Physical Sciences and Mathematics Commons^™

The Variation Of Hydrogen Concentration In Ni/Mgh Thin Film With Temperature, Rex Nyadaufe Taibu

Masters Theses

The thermal stability of Ni/MgH thin film deposited on Si substrate by Unbalanced Magnetron Physical Vapor Deposition has been investigated using Ion Beam analysis (DBA) techniques. Rutherford Backscattering Spectrometry (RBS) and Non-Rutherford Backscattering Spectrometry (NRBS) have been used to find the composition of Magnesium, Nickel and Oxygen. Elastic Recoil Detection Analysis (ERDA) has been used to determine the concentration of hydrogen at each level of heating. Heating was done in the Ultra High Vacuum (UHV) environment using a non gassy button heater. Ni/MgH sample had lost most of its hydrogen after being heated to a temperature of about 125°C in …

Research Report 2012, College Of Arts And Sciences

Physics Research Reports

• Cover Designs
• Introduction
• Astronomy
• Atomic and Molecular Physics
• Condensed Matter Physics
• Physics Education
• Research and Public Lectures at WMU
• Personnel January 1- December 31, 2012

Newsletter, Fall 2011, College Of Arts And Sciences

Physics Newsletter

Contents from Vol 8, No. 1 of the Newsletter for Friends of the Western Michigan University Department of Physics:

• News
• Staff News
• Faculty News
• Alumni News
• Student News
• Department of Physics Roster

Modeling Of A Photonic Crystal Waveguide Modes With The Fdtd Method, Buddhi Rai

The Hilltop Review

The electromagnetic modes are investigated using a simple 1D implementation of the FDTD numerical algorithm to a model of 1D photonic crystal. The fields E_z and H_y are simulated along the x-axis, the propagation direction. Source implementation and the effects of various boundary conditions such as ABC, Mur on TF-SF fields are investigated. Of particular focus in this paper is, for example, on investigating the guided and/or radiation modes at a stop band frequency of the photonic crystal formed of linear and Kerr nonlinear media. Such structures exhibit interesting transmission and reflection properties that make them suitable for …

K-X-Ray Emission In Fast O5+ On Ar Collisions, Tamer Elkafrawy

Research and Creative Activities Poster Day

The goal of the present work is to observe x-rays from oxygen for the purpose of investigating resonant-transfer and excitation (RTE) [1], and projectile and target x-ray emission resulting from inner-shell capture. Projectile energies in the range 5-25 MeV will be examined to investigate RTE for heavy targets [2,3].

Newsletter, Spring 2011, College Of Arts And Sciences

Physics Newsletter

Contents of Vol 7, No. 2 of the Newsletter for Friends of the Western Michigan University Department of Physics:

• News
• Staff News
• Alumni News
• Student News
• Department of Physics Roster
• Feedback Form

Research Report 2011, Western Michigan University

Physics Research Reports

• Introduction
• From the Chairperson
• Atomic and Molecular Physics
• Condensed Matter Physics
• Nuclear Physics
• Physics Education
• Research and Public Lectures at WMU
• Personnel January 1- December 31, 2011

Relativistic R-Matrix Theory, Janina Grineviciute

Dissertations

We have developed a relativistic coupled{channel reaction theory in which binary break-up channels satisfy a relative Dirac equation. This theory is developed by extending the R-matrix formalism of Lane and Thomas to the relativistic case and implementing the Dirac oscillator basis. The motivation for this project is testing po- tentials for the dense matter calculations and generating relativistic wave functions for the nal states in the knockout reactions. As an example of the formalism we have calculated observables for the proton scattering on light-to-medium weight nuclei in the relativistic impulse approximation using the relativistic Love-Franey amplitudes of Horowitz. The R-matrix …

Commissioning Of The Helical Orbit Spectrometer: A New Device For Measuring Nuclear Reactions In Inverse Kinematics, Jonathan C. Lighthall

Dissertations

The Helical Orbit Spectrometer (HELIOS) at Argonne National Laboratory is the first implementation of a radical new concept for measuring nuclear reactions. Direct nuclear transfer reactions are powerful tools for studying the properties of the atomic nucleus. A traditional example is the neutron-transfer reaction (d ,p), wherein an accelerated beam of deuterons d bombards a heavy target. The incoming deuteron transfers a neutron to the target nucleus and the outgoing proton p is detected to study the properties of the residual heavy nucleus. A new frontier of nuclear reaction studies involving short-lived exotic nuclei—which are unsuitable for use …

