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Two-Step Photoionization Of Potassium Atoms, Kaare J. Nygaard, Robert J. Corbin, James A. Jones Jan 1978

Two-Step Photoionization Of Potassium Atoms, Kaare J. Nygaard, Robert J. Corbin, James A. Jones

Physics Faculty Research & Creative Works

The cross section for photoionization of potassium atoms in the 4P2 states has been measured in a triple-crossed-beam experiment. © 1978 The American Physical Society.

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Time Resolved Fluorescence Of The A ²∑+ State Of Gef, R. (Richard) A. Anderson, L. Hanko, S. J. Davis Jan 1978

Time Resolved Fluorescence Of The A ²∑+ State Of Gef, R. (Richard) A. Anderson, L. Hanko, S. J. Davis

Physics Faculty Research & Creative Works

The radiative lifetime and quenching rates for the A 2∑ + state of GeF have been measured in the flame of GeH 4+F2 by pulsed laser induced fluorescence. In addition, the radiative lifetime of the ν′=0 level of the A 2∑ + state of SiF has been measured in the flame of SiH 4+F2. Quenching rates for He, N2, and SF 6 on GeF A 2∑ and He on SiF A 2∑ have also been determined. The average zero pressure lifetime of ν′=0, 1, and 2 levels of A 2∑ GeF is 990±100 nsec. The zero-pressure lifetime of the A …

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A Xenon Ion Pumped Blue Dye Laser, D. W. Fahey, Laird D. Schearer Jan 1978

A Xenon Ion Pumped Blue Dye Laser, D. W. Fahey, Laird D. Schearer

Physics Faculty Research & Creative Works

A pulsed xenon ion laser with an output power of 5 kW at 364.5 nm has been used as a pump source for several blue dyes. Broadband conversion efficiencies exceed 20 percent. The use of a birefringent filter provides tunable output in the blue region of the spectrum with a bandwidth of 0.08 nm and a pulse width of 120 ns. © 1978 IEEE

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Note On The Constant Coupling Approximation, M. Jursich, Harry A. Brown Jan 1978

Note On The Constant Coupling Approximation, M. Jursich, Harry A. Brown

Physics Faculty Research & Creative Works

No abstract provided.

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The Coma/A1367 Supercluster And Its Environs, Stephen A. Gregory, Laird A. Thompson Jan 1978

The Coma/A1367 Supercluster And Its Environs, Stephen A. Gregory, Laird A. Thompson

Department of Physics and Astronomy: Faculty Publications

The three-dimensional galaxy distribution in the region of space surrounding the two rich clusters Coma and A1367 is analyzed by using a nearly complete redshift sample of 238 galaxies with mp < 15.0 in a 260 degree2 region of the sky; 44 of these redshifts are reported here for the first time. We find that the two clusters are enveloped in a common supercluster which also contains four groups and a population of isolated galaxies. The least dense portions of the Coma/A1367 supercluster have a density which is approximately 6 times that of the Local Supercluster in the regions of our own Galaxy. In …

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Studies Of The Temporary Anion States Of Unsaturated Hydrocarbons By Electron Transmission Spectroscopy, Kenneth D. Jordan, Paul Burrow Jan 1978

Studies Of The Temporary Anion States Of Unsaturated Hydrocarbons By Electron Transmission Spectroscopy, Kenneth D. Jordan, Paul Burrow

Paul Burrow Publications

The concept of occupied and unoccupied orbitals has provided a useful means for visualizing many of the most important properties of molecular systems. Yet, there is a curious imbalance in our experimental knowledge of the energies of occupied and unoccupied orbitals. Whereas photoelectron spectroscopy has provided a wealth of data on positive ion states and has established that they can be associated, within the context of Koopmans’ theorem, with the occupied orbitals of the neutral molecule, the corresponding information for the negative ion states, associated with the normally unoccupied orbitals, is sparse. In part this reflects the experimental difficulties connected …

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Precipitation Phenomena In Antimony-Implanted Aluminium, Richard Allen Kant Dec 1977

Precipitation Phenomena In Antimony-Implanted Aluminium, Richard Allen Kant

Physics & Astronomy ETDs

An experimental and theoretical study of the influence of temperature flux, and fluence on the formation and evolution of compounds formed by ion implantation has been conducted. Transmission electron microscopy was used to determine the size distribution of AJSb precipitates resulting from implanting single crystal A1 with Sb. In addition, the role of ion damage was investigated using both Ar and Al bombardment. These experiments show that for samples which initially contain no Sb, the number density of pre• cipitates decreases with increasing fluence and temperature, and with decreasing flux.

