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Physics

1967

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Full-Text Articles in Physical Sciences and Mathematics

Strong-Coupled Piezoelectric Polaron, Wayne E. Tefft Dec 1967

Strong-Coupled Piezoelectric Polaron, Wayne E. Tefft

Physics Faculty Research & Creative Works

A semiclassical, variational calculation for the strong-coupled piezoelectric polaron gives the following results for the ground-state energy and polaron radius, respectively: U0=-0.47(m*/m) (κ2/ε)2eV, and R=3.5(ε/κ2) (m/m*)â ã where m* is the band effective mass, κ is the electromechanical coupling constant, and ε is the strain-free dielectric constant. The theory is expected to be valid when |U0| is larger than thermal energies and R is considerably larger than unit-cell dimensions. A calculation of the polaron effective mass, having a more limited region of validity, gives mp~m*[1+2|U0|/m*vs2], where vs is the velocity of sound. …

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Hyperfine-Structure Separations, Nuclear Magnetic Moments, And Hyperfine-Structure Anomalies Of Gold-198 And Gold-199, Paul A. Vanden Bout, Vernon J. Ehlers, William A. Nierenberg, Howard A. Shugart Dec 1967

Hyperfine-Structure Separations, Nuclear Magnetic Moments, And Hyperfine-Structure Anomalies Of Gold-198 And Gold-199, Paul A. Vanden Bout, Vernon J. Ehlers, William A. Nierenberg, Howard A. Shugart

University Faculty Publications and Creative Works

We have measured the hyperfine-structure separations and nuclear magnetic moments of (2.70-day) Au198 and (3.15-day) Au199 in the S122 state, using the atomic-beam magnetic-resonance method. We also measured the ratios of the electronic g factor of gold to those of potassium and cesium. The results are, for Au198 (I=2), Δν=21450.7167(4) MHz, μI(uncorr)=+0.5842(4) nm; and for Au199 (I=32), Δν=10962.7227(3) MHz, μI(uncorr)=+0.2673(7) nm. The results for the g-factor ratios are: gJ(Au)gJ(K)=1.000504(2) and gJ(Au)gJ(Cs)=1.000381(2). These values yield the following hyperfine-structure anomalies: Δ198197=8.53(8)% and Δ199197=3.7(2)%. Second-order corrections to the hyperfine structure are shown to be negligible. The nuclear results are interpreted in terms of …

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Survival Probability In Dissociative Attachment, Joseph C.Y. Chen, Jerry Peacher Nov 1967

Survival Probability In Dissociative Attachment, Joseph C.Y. Chen, Jerry Peacher

Physics Faculty Research & Creative Works

The survival probability in dissociative attachment is investigated with special attention to the (e, H2 ) system. It is shown that the simple expression for the dissociative-attachment cross section, as given by the product of a capture cross section and a survival probability, is equivalent to the s -wave approximation for the g → g dissociative attachment. This expression, however, does not constitute an approximation for the g → u dissociative attachment, since the parity of the initial rotational states of H2 is always opposite to that of the relative angular momentum states of H and H- …

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Very High Pressure Effects Upon The Epr Spectrum Of Ruby, H. Mark Nelson, D. B. Larson, J. H. Gardner Sep 1967

Very High Pressure Effects Upon The Epr Spectrum Of Ruby, H. Mark Nelson, D. B. Larson, J. H. Gardner

Faculty Publications

The variation in the electron paramagnetic resonance (EPR) spectrum of ruby as a function of pressure has been observed to beyond 70 kbar for a magnetic field orientation parallel to the crystalline c axis. The data can be interpreted in terms of the usual spin Hamiltonian, where the spectroscopic splitting factor g|| has the same value as at ambient pressures, but where the zero-field splitting deltaincreases in a linear fashion from 0.38 to 0.43 cm. The experimental apparatus has been described previously, although important improvements in the pressure seal and in the pressure calibration have been made and are described …

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Mössbauer Study Of Ferrimagnetic Ordering In Nickel Ferrite And Chromium-Substituted Nickel Ferrite, J. Chappert, Richard B. Frankel Sep 1967

Mössbauer Study Of Ferrimagnetic Ordering In Nickel Ferrite And Chromium-Substituted Nickel Ferrite, J. Chappert, Richard B. Frankel

Physics

Mössbauer-effect measurements in external magnetic fields show that the magnetic structure of ferrimagnetic NiFe2O4 is the collinear Néel type. NiFe0.3Cr1.7O4 is shown to have a triangular structure with θA=20±10° and θB=50±4°.

