FES) experiments with strontium containing compounds. Specifically, strontium monoxide (SrO) is studied as a candidate radiator for the diagnostic of methane-air flames.

SrO emissions have been observed in flames with temperatures in the range of 1200-1600-K for two compounds: strontium hydroxide and …

Installation And Alignment Of The N3he Experiment, Eric Lee Plemons

Masters Theses

The n3He experiment is designed to probe the hadronic weak interaction by measuring the parity violating asymmetry between the spin of incoming neutrons and the momentum of outgoing protons following the nuclear break up of a helium three upon absorbing a neutron. Cold neutrons from the SNS are first polarized then allowed to impact a target chamber filled with helium three where the reaction occurs. Energetic particles resulting from the nuclear breakup ionize the helium three gas and are thereby detected as currents by an array of signal wires within the target chamber. In order to make a statistics limited …

Validation Of Argon From Underground Sources For Use In The Darkside-50 Detector, Thomas R. Alexander

Masters Theses

Liquid argon is an attractive target for dark matter searches due to its low cost and exemplary event discrimination. However, atmospherically derived argon contains the beta-emitter 39Ar which confounds the growth of dual-phase time projection chamber (TPC) style detectors to the ton-scale. The DarkSide Collaboration seeks to bypass this limitation by extracting argon from deep underground, from a location known to contain significantly less 39Ar than atmospherically derived argon. This thesis will summarize the e orts taken to produce the first batch of underground argon, focusing on the first operation of the underground argon in a dual-phase TPC to validate …

Bayesian Model Selection And Parameter Estimation For Gravitational Wave Signals From Binary Black Hole Coalescences, Alexander L. Lombardi

Masters Theses

In his theory of General Relativity, Einstein describes gravity as a geometric property of spacetime, which deforms in the presence of mass and energy. The accelerated motion of masses produces deformations, which propagate outward from their source at the speed of light. We refer to these radiated deformations as gravitational waves. Over the past several decades, the goal of the Laser Interferometer Gravitational-wave Observatory (LIGO) has been the search for direct evidence of gravitational waves from astrophysical sources, using ground based laser interferometers. As LIGO moves into its Advanced era (aLIGO), the direct detection of gravitational waves is inevitable. With …

The Cms Pixel Luminosity Telescope Browser Interface, Mark Miller Foerster

Masters Theses

The search for and detailed study of new particles and forces with the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) of CERN is fundamentally dependent on the precise measurement of the rate at which proton-proton collisions produce any particles, the so-called luminosity. For the discovery of the Higgs candidate in 2012 the relative precision of this quantity was about 2.5%. To be able to observe deviations from Standard Model predictions for decay rates of this particle and others which can hint to new phenomena the targeted luminosity uncertainty is about 1%. Therefore, a new device, the …

Diatomic Carbon Measurements With Laser-Induced Breakdown Spectroscopy, Michael Jonathan Witte

Masters Theses

In this thesis, investigation of well-known carbon Swan spectra is of primary interest. Combustion processes and/or explosion of hydrocarbon fuels cause occurrence of the Swan band system that originates from diatomic carbon. Physical characteristics of low-temperature stars and the interstellar medium can also reveal the Swan bands. The diatomic carbon molecule shows that its lowest rotational levels are sensitive to temperature variation, and higher rotational levels are sensitive to the surrounding gas density and the radiation field. In addition, carbon is a crucial element for life and is the 4th most abundant element; therefore, it is important to ascertain accurately …

Mass Table Calculations With Nuclear Density Functional Theory, Noah Watson Birge

Masters Theses

To better understand nuclei and the strong nuclear force, it is useful to analyze global nuclear properties and trends across the nuclear chart. To this end, we utilized Nuclear Density Functional Theory with Skyrme Energy Density Functionals in conjunction with high-performance computing to perform large-scale mass table calculations for even-even nuclei. Using the binding energy, pairing gap, root-mean-square radius, and deformation data from these tables we were able to analyze the two-proton and two-neutron drip lines, neutron skin depth, two-proton radioactivity, and the effect of nuclear deformation on mass filters. We used numerous energy density functionals to assess the statistical …

Phase Dynamics Of Locset Control Methodology, Brendan Neschke

Masters Theses

Single-mode fiber amplifiers produce diffraction-limited beams very efficiently. Maximum beam intensity requires that an array of these amplifiers have their beams coherently combined at the target. Optical path differences and noise adversely affect beam quality. An existing closed loop phase control methodology, called the locking of optical coherence by single-detector electronic-frequency tagging (LOCSET), corrects phase errors in real time by electronically detecting path length differences and sending signals to lithium niobate phase adjusters. Broadening the line-width using “jitter” of the input signal can increase the output power of an individual amplifier by suppressing nonlinearity. The system dynamics of LOCSET are …

Catalytic Methane Dissociative Chemisorption Over Pt(111): Surface Coverage Effects And Reaction Path Description, Inara Colon-Diaz

Masters Theses

Density functional theory calculations were performed to study the dissociative chemisorption of methane over Pt(111) with the idea of finding the minimum energy path for the reaction and its dependence on surface coverage. Two approaches were used to evaluate this problem; first, we used different sizes of supercells (2x2, 3x3, 4x4) in order to decrease surface coverage in the absence of pre-adsorbed H and CH₃ fragments to calculate the energy barriers of dissociation. The second approach uses a 4x4 unit cell and surface coverage is simulated by adding pre-absorbed H and CH₃ fragments. Results for both approaches show …