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Impurity Photomagnetoelectric Effect: Application To Semi-Insulating Gaas, David C. Look Dec 1977

Impurity Photomagnetoelectric Effect: Application To Semi-Insulating Gaas, David C. Look

Physics Faculty Publications

The theories of the photomagnetoelectric (PME) and photoconductivity (PC) effects in semiconductors are extended to include unequal excitation rates of holes and electrons, as might be expected from impurity photo-excitation. The results are applied to two semi-insulating Cr-doped GaAs crystals, which exhibit mixed conductivity. It is seen that the PC and PME effects give complementary information on the holes and electrons. In the impurity excitation region the PME current responds strongly to changes in the absorption coefficient, and provides a convenient way to study this quantity.

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The Electrical Characterization Of Semi‐Insulating Gaas: A Correlation With Mass‐Spectrographic Analysis, David C. Look Dec 1977

The Electrical Characterization Of Semi‐Insulating Gaas: A Correlation With Mass‐Spectrographic Analysis, David C. Look

Physics Faculty Publications

The room‐temperature electrical properties of 28 semi‐insulating GaAs crystals have been determined by using a mixed‐conductivity analysis. It is shown that for most of these samples, such an analysis gives good accuracy for the electron mobility μn and electron concentration n, but poorer accuracy for the hole mobility μp, hole concentration p, and intrinsic concentration ni. The intrinsic concentration is determined at 296 °K to be ni ≈ (1.7±0.4) ×106 cm−3, which compares favorably with the theoretical value deduced from the band gap and the effective masses. From a …

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Intense Flowing Hollow Cathode Lamp, F. H.K. Rambow, Laird D. Schearer Dec 1977

Intense Flowing Hollow Cathode Lamp, F. H.K. Rambow, Laird D. Schearer

Physics Faculty Research & Creative Works

An inexpensive, simple, and versatile hollow cathode lamp has been developed which produces intense ion resonance radiation of about 1 mW into 4π/25 sr. The lamp employs flowing helium gas to sustain the discharge. The construction permits a variety of cathode seed materials to be easily interchanged. The same lamp has been used as a source of ion resonance radiation for Ca, Ba, Zn, Mg, Sr, Yb, and Eu.

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Measurement Of The H- Photodetachment Cross Section In The Continuum Region From 1.5 To 10.5 Ev, Mohammad Hassan Sharifian-Attar Nov 1977

Measurement Of The H- Photodetachment Cross Section In The Continuum Region From 1.5 To 10.5 Ev, Mohammad Hassan Sharifian-Attar

Physics & Astronomy ETDs

We have measured the H photodetachment cross section in the photon energy range from 1.5 to 10.5 eV, using a colliding beam method. The H beam with an energy of 800 MeV, at Los Alamos Linear Accelerator, was intersected by a nitrogen laser beam with a photon energy of 3 .678 eV in the lab frame. We changed the energy of the pho"ton in the H rest frame, through the Doppler effect, by varying the angle between the laser and the H beams. The magnitude of the Doppler shift was enough to cover the entire range from 1.5 to 10.5 …

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Neutron-Proton Elastic Scattering At 790 Mev, Roger Daniel Carlini Nov 1977

Neutron-Proton Elastic Scattering At 790 Mev, Roger Daniel Carlini

Physics & Astronomy ETDs

The forward n-p differential cross-section is measured at 790 Mev from 9.5 to 60. degrees in the center of mass. The systematic errors are less than 4.0%. The differential cross-section is parameterized by the function dσ/dΩ = A ebt, where t is the momentum transfer between the incoming and outgoing neutrons in (GeV/C)2, and A and b are constants having the values A= 9.757±.069, b= 5.052±.045. With 36 data points the x2 is 55. The magnitude of the ratio of the real to imaginary part of the forward scattering amplitude is found to be .3501±.14.

