Physics Commons^™

Could Alice Find The Elusive Higgs?, Tyler Williams

Physics

The Higgs boson is the theoretical mechanism for creating the mass of particles. Although it has never been seen, the CERN Large Hadron Collider (LHC) is the most likely place for it to be created in the laboratory. The ALICE (A Large Ion Collider Experiment) detector is focused on the study of heavy ion collisions at the LHC and was not designed to find the Higgs boson; however, there is a chance it could be detected there. Although the luminosity (collision rate) for PbPb collisions is much lower than that for pp collisions, PbPb collisions have a higher probability to …

Collisional Dynamics Of The Cesium D1 And D2 Transitions, Greg A. Pitz

Theses and Dissertations

The collisional dynamics of the 6²P levels in cesium have been studied utilizing steady state laser absorption and laser induced florescence techniques. In addition the production of a blue beam produced by two photon absorption has been observed in potassium. The collisional broadening rate for cesium, λ_L, for He, Ne, Ar, Kr, Xe, N₂, H₂, HD, D₂, CH₄, C₂H₆, CF₄, and ³He are 24.13, 10.85, 18.31, 17.82, 19.74, 16.64, 20.81, 20.06, 18.04, 29.00, 26.70, 18.84, and 26.00 MHz/torr, respectively for the …

Laser Demonstration And Performance Characterization Of An Optically Pumped Alkali Laser System, Clifford V. Sulham

Theses and Dissertations

Diode Pumped Alkali Lasers (DPALs) offer a promising approach for high power lasers in military applications that will not suffer from the long logistical trails of chemical lasers or the thermal management issues of diode pumped solid state lasers. This research focuses on characterizing a DPAL-type system to gain a better understanding of using this type of laser as a directed energy weapon. A rubidium laser operating at 795 nm is optically pumped by a pulsed titanium sapphire laser to investigate the dynamics of DPALs at pump intensities between 1.3 and 45 kW/cm². Linear scaling as high as …

All Solid-State Mid-Ir Laser Development, Nonlinear Absorption Investigation And Laser-Induced Damage Study, Torrey J. Wagner

Theses and Dissertations

In this research, nonlinear optical absorption coefficients and laser-induced damage thresholds are measured in Ge and GaSb, which are materials that are used in IR detectors. Using a simultaneous fitting technique to extract nonlinear absorption coefficients from data at two pulse widths, two-photon and free-carrier absorption coefficients are measured in Ge and GaSb at 2.05 and 2.5 μm for the first time. At these wavelengths, nonlinear absorption is the primary damage mechanism, and damage thresholds at picosecond and nanosecond pulse widths were measured and agreed well with modeled thresholds using experimentally measured parameters. The damage threshold for a single-layer Al …

Bottom Quark Detection With The Electromagnetic Calorimeter At Alice, Christopher Ryan Brown

Physics

Bottom quarks are one of the easiest ways to observe quark flow in a quark gluon plasma. For this reason, it is advantageous in a detector to have superb capabilities at detecting bottom quarks through their decay products and interactions. This paper will provide an overview of bottom quark behavior in a quark gluon plasma, as well as methods used to detect this behavior. Once this has been established, an overview of the heavy ion physics at the Large Hadron Collider (LHC), and particularly A Large Ion Collider Experiment (ALICE), will be discussed. It will then be argued that the …

Experimental Investigation Of A Non-Thermal Atmospheric Pressure Plasma Jet, Asma Begum

Electrical & Computer Engineering Theses & Dissertations

The main objective of this dissertation is to understand the formation of the plasma jet from the plasma pencil, and the propagation of the plasma jet in the ambient atmosphere where the effect of the external electric field is almost zero. Before investigating the formation and propagation phenomenon of the plasma jet, common physical properties of plasma jets are determined by using the imaging technique and optical emission spectroscopy. The first goal of this dissertation is to establish the laminar helium gas flow channel through a plasma pencil.