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High-Field Magnetoresistance Of Ordered Beta Brass , David J. Sellmyer, J. Ahn, J.-P. Jan Sep 1967

High-Field Magnetoresistance Of Ordered Beta Brass , David J. Sellmyer, J. Ahn, J.-P. Jan

David Sellmyer Publications

The magnetoresistance of several single-crystal specimens of ordered β-brass has been investigated in fields up to 150 kG. The purity of the samples is sufficiently high (ρ295/ρ4.2≃400) that the high-field condition is satisfied. The results indicate that ordered β-brass is an uncompensated metal and that its Fermi surface is multiply connected. Strong open orbits were observed when the field was in {110} or {100} planes, and this behavior is compatible with the Fermi-surface model predicted by augmented-plane-wave and Green's-function energy-band calculations. Evidence for the existence of higher-order open orbits and two-dimensional regions of open orbits is …

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Room-Temperature Second-Order Raman Spectra Of Csc1, Csbr, And Csi, A. M. Karo, John R. Hardy Aug 1967

Room-Temperature Second-Order Raman Spectra Of Csc1, Csbr, And Csi, A. M. Karo, John R. Hardy

John R. Hardy Papers

The room-temperature Raman spectra of CsC1, CsBr, and CsI have been computed from a simple, combined density-of-states approximation. Calculations have been made for four different model potential functions and compared with experiment in the cases of CsBr and CsI. In this way it is found that one of the variations, called the DD(-) model, is the most satisfactory. The agreement with the observed spectra is surprisingly close when one considers that no allowance has been made for variations in the elements of the Raman polarizability tensor.

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9th Annual Meeting Rocky Mountain Spectroscopy Conference Aug 1967

9th Annual Meeting Rocky Mountain Spectroscopy Conference

Rocky Mountain Conference on Magnetic Resonance

Program and abstracts from the 9th 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 7-8, 1967.

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Measurement Of Ultrasonic Absorption In Liquids By A Thermal Method, Ronald J. Tanis Aug 1967

Measurement Of Ultrasonic Absorption In Liquids By A Thermal Method, Ronald J. Tanis

Masters Theses

No abstract provided.

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Conductive Sphere On A Charged Conductive Plane, Birney Robert Fish Aug 1967

Conductive Sphere On A Charged Conductive Plane, Birney Robert Fish

Masters Theses

Statement of the Problem: If a conductive sphere is placed in contact with a semi-infinite, conductive plane, the configuration constitutes a three-dimensional equipotential surface. Assuming an isolated plane to be electrically charged to a known surface charge density (σ°) originally, it is desired to determine the effect produced by placing a sphere on the plane. Specifically, the purpose of this investigation is to determine the force exerted on the sphere normal to the plane, the total charge acquired by the sphere and the perturbation in the electrical field due to its presence on the plane.

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Noise In Cadmium Sulfide & Cadmium Selenide Photoconductive Cells, Edward Foster Aug 1967

Noise In Cadmium Sulfide & Cadmium Selenide Photoconductive Cells, Edward Foster

Masters Theses & Specialist Projects

The primary object of this investigation is to design a system, including equipment and procedures, that can be used to evaluate the noise characteristics of photoconductive cells. The data once collected must be in a comprehensive and useful form. The secondary object is to use this system to evaluate a large number of cells of various types and to compare their noise profiles in a manner such that definite conclusions can be drawn concerning the absolute noise levels and profiles generated by the various cell types and the relations that may exist between the cells' noise output and the way …

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An Investigation Of The Refractive Index Of Selected Liquids In The Ultraviolet, Robert Bruce Eaton Aug 1967

An Investigation Of The Refractive Index Of Selected Liquids In The Ultraviolet, Robert Bruce Eaton

Masters Theses

No abstract provided.

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Fe1+ And Fe2+ Hyperfine Fields In Mgo And Cao, J. Chappert, Richard B. Frankel, N. A. Blum Jul 1967

Fe1+ And Fe2+ Hyperfine Fields In Mgo And Cao, J. Chappert, Richard B. Frankel, N. A. Blum

Physics

Hyperfine interactions have been measured for Fe1+ and Fe2+ in MgO and CaO. The core polarization fields per spin moment are −127 kOeμB for both Fe1+ and Fe2+.

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Evaluation Of The Dispersion Relations Of Photoproduction, Paul Finkler Jul 1967

Evaluation Of The Dispersion Relations Of Photoproduction, Paul Finkler

Paul Finkler Papers

A modification of the Omnes method is used to solve the singular integral equations for the 3-3 partialwave amplitudes of photoproduction. The effects of multipion production are assumed to be negligible. The method requires a knowledge of the phase at all energies. Consequently, it is necessary to treat the corresponding pion-nucleon scattering problem to determine the eBect of the high-energy behavior of the phase on the solution for the scattering amplitude at low energies. The sharply resonant nature of the problen suggests an approximation in the form of solution, rather than in the Born terms, which leads to relatively simple …

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Anion Contributions To The Electrical Conductivity Of Alkali Chlorides, Robert Fuller, M.H. Reilly Jul 1967

Anion Contributions To The Electrical Conductivity Of Alkali Chlorides, Robert Fuller, M.H. Reilly

Robert G. Fuller Publications

The measured electrical conductivity of pure RbCl is separated into the usual anion and cation contributions with activation energies of 2.55 and 1.58 eV, respectively. By comparison with corresponding results for KC1 and NaCl it is found that the alkali-chloride anion and cation activation energies differ most for nearly equal anion and cation radii. We conclude from this anomalous trend that an extension of conventional theory is required.