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Alignment Of Helium Excited By Thin Carbon Foils, R. D. Hight, R. M. Schectman, H. G. Berry, G. Gabrielse, Timothy J. Gay Nov 1977

Alignment Of Helium Excited By Thin Carbon Foils, R. D. Hight, R. M. Schectman, H. G. Berry, G. Gabrielse, Timothy J. Gay

Timothy J. Gay Publications

We have measured the linear polarization of the 5016-Å, 2s 1S-3p 1P transition of Hei excited by a thin carbon foil perpendicular to the incident He+ beam at ion energies 50-500 keV. We find that the alignment of the 3p 1P term depends upon the beam current density within the range (2- 150 μA cm-2) measured. Oscillations in the dependence of both M / I (the linear polarization fraction) upon energy and the current density variation of M / I with energy are observed. We discuss possible origins of these variations.

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Alignment Of Helium Excited By Thin Carbon Foils, R. D. Hight, R. M. Schectman, H. G. Berry, G. Gabrielse, Timothy J. Gay Nov 1977

Alignment Of Helium Excited By Thin Carbon Foils, R. D. Hight, R. M. Schectman, H. G. Berry, G. Gabrielse, Timothy J. Gay

Timothy J. Gay Publications

We have measured the linear polarization of the 5016-Å, 2s 1S-3p 1P transition of Hei excited by a thin carbon foil perpendicular to the incident He+ beam at ion energies 50-500 keV. We find that the alignment of the 3p 1P term depends upon the beam current density within the range (2- 150 μA cm-2) measured. Oscillations in the dependence of both M / I (the linear polarization fraction) upon energy and the current density variation of M / I with energy are observed. We discuss possible origins of these …

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Convection In Pulsating Stars, Michael John Robert Costello Oct 1977

Convection In Pulsating Stars, Michael John Robert Costello

Physics & Astronomy ETDs

Stellar models using mixing length convection in a linear calculation show a red edge to the instability strip. The models are of a 6 solar mass, 1 x 10 ergs/sec luminos­ity, King 4A composition, cepheid variable star, for various values of effective temperature, Te, and mixing length parameter, a. Results are obtained with an assumed instantaneous adjustment of the convective flux to changes in the local stellar conditions. Calculations of the convective time de­lay show it to be small compared to the period, under the assumption that the convective time delay is due solely to the inertia of convective bubbles. …

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Ferromagneticlike Resonance Behavior In Superfluid 3he-B, Richard A. Webb Oct 1977

Ferromagneticlike Resonance Behavior In Superfluid 3he-B, Richard A. Webb

Faculty Publications

Nonlinear cw NMR behavior, similar to that observed on ferromagnets at high rf powers, has been observed in superfluid 3He-B using a superconducting quantum interference device (SQUID) magnetometer in fields of 31, 102, 180, and 308 Oe and at a pressure of 21 bar. It is observed that beyond some threshold value of the transverse H1 field the z component of magnetization anomalously decreases and is followed by a rapid increase back to the normal resonance curve as the frequency of the H1 field is swept through resonance.

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The Water Monomer On The Basal Plane Of Ice Iₕ: An Effective Pair, Central Force Potential Model Of The Static Interaction, Jerry Kiefer, Barbara N. Hale Oct 1977

The Water Monomer On The Basal Plane Of Ice Iₕ: An Effective Pair, Central Force Potential Model Of The Static Interaction, Jerry Kiefer, Barbara N. Hale

Physics Faculty Research & Creative Works

The H2O-H2O intermolecular central force potential of Lemberg and Stillinger is used to obtain optimal binding energy surfaces, vibrational frequencies, and bonding configurations of an adsorbed water monomer on a model basal plane of ice Ih. The monomer interacts (pairwise) with 50 molecules arranged in two layers of the unrelaxed bulk ice lattice. The results of calculations for three model surface sites of differing proton arrangement indicate the existence of diffusion barriers of the order of 2.5 kcal/mole and optimal monomer bonding sites at about 9 kcal/mole with nonepitaxial characteristics. Perspective computer-drawn plots of …

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Christian Commitment And Scientific Theories, Wytze Brouwer Sep 1977

Christian Commitment And Scientific Theories, Wytze Brouwer

Pro Rege

No abstract provided.