Electron Transmission Characteristics And The Production Of Narrow Beams Using Glass Optics, Buddhika Senarath Dassanayake

Dissertations

Transmission of electrons through an insulating single cylindrically-shaped glass capillary of microscopic dimension has been investigated. Samples made with Borosilicate glass (PYREX 7740) were subjected to bombardment of 300-1000 eV electrons. Transmitted electrons were analyzed using a parallel-plate spectrometer coupled to a channel electron multiplier.

The transmitted electron intensity was found to decrease with increasing sample tilt angle relative to the direction of the primary beam. Two regions of transmission were found: direct where there is no interaction of the beam with the inner capillary wall, and indirect where the beam does interact with the wall. The rate of transmission …

Proton Capture Reactions And Network Calculations On 46Ti, 64Zn, 114Sn And 116Sn Relevant To The Rp-Process, Ravin S. T. Kodikara

Dissertations

The rp-process makes an important contribution to the stellar nucleosynthesis by producing many of the light proton rich nuclei. Successive proton captures on seed nuclei followed by occasional β-decays and electron captures are the key features of this mechanism. For a detailed rp-process analysis, proton capture cross sections and reaction rates are essential. However, the lack of experimental data forces the researcher to largely depend on statistical model predictions.

This dissertation research is an attempt to investigate the proton captures of four particular nuclides; ⁴⁶Ti, ⁶⁴Zn, ¹¹⁴Sn and ¹¹⁶Sn. At Western Michigan University Van de Graaff …

Dielectronic Recombination For Aluminum-Like Ions And Photoabsorption Cross Sections For Magnesium Ions At The K-Edge, Shahin Ahmed Abdel-Azim Abdel Naby

Dissertations

Accurate and reliable recombination data are needed for modeling the ions in the finitedensity plasmas that may take place in solar flares and in divertors of magnetically confined fusion devices such as the International Thermonuclear Experimental Reactor (ITER). Dielectronic recombination (DR) is the dominant recombination mechanism in photoionized and collisionally-ionized plasmas. DR rate coefficients for M-shell argon ions have been calculated using a configuration-average approach. DR rate coefficients for the aluminumlike isoelectronic sequence are instead calculated using the state-of-the-art multiconfiguration Breit-Pauli (MCBP) atomic structure and collision code AUTOSTRUCTURE. Good agreement is obtained with the measurements from the Heidelberg heavy-ion Test …

Inner-Shell Photodetachment Of Transition Metal Negative Ions, Ileana Dumitriu

Dissertations

This thesis focuses on the study of inner-shell photodetachment of transition metal negative ions, specifically Fe¯ and Ru¯. Experimental investigations have been performed with the aim of gaining new insights into the physics of negative atomic ions and providing valuable absolute cross section data for astrophysics. The experiments were performed using the X-ray radiation from the Advanced Light Source, Lawrence Berkeley National Laboratory, and the merged-beam technique for photoion spectroscopy.

Negative ions are a special class of atomic systems very different from neutral atoms and positive ions. The fundamental physics of the interaction of transition metal negative ions with photons …

Newsletter, Spring 2010, College Of Arts And Sciences

Physics Newsletter

Contents from Vol 7, No. 1 of the Newsletter for Friends of the Western Michigan University Department of Physics:

• President Emeritus Diether Haenicke
• Faculty News
• Staff Highlights
• Annual Student Awards
• Alumni News
• Accelerator Laboratory
• Department of Physics Roster
• Feedback Form

Research Report 2010, College Of Arts And Sciences

Physics Research Reports

• Introduction
• From the Chairperson
• Astronomy
• Atomic and Molecular Physics
• Condensed Matter Physics
• Physics Education
• Research and Public Lectures at WMU
• Personnel January 1-December 31, 2010

Theoretical Study Of Localized Surface Plasmons Of Metal Nanoparticles, Clusters And Embedded Metal Nanoparticles In Matrices, Masoud Shabani Nezhad Navrood

