Physics Commons^™

Design Of Film-Substrate Single-Reflection Linear Partial Polarizers, R. M.A. Azzam, A.-R. M. Zaghloul, N. M. Bashara

Electrical Engineering Faculty Publications

The results of a preceding paper [J. Opt. Soc. Am. 65, 1464,(1975)] are viewed from a different angleas providing the basis for the design of film-substrate single-reflection linear partial polarizers (LPP),which also operate as reflection optical rotators. The important characteristics of a comprehensive set of discrete designs of SiO₂-Si LPP’s at λ = 6328 Å are shown graphically.

Polarizer-Surface-Analyzer Null Ellipsometry For Film-Substrate Systems, R. M.A. Azzam, A.-R. M. Zaghloul, N. M. Bashara

Electrical Engineering Faculty Publications

Single-pass polarizer-surface-analyzer null ellipsometry (PSA-NE) can be used to characterize film-substrate systems, provided that the film thickness lies within one of a set of permissible-thickness bands (PTB). For a transparent film on a transparent or absorbing substrate, the PTB structure consists of a small number of finite-bandwidth bands followed by a continuum band that extends from a film thickness of about half the wavelength of light to infinity. We show that this band structure is a direct consequence of the periodicity of the ellipsometric function ρ (the ratio R_p/R_s, of the complex amplitude-reflection coefficients for …

Radiative Lifetime Of The B ²Σˉ State Of Ch, Richard A. Anderson, Jerry Peacher, David M. Wilcox

Physics Faculty Research & Creative Works

The radiative lifetimes of the N'=3 to 15 rotational states of the v'=0 level of the B ²Σ^- state of CH were measured. Emission lines were observed to N'=15, but no lines above this rotational state were observed. This result agrees with previous studies. The lifetimes of all rotational states were between 300 and 400 ns. Previous measurements have indicated that the N'=15 level might have a lifetime as short as 100 ns.

Spin-Flip Inelastic Scattering In 12C(P,P1)12C Near The 9.14 Mev Doublet, Hsing-Tsuen Chen

Masters Theses

No abstract provided.

Ultraviolet Excitation Thermoluminescence Of Lead-Manganese Calcium Carbonate, Dennis Schrope

Masters Theses & Specialist Projects

Calcium carbonate with impurities of lead and manganese have produced measurable thermoluminescence (TL) when excited by ultraviolet (uv) radiation. In this investigation the lead impurities comprise the majority of trapping centers stimulated by uv irradiation. In addition, centers associated with the CO₃groups have been found to be capable of absorbing uv and ultimately producing TL. The 2537 Å mercury line is primarily responsible for stimulating these centers, and the response was found to be linear to 0.6734 joules/cm².

The thernoluminescence response was discovered to be dependent on the concentrations of lead and manganese. However, for a …

High-Frequency Dielectric Measurements On Electro-Optic Single Crystals, J. R. Teague, R. R. Rice, Robert Gerson

Physics Faculty Research & Creative Works

A slotted line was used to measure the high-frequency dielectric constant and loss tangent of several electro-optic crystals useful for wide-band laser modulator applications. Dielectric measurements were made at 0.1, 0.3, 1.0, and 2.0 GHz.

Saturation Effects In A Tunable Coherent Near-Infrared Source, Israel L. Tyler, R. (Ralph) W. Alexander, R. (Robert) J. (John) Bell

Physics Faculty Research & Creative Works

A Saturation Effect in a Tunable Infrared Source Utilizing Four-Wave Parametric Conversion in Potassium Vapor is Reported and is Shown to Be the Result of Parasitic Oscillations. a Hundredfold Increase over Previously Attained Power Levels Has Been Affected Via Elimination of These Oscillations.

Effect Of Uniaxial Stress On The Unstable A1 (To) Phonon In Ferroelectric Gadolinium Molybdate, B.N. Ganguly, Frank G. Ullman, Roger D. Kirby, J.R. Hardy

Roger Kirby Publications

The effect of uniaxial stress along [100] on the unstable A₁ (TO) phonon, 47 cm^-1 at room temperature, in ferroelectric (<159°C) gadolinium molybdate has been studied by Raman scattering at 138, 141, 146, and 155°C. An increase in peak frequency and narrowing of the line shape is observed with increasing stress. The data are analyzed by fitting to a Lorentzian line shape. The force-constant parameter is insensitive to both stress and temperature, whereas the damping constant decreases nonlinearly with stress, approaching an asymptotic value at high stress.