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Single-Element Rotating-Polarizer Ellipsometer For Film-Substrate Systems, A.-R. M. Zaghloul, R. M.A. Azzam Sep 1977

Single-Element Rotating-Polarizer Ellipsometer For Film-Substrate Systems, A.-R. M. Zaghloul, R. M.A. Azzam

Electrical Engineering Faculty Publications

A novel and very simple ellipsometer for the characterization of film-substrate systems that employs one rotating optical element (a polarizer) is proposed. The ellipsometer is based on detecting the angles of incidence at which a film-substrate system has equal amplitude attenuations for light polarized parallel (p) and perpendicular (s) to the plane of incidence. At a certain wavelength, the film thickness of the filmsubstrate system has to lie within permissible-thickness bands (PTB) for the technique to apply.

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The Use Of Nuclear Reactions And Sims For Quantitative Depth Profiling Of Hydrogen In Amorphous Silicon, David D. Allred, G. J. Clark, C. W. White, B. R. Appleton, C. W. Magee, D. E. Carlson Aug 1977

The Use Of Nuclear Reactions And Sims For Quantitative Depth Profiling Of Hydrogen In Amorphous Silicon, David D. Allred, G. J. Clark, C. W. White, B. R. Appleton, C. W. Magee, D. E. Carlson

Faculty Publications

Depth profiles for hydrogen in amorphous silicon have been determined by the use of resonant nuclear reactions [1H(15N,αγ)12C and 1H(19F,αγ)16O] and by secondary ion mass spectroscopy (SIMS). Independent calibration procedures were used for the two techniques. Measurements were made on the same amorphous silicon film to provide a direct comparison of the two hydrogen analysis techniques. The hydrogen concentration in the bulk of the film was determined to be about 9 at % H. The SIMS results agree with the resonant nuclear reaction results to within 10%, which demonstrates that quantitative hydrogen depth profiles can be obtained by SIMS analysis …

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19th Annual Conference On Analytical Chemistry Aug 1977

19th Annual Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Program and abstracts from the 19th annual meeting of the Conference on Analytical Chemistry, co-sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy and the Rocky Mountain Chromatography Discussion Group. Held in Denver, Colorado, August 1-3, 1977.

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Analysis Of Chert By Particle Induced X-Ray Emission, Jeanette E. Gibeson Aug 1977

Analysis Of Chert By Particle Induced X-Ray Emission, Jeanette E. Gibeson

Masters Theses

No abstract provided.

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Method Of Variational Secular Equation For The Ground State Of Helium Atom, Mih-Seh Kong Aug 1977

Method Of Variational Secular Equation For The Ground State Of Helium Atom, Mih-Seh Kong

Masters Theses

No abstract provided.

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Erratum: Excitation Of The N=2 State Of Atomic Hydrogen By Electron Impact In The Distorted-Wave Approximation (Physical Review A (1977) 16, 2), Ralph V. Calhoun, Don H. Madison, W. Neil Shelton Aug 1977

Erratum: Excitation Of The N=2 State Of Atomic Hydrogen By Electron Impact In The Distorted-Wave Approximation (Physical Review A (1977) 16, 2), Ralph V. Calhoun, Don H. Madison, W. Neil Shelton

Physics Faculty Research & Creative Works

No abstract provided.

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Heights Of Formation For Certain Solar Spectral Lines, Erik J. Schwendeman Jul 1977

Heights Of Formation For Certain Solar Spectral Lines, Erik J. Schwendeman

Physics & Astronomy ETDs

Heights of formation are calculated for several of the solar spectral lines studied by the National Aeronautics and Space Administration - Goddard Space Flight Center (NASA-GSFC) New Mexico Solar Station at Sacramento Peak Observatory. These lines are Ca II H, K, 8498 Å and 8542 Å, MgI b1, NaI D1 and D2 and Sil 4103 Å. I calculate the heights of formation for each of these lines along with upper and lower confidence limits representing the height region where 90% of the total intensity of the line is formed in the solar photosphere and chromosphere. The …

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A Covariant Approach To Wave Equations In General Relativity, Alan L. Dudley Jul 1977