Dissertations

Localized surface plasmons resonances (LSPRs) in metallic nanoparticles (NPs) arise from the interactions between incident light and conduction electrons and have attracted enormous research interest in recent years both for their fundamental nature as well as applications in interdisciplinary areas of sciences such as biological imaging, plasmonic photo-thermal therapy, photovoltaics, and plasmonic sensors. LSPRs are strongly localized and depend on the shape, size, the composition of the NPs, the polarization direction of the incident light, refractive index (RI) of the surrounding medium as well as on the chemical environment that surrounded NPs. Although significant research has progressed both theoretically and …

Photoionization Of Rare Gas Clusters, Huaizhen Zhang

Dissertations

This thesis concentrates on the study of photoionization of van der Waals clusters with different cluster sizes. The goal of the experimental investigation is to understand the electronic structure of van der Waals clusters and the electronic dynamics. These studies are fundamental to understand the interaction between UV-X rays and clusters. The experiments were performed at the Advanced Light Source at Lawrence Berkeley National Laboratory. The experimental method employs angle-resolved time-of-flight photoelectron spectrometry, one of the most powerful methods for probing the electronic structure of atoms, molecules, clusters and solids.

The van der Waals cluster photoionization studies are focused on …

Entanglement Perturbation Theory For Antiferromagnetic Spin Chains, Lihua Wang

Dissertations

In this dissertation, we use the recently developed Entanglement Perturbation Theory (EPT) to solve antiferromagnetic spin chain problems, for both spin 1/2 and spin 1. We firs use EPT-g (EPT algorithm for ground state) to get the ground state properties. We calculated precisely energies, magnetization and spin-spin correlations. The precision of the long range spin-spin correlation functions for spin 1/2 chains is unprecedented. Due to its special structure, we also use EPT-g to calculate the firs excited state properties for spin 1 chains. Hence we plotted the phase diagram for spin 1 xxz chains. Also a generalization of EPT (EPT-e) …

Transmission And Guiding Of Fast Electrons Through Insulating Nanocapillaries And Comparison With Ion Guiding, Susanta Das

Dissertations

Transmission and guiding of fast electrons (500 and 1000 eV) through an insulating polyethylene terephthalate nanocapillary foil has been investigated and compared with results for slow highly charged ions. As for slow ions, guiding is attributed to charge-up of the inner walls near the capillary entrance, which, after a characteristic time, electrostatically deflects the traversing ions causing them to be guided through the sample along the capillary axis. The measurements were performed at WMU. Electron guiding is found to decrease faster with both energy and foil tilt angle than for ions. Ions lose negligible energy during the course of guiding, …

Calculations Of K-Shell Fluorescence Yields And Photoabsorption Cross Sections For Carbon Ions At The K-Edge, Muhammet Fatih Hasoglu

Dissertations

The advent of new space missions providing high-precision observations has engendered the need for reliable and precise K-shell atomic data in order to interpret these X-ray spectra. In response to this need, we focused on the calculation of K-shell fluorescence yields for 2 nd -row ions. A secondary project was undertaken in order to treat theoretically the K-shell X-ray absorption processes in carbon ions. These calculated fluorescence yields of 2nd -row ions and theX-ray photoabsorption cross sections of carbon are astrophysically important in determining (1) charge-changing probabilities, such as Auger vs. radiative decay, and (2) chemical abundances of the interstellar …

Oxidation Resistance Studies Of Crain Coatings On 430 Stainless Steel, Kurtis Wickey

Honors Theses

The requirements of low cost and high-cost temperature corrosion resistance for interconnect plates in solid oxide fuel cell stacks has directed attention to the use of metal plates with oxidation resistant coatings. We have investigated the performance of stainless steel plates with homogenous coatings of CrAIN. The coatings were deposited using RF magnetron sputtering, with Ar as a sputtering gas and N as reactive gas. The Cr/A1 composition ratio in the coatings was varied in a combinatorial approach. The coatings were subsequently annealed in air for up to 25 hours at 800°C. The composition of the coated plates and the …

The Physics Of Electron Degenerate Matter In White Dwarf Stars, Subramanian Vilayur Ganapathy