Relaxation Of The Wall-Pinned Magnetization Ringing Mode In Superfluid 3he-B, Richard A. Webb, R. E. Sager, J. C. Wheatley

Faculty Publications

Observations of the wall-pinned mode in ³He-B allow new magnetic relaxation phenomena to be studied. Excepting the quantitative value of the zero-time ringing frequency, comparison of experiment with theory is satisfactory, including a linear dependence of the square of the ringing period on time and a square-root singularity near T_c in the relaxation parameter.

Path-Integral Formulation Of Scattering Theory, Paul Finkler, C. Edward Jones, M. Misheloff

Paul Finkler Papers

A new formulation of nonrelativistic scattering theory is developed which expresses the S matrix as a path integral. This formulation appears to have at least two advantages: (1) A closed formula is obtained for the S matrix in terms of the potential, not involving a series expansion; (2) the energy-conserving δ function can be explicitly extracted using a technique analogous to that of Faddeev and Popov, thereby yielding a closed pathintegral expression for the T matrix. The introduction of the concept of the classical interaction picture provides considerable physical insight into this formulation. This formulation also suggests a successionof improvements …

Nonlinear Parallel Ringing Of Magnetization In Superfluid 3he, Richard A. Webb, R. E. Sager, J. C. Wheatley

Faculty Publications

Experiments based on an analogy to the ac Josephson effect have shown in both ³He-A and ³He-B that a pairing theory of the superfluidity of ³He is essentially correct. Additional observations of parallel ringing are not in agreement with the simple "pendulum models" used to describe nonlinear dynamic magnetic effects.

2P3/2:2P1/2 Partial Photoionization Cross-Section Ratios In The Rare Gases , James A.R. Samson, J.L. Gardner, Anthony F. Starace

Anthony F. Starace Publications

The ²P_3/2:²P_1/2 partial photoionization cross-section ratios have been measured for the rare gases in the ionization continuum and within resonance structure. The wavelength range for this study was from the ²P_1/2 ionization threshold to 304 Å. The ratio of the cross sections was found to be constant over this wavelength range, yielding ratios of 1.54, 1.77, 1.93, and 2.18 for Xe, Kr, Ar, and Ne, respectively. Within resonances, the ratio changed dramatically. Results are illustrated for xenon.

Karate Strikes, Jearl D. Walker

Physics Faculty Publications

Analysis of a forward karate punch is made as an example of collision mechanics. The energy lost to deformation of an opponent is evaluated, and the deformation is shown to be maximized if contact is made when the fist has the greatest speed. In karate fighting the maximum deformation is obtained by focusing a punch to terminate several centimeters inside an opponent’s body. The average impact force is calculated and compared with that neeeded to break a human bone by stressing it beyond its ultimate bending stress value. Similar breaking forces needed for bricks and wooden boards are also computed. …

Technique For Rapid Faraday Susceptibility Measurements, F.R. Szofran, W.L. Burmester, David J. Sellmyer, L.G. Rubin

David Sellmyer Publications

An apparatus is described which permits the rapid acquisition and computer analysis of temperature-dependent Faraday susceptibility data. The apparatus utilizes a relatively inexpensive, three-channel, data-acquisition system. Review of Scientific Instruments is copyrighted by The American Institute of Physics.

Design Of Film—Substrate Single-Reflection Retarders, A.-R. M. Zaghloul, R. M.A. Azzam, N. M. Bashara

Electrical Engineering Faculty Publications

The design steps for film—substrate single-reflection retarders are briefly stated and applied to the SiO₂—Si film—substrate system at wavelength 6328 Å. The criterion of minimum-maximum error of the ellipsometric angle ψ is used to choose angle-of-incidence-tunable designs. Use is made of the (Φ-d) plane (angle of incidence versus thickness) to determine whether a given film—substrate system with known optical properties and film thickness can operate as a reflection retarder and to determine the associated angles of incidence and retardation angles. This leads to the concept of permissible-thickness bands and forbidden gaps for operation of a film—substrate …

Intrinsic Viscosity Of Stiff Dumbbells From Time Correlation Functions, Gerald Wilemski

Physics Faculty Research & Creative Works

The intrinsic viscosity of a suspension of stiff dumbbells is evaluated by a time correlation function method. The required moments of the internal coordinates are calculated directly from the diffusion equation, without explicit evaluation of the Green's function. For the rigid dumbbell, the correct high frequency limit is obtained, disposing of recent doubts over this possibility. The interplay of dumbbell stiffness and shearing frequency is also illustrated.