A Covariant Approach To Wave Equations In General Relativity, Alan L. Dudley

Physics & Astronomy ETDs

A formalism for the manipulation of tensors in both real and complex spacetimes is introduced, which utilizes the irreducible representations of the Lorentz group to substantially simplify certain general relativistic calculations. The notation is completely covariant and is most effective for massless field calculations. Results emerge which eliminate the majority of the algebraic burden of the traditional Newman­Penrose formalism and, simultaneously, allow the reader to understand both the physical and geometrical meanings of each step of the derivations. The technique developed is well suited for perturbation analyses. Consequently, the perturbed wave equations for massless fields are examined. The notation has …

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³⁴Cl Via The ³²S(³He,P) Reaction, Oleksa-Myron Bilaniuk, D. J. Crozier, H. T. Fortune, R. Middleton Jul 1977

³⁴Cl Via The ³²S(³He,P) Reaction, Oleksa-Myron Bilaniuk, D. J. Crozier, H. T. Fortune, R. Middleton

Physics & Astronomy Faculty Works

The structure of ³⁴Cl has been investigated with the reaction ³²S(³He,p). Angular distributions were obtained for 29 levels below 5 MeV excitation. Extracted L values, combined with previous information, allow J^π assignments of 3⁺ for states at 2181 and 2611 keV, negative parity for the J=4 state at 3600 keV, 2⁻ for the level at 4514 keV, and 3⁻ (2⁻) for states at 4416 and 4461 keV. Two new states are observed at excitation energies of 4693 and 4825 keV. [NUCLEAR REACTIONS ³²S(³He,p),E(³He)=18 MeV; measured σ(Ep,θ); gas H2S target. ³⁴Cl deduced levels, L, J, π.]

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X-Ray Investigation Of The Critical Exponent Η In Argon, Harold D. Bale, J. S. Lin, Duane A. Dolejsi, James L. Casteel, Oran Allan Pringle, Paul W. Schmidt Jul 1977

X-Ray Investigation Of The Critical Exponent Η In Argon, Harold D. Bale, J. S. Lin, Duane A. Dolejsi, James L. Casteel, Oran Allan Pringle, Paul W. Schmidt

Physics Faculty Research & Creative Works

Measurements were made of the small-angle x-ray scattering intensity from argon near the critical point. After the scattering curves are corrected for all known effects except those resulting from irrelevant variables, a value of the critical exponent η=0.09±0.02 is obtained, while if a correction for the estimated effect of irrelevant variables is also made, η=0.03±0.03. The scattering data for argon therefore show that if irrelevant variables can be neglected, the critical exponent η for argon is in good agreement with the value obtained by Warkulwiz, Mozer, and Green from small-angle neutron scattering data for neon. These values of η, however, …

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Static Temperature Measurements In Supersonic Flow Using Lasar Raman Spectroscopy, Paul A. Nystrom Jul 1977

Static Temperature Measurements In Supersonic Flow Using Lasar Raman Spectroscopy, Paul A. Nystrom

Mechanical & Aerospace Engineering Theses & Dissertations

Laser Raman spectroscopy is a nonintrusive technique which can generate mean static temperature (MST) data within flow fields. By ratioing two simultaneously gathered portions of the Raman scattered spectrum, absolute intensity measurements were not needed. This method was applied to a supersonic cold air jet, where the NST ranged from 160'K to 300'K. Accurate measurements were not realized due to the presence of flow contaminates, especially water vapor.

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Behavior Of Partial Cross Sections And Branching Ratios In The Neighborhood Of A Resonance, Anthony F. Starace Jul 1977

Behavior Of Partial Cross Sections And Branching Ratios In The Neighborhood Of A Resonance, Anthony F. Starace

Anthony F. Starace Publications

Starting from the treatment of Fano for the behavior of the total cross section in a photoionization (or electron-ion scattering) experiment in the vicinity of a resonance, we present a theoretical formula for the behavior of an individual final-state channel in the neighborhood of a resonance. This result is then used to derive another theoretical formula for the behavior of the ratio of two partial cross sections (i.e., the branching ratio) in the vicinity of a resonance. This branching-ratio formula depends on the profile parameters q, Γ, and ρ2 for the resonance, on the branching ratio outside the resonance, …

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