Masters Theses

White dwarfs are the remnant cores of medium and low mass stars with initial mass less than 8 times the mass of our sun. As the aging giant star expels its surface layers as planetary nebulae, the core is exposed as a white dwarf progenitor. The density of matter in white dwarfs is so high that thermal or radiation pressure no longer supports the star against the relentless pull of gravity. The white dwarf is supported by a new kind of pressure known as the degeneracy pressure, which is forced on the electrons by the laws of quantum mechanics. The …

Research Report 2008-2009, College Of Arts And Sciences

Physics Research Reports

• Introduction
• From the Chairperson
• Astronomy
• Atomic Physics
• Condensed Matter Physics
• Nuclear Physics
• Physics Education
• Research and Public Lectures at WMU
• Personnel

Quantum Properties Of Light Emitted By Dipole Nano-Laser, Talal Ghannam

Dissertations

Recent technological advances allow entire optical systems to be lithographically implanted on small silicon chips. These systems include tiny semiconductor lasers that function as light sources for digital optical signals. Future advances will rely on even smaller components. At the theoretical limit of this process, the smallest lasers will have an active medium consisting of a single atom (natural or artificial). Several suggestions for how this can be accomplished have already been published, such as nano-lasers based on photonic crystals and nano wires. In particular, the "dipole nanolaser" consists of a single quantum dot functioning as the active medium. It …

Structure And Excitations In Metal Ammonia Compounds, Xue Wang

Dissertations

This work has two parts. In the first part, inelastic x-ray scattering was used to measure the plasmon excitations in liquid lithium ammonia systems. The measurements were carried out for different metal concentrations, 8 mole per metal (MPM), 10 MPM, 11 MPM, 16 MPM and 20 MPM of temperature 200K. The data were analyzed to determine the plasmon energy and the linewidth as a function of momentum for each metal concentration. Deviations from the random phase approximation (RPA) in the jellium model increase as the concentration is lowered.

In the second part of this work, elastic x-ray scattering was used …

The Effect Of A Skyrme Interaction On Nucleon Induced Reactions, Yingfa Zhang

Masters Theses

The main goal of this Master thesis is the theoretical study of the interaction between a nucleon and a nucleus. This is a fundamental method to study the structure and dynamics of nuclear systems. This thesis concentrates on the study of nucleon scattering on light nuclei, ⁶Li, ⁷Li and ¹⁴N, with the effective interaction M3Y and its modification by adding a Skyrme force. This is the first time the Skyrme interaction has been employed in scattering calculations. From a comparison of the measured differential cross section σ (θ) and the analyzing power Ay (θ) for ⁶Li …

Wireless Passive Surface Acoustic Wave (Saw) Sensing System, Sridevi Krishnamurthy

Dissertations

Due to their small size and ruggedness, Surface Acoustic Wave (SAW) devices have been widely used as part of wireless sensing or identification system especially in inaccessible and inhospitable environments. In addition, SAW devices find widespread applications as filters in communication systems and also as physical, chemical and bio-sensors and ID tags. The passive wireless SAW sensing system mainly consists of a passive SAW sensor and an interrogation unit which sends a burst signal to the SAW sensor and processes the sensor response. Theobjectives of this work were designing, prototyping and fabricating the interrogation unit on a PCB and also …

Physics Department News, June 2007, College Of Arts And Sciences

Physics Newsletter

Contents from Volume 6, Issue 1:

• What’s New at the University
• Faculty Highlights
• Alumni Achievement Awards
• More Alumni News
• Staff Highlights
• Soga Center Opens
• Student News
• Annual Student Awards
• Recent Graduates
• Book Awards
• Department Roster
• Feedback Form

Inelastic X-Ray Scattering Studies On Organic Semiconductors And Organic Superconductors, Chaminda Nalaka Kodituwakku

Dissertations

We have measured electronic excitations and excitons in CuPc polycrystalline and single crystal samples. Measurements on the polycrystalline sample were done with 300 meV resolution and measurements on the single crystal were done using 120 meV resolution. Time dependant density functional theory (TD-DFT) calculations were done on the CuPc molecule to understand the electronic excitations in this system.

Research Report 2007-2008, College Of Arts And Sciences

Physics Research Reports

• Introduction
• From the Chairperson
• Astronomy
• Atomic Physics
• Condensed Matter Physics
• Nuclear Physics
• Physics Education
• Publications
• Dissertations
• Presentations
• Proposals and Grants
• Scholarly Activity
• Personnel