Relationship Between The Linear Ringing Frequencies In 3he-A And 3he-B Near The Polycritical Point, Richard A. Webb, R. E. Sager, J. C. Wheatley

Faculty Publications

New measurements of parallel ringing in a quasi-ideal geometry for ³He-B near the temperature and pressure of the polycritical point suggest f_B²/f_A²∼5/2, where f_B and f_A are the linear parallel-ringing frequencies at a given temperature near T_c. This result approaches the prediction of theory using the Anderson-Brinkman-Morel and Balian-Werthamer states to describe ³He-A and ³He-B, respectively, and hence the results of Osheroff at melting pressure, but disagrees with earlier observations at pressures near the polycritical point.

Gauge Invariance And Radiative Transition Probabilities, Ian P. Grant, Anthony F. Starace

Anthony F. Starace Publications

The relationship between recommendations of some recent papers on the choice of formula (length, velocity, or acceleration type) for calculating radiative transition probabilities is clarified.

Synthetic Analogs Of Active Sites Of Iron-Sulfur Proteins: Bis (O-Xylyldithiolato) Ferrate (Iii) Monoanion, A Structurally Unconstrained Model For The Rubredoxin Fe-S4 Unit, R. W. Lane, James A. Ibers, Richard B. Frankel, R. H. Holm

Physics

To complete the set of synthetic analogs of the three recognized types of active sites in iron-sulfur redox proteins, the compound (Et₄N)[Fe((SCH₂)₂C₆H₄)₂], derived from o-xylyl-α,α'-dithiol, has been prepared and its structure has been determined by x-ray diffraction. The bischelate anion contains a near-tetrahedral Fe(III)-S₄ coordination unit with small rhombic distortions and all Fe-S bond distances in the range 2.252-2.279 Å. Its electronic properties have been partially characterized by measurement of electronic absorption, paramagnetic resonance, Mössbauer spectra, and magnetic susceptibility. The analog, as …

17th Annual Rocky Mountain Spectroscopy Conference

Rocky Mountain Conference on Magnetic Resonance

Final program and abstracts from the 17th annual meeting of the Rocky Mountain Spectroscopy Conference, sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, August 4-8, 1975.

Teaching-The Purpose Of Repeatable Testing: Response To Comment Of J. D. Edmonds, D.E. Golden, Robert Fuller, D.D. Jensen

Robert G. Fuller Publications

It is not clear that the comment "Grading and Regrading"' has very much to do with our article.' The comment seems rather to be a nostalgic statement recalling the good old days when with glee we cracked the whip and the students either shaped up or shipped out.

Our purpose in doing repeatable testing was not to become a "do your own thing" force, to raise everyone's grades, to "achieve well defined educational objectives" like teaching the solution to the inclined plane problem, to do away with certification, and most definitely our purpose was not to replace teachers with computer-programmed …

Effect Of Elliptically Polarized Light On The Angular Distribution Of Photoelectrons, James A. R. Samson, Anthony F. Starace

Anthony F. Starace Publications

The angular distribution of photoelectrons predicted for elliptically polarized light is shown to be the same as that predicted for partially polarized light having incoherent perpendicular electric field components equal to the electric field components along the major and minor axes of the ellipse.

Includes Corrigendum from J. Phys. B: Atom. Molec. Phys. 12:23 (1979), p. 3993.

Sensitivity Of A Gas Filter Correlation Instrument To Variations In Atmospheric Profile And Earth Surface Temperatures, Joseph C. Casas

Physics Theses & Dissertations

The Gas Filter Correlation Radiometer Analyzer (GFCR), in application to the remote sensing of trace gases in the atmosphere, is potentially limited by the sensitivity of the measured upwelling thermal radiation to surface temperature and atmospheric temperature conditions. This study has been carried out to examine the principles of operation of the GFCR Analyzer and to obtain quantitative estimates of the errors produced in GFCR Analyzer measurements of CO (4.6μ), S02 (8.6μ), NH3 (11.0μ), and CH4 (8.1μ) resulting from uncertainties in the atmospheric temperature profile and ground temperature.