The formation position, formation time, and the criterion of the plasma jet …

Investigation Of Track-Cluster Matching Vs Track-Cell Matching In The Alice Detector At Cern, Kevin Coulombe

Physics

The ALICE (A Large Ion Collider Experiment) Experiment is a detector that is one of four stationed at the CERN Large Hadron Collider. The goal of ALICE is to investigate the properties of the quark-gluon plasma, a new form of matter which only existed during the first microsecond of the Universe. ALICE measures the aftermath of the collision of two lead ions. Some information detected is the trajectory of the particles traveling through the tracking detectors and energy deposited in the calorimeters. Both the tracks and energy are required to determine the identities of the various particles as they travel …

Determination Of Energy Level Excitation States Of Time Dependent Optogalvanic Signals In A Discharge Plasma, Michael Christopher Blosser

Undergraduate Honors Thesis Collection

When tuning a laser between two excited energy levels of the atoms in a discharge plasma, the discharge current will temporarily be disturbed. This disturbance or change in current is the optogalvanic effect (OGE). The fundamental goal of this project is to determine the exponential rates in the time-dependent OGE signals. These rates are related to the collision rates for the atoms in the plasma. The OGE data will be experimentally recorded, fitted, and analyzed to extract the exponential rates related to the energy levels of the atom in gas in the discharge lamp.

Numerical Investigation Of Statistical Turbulence Effects On Beam Propagation Through 2-D Shear Mixing Layer, James C. Bowers

Theses and Dissertations

A methodology is developed for determining the validity of making a statistical turbulent approach using Kolmogorov theory to an aero-optical turbulent ow. Kolmogorov theory provides a stochastic method that has a greatly simplified and robust method for calculating atmospheric turbulence effects on optical beam propagation, which could simplify similar approaches to chaotic aero-optical flows. A 2-D laminar Navier-Stokes CFD Solver (AVUS) is run over a splitter plate type geometry to create an aero-optical like shear mixing layer turbulence field. A Matlab algorithm is developed to import the flow data and calculates the structure functions, structure constant, and Fried Parameter ( …

Simulation Of A Diode Pumped Alkali Laser, A Three Level Numerical Approach, Shawn W. Hackett

Theses and Dissertations

This paper develops a three level model for a continuous wave diode pumped alkali laser by creating rate equations based on a three level system. The three level system consists of an alkali metal vapor, typically Rb or Cs, pumped by a diode from the ²S_1/2 state to the ²P_3/2 , a collisional relaxation from ²P_3/2 to ²P_{1/ 2} , and then lasing from ²P_1/2 to ²S_1/2 . The hyperfine absorption and emission cross sections for these transitions are developed in detail. Differential equations for intra-gain pump attenuation …

Mission Analysis And Design For Space Based Inter-Satellite Laser Power Beaming, Nicholas M. Keller

Theses and Dissertations

This research effort develops an interdisciplinary design tool to optimize an orbit for the purpose of wirelessly beaming power from the International Space Stations (ISS) Japanese Experimental Module Exposed Facility (JEM/EF) to a target satellite. For the purpose of this initiative, the target satellite will be referred to as FalconSAT6, a reference to the proposed follow-on satellite to the U.S. Air Force Academy’s (USAFA) FalconSAT5 program. The USAFA FalconSAT program provides cadets an opportunity to design, analyze, build, test and operate small satellites to conduct Department of Defense (DoD) space missions. The tool developed for this research is designed to …

Accelerated Lattice Boltzmann Method For Colloidal Suspensions Rheology And Interface Morphology, Hassan Farhat

Wayne State University Dissertations

ABSTRACT

ACCELERATED LATTICE BOLTZMANN MODEL FOR COLLOIDAL SUSPENSIONS RHEOLOGY AND INTERFACE MORPHOLOGY

by

HASSAN FARHAT

July 2010

Advisor: Dr. Singh Trilochan

Co-Advisor: Dr. Joon Sang Lee

Major: Mechanical Engineering

Degree: Doctor of Philosophy

Colloids are ubiquitous in the food, medical, cosmetic, polymer, water purification and pharmaceutical industries. Colloids thermal, mechanical and storage properties are highly dependent on their interface morphology and their rheological behavior.

Numerical methods provide a cheap and reliable virtual laboratory for the study of colloids. However efficiency is a major concern to address when using numerical methods for practical applications.

This work introduces the main building-blocks for …

Comparison Of Full-Wave And Ray-Tracing Analysis Of Mode Conversion In Plasmas, Yanli Xiao

Dissertations, Theses, and Masters Projects

This dissertation reports on the first direct comparison between the results of ray-based and full-wave calculations for mode conversion in plasma. This study was motivated by the modular method originally developed by Ye and Kaufman to treat a magnetosonic wave crossing a cold minority-ion gyroresonance layer. We start with the cold plasma fluid model and introduce a system of evolution equations for electrons and two ion species: deuterium and hydrogen. We first study this system of equations for uniform plasma by Fourier methods, which gives the dispersion relations. We discuss how the traditional approach---which eliminates all other dynamical variables in …