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F Band In X- And Electron-Irradiated Caf2, David A. Patterson, Robert Fuller Jun 1967

F Band In X- And Electron-Irradiated Caf2, David A. Patterson, Robert Fuller

Robert G. Fuller Publications

This Letter reports an investigation using pulsed electron irradiation to determine if the low efficiency of F-band coloration in calcium fluoride is caused by the instability of the F center. No transient F centers were seen in times as short as 2 x 10-7 sec. It is concluded that the inherent efficiency of F-band coloration in CaF2 is small compared with similar processes in alkali halides and a possible reason for this is discussed.

Calcium fluoride has been extensively studied and is found to be more difficult to color than alkali halides and to have absorption …

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Integral Series Solution Of The Schrödinger Equation For The Helium Atom, W. Byers Brown, Ronald White Jun 1967

Integral Series Solution Of The Schrödinger Equation For The Helium Atom, W. Byers Brown, Ronald White

Center for Advanced Mineral and Metallurgical Processing (CAMP)

No abstract provided.

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Mössbauer Evidence For A Spin-Compensated State In Dilute Fe-Cu Alloys, Richard B. Frankel, N. A. Blum, Brian B. Schwartz, Duk Joo Kim Jun 1967

Mössbauer Evidence For A Spin-Compensated State In Dilute Fe-Cu Alloys, Richard B. Frankel, N. A. Blum, Brian B. Schwartz, Duk Joo Kim

Physics

No abstract provided.

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Analytic Power-Series Solution Of The Schrödinger Equation For The Helium Atom, W. Byers Brown, Ronald White Jun 1967

Analytic Power-Series Solution Of The Schrödinger Equation For The Helium Atom, W. Byers Brown, Ronald White

Center for Advanced Mineral and Metallurgical Processing (CAMP)

No abstract provided.

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Inelastic Collisions Of The Second Kind Between Electrons And Excited Mercury Atoms, Paul Burrow Jun 1967

Inelastic Collisions Of The Second Kind Between Electrons And Excited Mercury Atoms, Paul Burrow

Paul Burrow Publications

The relative cross section for inelastic collisions of the second kind between electrons and mercury atoms in the excited 3P1 state was measured as a function of electron energy. Excited atoms were produced by absorption of the 2537 Å resonance line from a mercury arc. A low-energy beam of electrons was produced using the retarding potential difference method. Scattered electrons which gained kinetic energy were detected by passing them through a potential barrier which reflected unscattered electrons. The data are in good agreement with the cross section computed by applying detailed balancing to the known cross section for …

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Rocket Probe Measurement Of Electron Energy Spectra In The Earth's Radiation Belts, Donald Stuart Robb Jun 1967

Rocket Probe Measurement Of Electron Energy Spectra In The Earth's Radiation Belts, Donald Stuart Robb

Physics & Astronomy ETDs

No abstract provided.

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Nuclear Quadrupole Relaxation., Derwin F. Brown Jun 1967

Nuclear Quadrupole Relaxation., Derwin F. Brown

Physics & Astronomy ETDs

A nucleus with an asymmetric charge distribution (an asymmetric arrangement of protons) exhibits a quadrupole moment which interacts with the gradient of the electric field of the surrounding electrons. The interaction energy is a function of the angle between the nuclear spin axis and the axis of the surrounding electric field. The nucleus processes about the electric field axis in quantized energy states. These quantized energy states correspond to a hyperfine splitting simi­lar to the hyperfine structure of the magnetic dipole-dipole interaction between the nucleus and the electrons. The application of an external electric field, oscillating at the processional frequency …

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An Introduction To The Fundamentals Of Radiation Transport Theory., William A. Proctor Jun 1967

An Introduction To The Fundamentals Of Radiation Transport Theory., William A. Proctor

Physics & Astronomy ETDs

I first became interested in radiation transport theory when, in August 1966, I was given primary responsibility for a large computer program which serves as a tool for solving high temperature, time dependent, radiation-hydrodynamics problems. Inquiries as to where to start learning about this subject invariably resulted in my being directed to the two books by Chandrasekhar (1957 and 1960) and the book by Kourganoff (1963). From the beginning of my study of these expositions, I found it rather curious that a theory which treated the radiation field as continuously distributed in space was formulated in a manner which appeared …