A simple mathematical prototype GFCR Analyzer was assumed. A line-by-line atmospheric radiative …

The Determination Of Double Mode Variable Star Periods, Arne A. Henden

Physics & Astronomy ETDs

ABSTRACT

The problem of determining the periods of objects oscillating in one or more modes is discussed. Although the methods described are applicable to many different kinds of objects and observations, the discussion has been limited to double mode Cepheid stars.

Two methods of solution are followed in detail. An autocorrela­tion technique based on the scatter of points in an amplitude-phase plane is used for most cases. A means of calculating smoothed mean curves is discussed. A Fourier transform method is presented for closely spaced data points, with prewhitening included for accurate secondary period and amplitude determinations.

Three test problems …

Theoretical Study Of Impurity-Induced First-Order Raman Spectra For The Alkali Halides, Arnold Karo, John R. Hardy

John R. Hardy Papers

A deformation-dipole model with first- and second-neighbor central short-range forces is used as a basis for calculating all symmetry-adapted combinations of eigenvectors (SACEV) necessary for the study of defect vibrations in alkali-halide crystals. As an example of the full set of spectral weight functions, which are tabulated separately, sample results are given for the predicted defect-activated E, Raman spectra for KC1, KI, RbCl, and KBr, assuming no force-constant changes and that the defect is located at a positive-ion site. The results show qualitative agreement with the earlier findings of Harley, Page, and Walker, even though the deformation-dipole model is not …

Theoretical Study Of Impurity-Induced First-Order Raman Spectra For The Alkali Halides, Arnold Karo, John Hardy

John R. Hardy Papers

A deformation-dipole model with first- and second-neighbor central short-range forces is used as a basis for calculating all symmetry-adapted combinations of eigenvectors (SACEV) necessary for the study of defect vibrations in alkali-halide crystals. As an example of the full set of spectral weight functions, which are tabulated separately, sample results are given for the predicted defect-activated E, Raman spectra for KCl, KI, RbCl, and KBr, assuming no force-constant changes and that the defect is located at a positive-ion site. The results show qualitative agreement with the earlier findings of Harley, Page, and Walker, even though the deformation-dipole model is not …

Some Comments On Correlation-Function Formulas For Polymer Intrinsic Viscosity, Walter H. Stockmayer, Gerald Wilemski, Hiromi Yamakawa, Genzo Tanaka

Physics Faculty Research & Creative Works

No abstract provided.

Energy And Angular Distribution Of Electrons Ejected From Helium By Fast Protons And Electrons: Theory And Experiment, Steven Trent Manson, Larry H. Toburen, Don H. Madison, Nikolaus Stolterfoht

Physics Faculty Research & Creative Works

A comprehensive study of the angular and energy distributions of electrons ejected in collisions of fast electrons and protons with He is presented. New experimental results for 300-keV, 1-MeV, and 5-MeV proton impact are reported along with theoretical results for 2-keV electron impact and 100-keV, 300-keV, 1-MeV, and 5-MeV proton impact. The theoretical results, based upon Born approximation with Hartree-Slater initial discrete and final continuum wave functions, show excellent agreement with experimental electron-impact results. Serious discrepancies are found between theory and experiment in the angular distribution of ejected electrons for forward angles for 100- and 300-keV proton impact; the discrepancies …

The Dynamics Of An Hcp Crystal With A Substitutional Defect, Pramod C. Karulkar

Dissertations and Theses

We examine the problem of the dynamics of a hexagonal close packed crystal with a single substitutional impurity. The effects of the mass and the force constant changes due to the introduction of the impurity atom are taken into account assuming nearest neighbor interactions under the harmonic approximation. Using Green’s function and group theoretical methods, the equations of motion for the perturbed normal modes are obtained in an exact form. The calculations are performed by allowing for very general force constant changes which can have noncentral as well as central contributions. Further, by assuming central forces, we simplify the equations …

Path Integrals With Arbitrary Generators And The Eigenfunction Problem, William B. Campbell, Paul Finkler, C. E. Jones, M. N. Misheloff

Paul Finkler Papers

We generalize the path integral formalism of quantum mechanics to include the use of arbitrary infinitesimal generators, thus providing explicit expressions for solutions of a wide class of differential equations. In particular, we develop a method of calculating the eigenfunctions of a large class of operators.