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Rapid Calculation Of Electron Scattering Factors, Jerry Peacher, John G. Wills Jun 1967

Rapid Calculation Of Electron Scattering Factors, Jerry Peacher, John G. Wills

Physics Faculty Research & Creative Works

The phase amplitude method is used to reduce the radial Schrödinger equation to two separate differential equations, one for the phase and one for the amplitude. These functions are both smooth as opposed to the rapidly oscillating solution of the radial Schrödinger equation for electron energies in the kilovolt range. The partial-wave phase shifts were obtained rapidly by integrating the differential equations for the phase and amplitude numerically. Hartree-Fock and Thomas-Fermi-Dirac fields were used in the calculation. Results for argon and uranium are given in order to compare with previous results. It was found that the WKBJ approximation to the …

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A Study Of Chromium-Doped High Lead Containing Silicate Glasses For Possible Laser Action, Mervet Maurice Saleh Jun 1967

A Study Of Chromium-Doped High Lead Containing Silicate Glasses For Possible Laser Action, Mervet Maurice Saleh

Archived Theses and Dissertations

No abstract provided.

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Environmental Effects On The Resistivity Of Palladium-Silver Alloy Films In High Vacuum, Frank Snyder Jun 1967

Environmental Effects On The Resistivity Of Palladium-Silver Alloy Films In High Vacuum, Frank Snyder

Masters Theses & Specialist Projects

The reported usage of the palladium-silver alloy films as resistors in the electronics industry has been in encapsulated form. By mounting the resistor inside vacuum electron devices, there is the possibility of eliminating the encapsulation. A literature search has revealed no reported efforts of experiments with unencapsulated resistors and certainly no reports of the palladium-silver alloy resistor in vacuum tubes or other high vacuum environments. Therefore, the research reported in this thesis will concentrate on the environmental effects on resistivity of palladium-silver alloy films in high vacuum.

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Analysis Of Particle Counting Rate Variations Observed On Satellite Oso-B2, Esther Y. Ma May 1967

Analysis Of Particle Counting Rate Variations Observed On Satellite Oso-B2, Esther Y. Ma

Physics & Astronomy ETDs

The ommidirectional cosmic ray fluxes at an altitude of 300 miles and within ± 34 degrees latitude were studied using two Cerenkov counters and a scintillation counter aboard the 0S0-82 Satellite. The fluxes were found to depend strongly on the geomagnetic field with the trapped particles in the South Atlantic Radiation Anomaly being directional in some locations.

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²⁰⁷Pb (N, N') ²⁰⁷Pbm And ²⁰⁸Pb (N, 2n) ²⁰⁷Pbm Cross Sections, Edward Raymond Shunk May 1967

²⁰⁷Pb (N, N') ²⁰⁷Pbm And ²⁰⁸Pb (N, 2n) ²⁰⁷Pbm Cross Sections, Edward Raymond Shunk

Physics & Astronomy ETDs

The cross sections for the production of the 207Pbm state from 207Pb(n, n') and 208Pb(n, 2n) have been measured from the threshold through 14 MeV by observing the 1 .064 MeV gamma ray in the decay of 207Pbm (T ½ = 0.818 ± 0.004 sec) with a 3 in. x 3 in. NaI (T1) detector. Separated lead isotopes were irradiated for 4 sec and pneumatically transported to the detector. A 400-channel analyzer a used a time analyzer to record counts from neutron monitor during the irradiation and from the detector after the irradiation. These …

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Surface-Wave Phenomena At Liquid-Air Interfaces, Robert H. Dungan May 1967

Surface-Wave Phenomena At Liquid-Air Interfaces, Robert H. Dungan

Physics & Astronomy ETDs

The purpose of this investigation was to continue the study of surface wave phenomena initiated by Woodward and Bryant. [l], [2] Woodward, using an experimental arrangement similar to that shown in Fig. 3, observed that the intensity of light measured above, but parallel to, the reflected beam was a very sharp function of the incident beam angle at the critical angle. They also observed that the light intensity above the reflected beam decreased exponentially as the detector was moved away from the reflected beam in the plane of incidence. They reported characteristic lengths for the exponential decay constant of 9.6 …

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Observation Of Centrifugal Stretching In Sm152, D. Yeboah-Amankwah, L. Grodzins, Richard B. Frankel May 1967

Observation Of Centrifugal Stretching In Sm152, D. Yeboah-Amankwah, L. Grodzins, Richard B. Frankel

Physics

An isomer shift has been observed in the Mössbauer study of the 121.8-keV (2+→0+) transition in Sm152. A value of (Δ〈R2〉/〈R2〉)2-0=(10±3)×10-4 is deduced, based on isotope shift data for Sm152 and Sm154. This value disagrees with present theoretical prediction. In particular, the influence of the β band in Sm152 can only account for about 20% of the observed stretching.

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