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Determination Of The Origin Of The 10.6-Pm Absorption In C02 Laser Window Materials, John R. Hardy, B. S. Agrawal

John R. Hardy Papers

Theoretical studies are presented which show that it should be possible to determine whether the absorption at 10.6 pm in alkali halides is due to impurities or whether it is intrinsic. These studies show that the temperature dependence of the measured absorption should be very different for intrinsic multiphonon absorption as compared with defect-activated absorption.

Projected Hartree Product Wavefunctions. Vi. Natural Orbital Ci Expansions In Nonsinglet Cases, R.D. Koller, Gordon A. Gallup

Gordon Gallup Publications

The NSO's and NO's have been determined for some wavefunctions for Li, Be¹⁺, B²⁺, C^{3+ 2}S, and Be ³S wavefunctions containing radial correlation. It is shown how the NO's may be utilized to form rapidly converging CI expansions in general. The role of the NSO's in this problem is discussed. ©1973 The American Institute of Physics

Observation Of A Second-Order Phase Transition And Its Associated P - T Phase Diagram In Liquid He3, Richard A. Webb, T. J. Greytak, R. T. Johnson, J. C. Wheatley

Faculty Publications

A specific-heat "discontinuity" is observed in liquid He³ from 241 lb/in.2 to the melting pressure in the temperature range 2-3 mK.

Distorted-Wave Approximation And Its Application To The Differential And Integrated Cross Sections For Electron-Impact Excitation Of The 2¹P State Of Helium, Don H. Madison, W. Neil Shelton

Physics Faculty Research & Creative Works

Theoretical results are given for the application of the distorted-wave approximation to electron-atom impact excitation for transitions from an L-S coupled initial state to an arbitrarily coupled final state. Expressions for the differential cross section and spin polarization of the emitted electrons are given for unpolarized electron beams incident upon unpolarized atoms. These results are applied to excitation of helium from its ground state to the 1s2p¹P₁ excited state for incident-electron energies between 26.5 and 300 eV. The results are compared with previous theoretical and experimental works. It is found that the distorted-wave calculation is superior to …

Spin Polarization And Differential Cross Section For Electron-Impact Excitation Of The 6s6p ¹P₁ State Of Mercury: Distorted-Wave Treatment, Don H. Madison, W. Neil Shelton

Physics Faculty Research & Creative Works

The results of the distorted-wave theory for electron-impact excitation of atoms are applied to the excitation of the 6s6p ¹P₁ state of mercury. The spin polarization and the differential cross section are given for unpolarized incident electron beams with energies between 25 and 180 eV. The distorted-wave results are compared with experimental data, and good agreement is found for both the spin polarization and differential cross section.

Radiative And Predissociative Lifetimes Of The A ²Σ+ State Of Oh, Richard Orlin Sutherland, Richard A. Anderson

Chemistry Faculty Research & Creative Works

Lifetime measurements have been made on the A 2Σ+ state of OH by the delayed coincidence technique in conjunction with an interrupted rf discharge through water vapor. Lifetimes are reported for rotational states up to K=29 and K=20 in the ν=0 and ν=1 vibrational levels, respectively, and on the unresolved levels of ν=2. A predissociation, previously predicted from relative intensity measurements, resulting from a curve crossing by the repulsive 4Σ− state, was observed for the rotational states above K=23 of ν=0, for those above K=14 of ν=1, and for all those of ν=2. These lifetime data are discussed qualitatively in …

Absolute Line Strengths By Analysis Of Lu-Fano Plots With Application To Excited State Transitions In Neon, Anthony F. Starace

Anthony F. Starace Publications

Using energy eigenfunctions obtained by semi-empirical analysis of the Lu-Fano plot of energy level positions and employing the Coulomb approximation of Bates and Damgaard, we calculate absolute line strengths for transitions between the neon two-channel Rydberg series 2p⁵(²P_3/2,1/2)ns J = 1 and 2p⁵ (²P_3/2,1/2)n′ p J = 0 for n, n' = 3,4. Each Rydberg series is analyzed separately to obtain a set of five parameters which completely define the energy eigenfunctions for all values of n and n'. Interactions between the ns J = 1 …

Brief Theory Of Coherent Processor, Richard C. Heyser

Unpublished Writings

The particular coherent data processor which is to be discussed relies heavily upon several basic concepts. These concepts represent a departure from conventional practice and hence the theoretical description must await their presentation in order to gain some continuity. We will accordingly present the underlying assumptions and signal physics prior to description of the processor itself.

Quasifree (P,Pα) Scattering On ⁶Li, ²⁴Mg, ²⁸Si, ⁴⁰Ca, ¹⁴⁰Ce, And ²³²Th At 156 Mev, D. Bachelier, M. Bernas, Oleksa-Myron Bilaniuk, J. L. Boyard, J. C. Jourdain, P. Radvanyi

Physics & Astronomy Faculty Works

Knockout of α particles by 156-MeV protons from ⁶Li, ²⁴Mg, ²⁸Si, ⁴⁰Ca, ¹⁴⁰Ce, and ²³²Th has been used to investigate the A dependence of α clustering in nuclei. Protons and α particles were detected in coincidence under conditions of quasifree scattering. Corresponding reaction cross sections were measured. Cross sections for ²⁴Mg and ⁴⁰Ca were found to be about 2 orders of magnitude lower than for ⁶Li. The cross section for ²⁸Si was found to be about 3 times lower than that for ²⁴Mg and ⁴⁰Ca. Upper limits of the integrated cross sections for ¹⁴⁰Ce and ²³²U are still compatible with …

Carbon Interstitial In The Diamond Lattice, C Weigel, David Peak, J W. Corbett, R P. Messmer, G D. Watkins

All Physics Faculty Publications

Linear-combination-of-atomic-orbitals-molecular-orbitals cluster calculations using the extended Hückel theory are carried out for the interstitial carbon in the diamond lattice. The results suggest that the interstitial configuration is not the tetrahedral or hexagonal site, as has been previously assumed, but is instead an "interstitialcy" configuration, i.e., either a split- 〈100〉 interstitial (which our results favor) or a bond-centered interstitial. The predicted minimum-energy configuration changes with charge state, suggesting that the interstitial in the diamond lattice is a possible example of the Bourgoin mechanism of athermal migration of a defect in the presence of ionizing radiation.

Ua77/1 Western Alumnus, Vol. 43, No. 2, Wku Alumni Association

WKU Administration Documents

WKU alumni magazine. Features the following articles:

• Armstrong, Don. Engineering Technology Accredited
• Martin, Vernon & Don Armstrong. Public Affairs Aids Counties
• Distinguished Alumnus Julian Goodman
• Gray, David. WKU Physicist Invents Ultraviolet Dosimeter - William Buckman
• Richards, Jim. Why Recruit the Junior Colleges?
• Pageantry, Nostalgia & Victory - Homecoming
• Just, Paul. The Red and Gray Orchestra
• Ivan Wilson Center for Fine Arts, Dedication
• Hood, Gordon. The Ivan Wilson Center
• Downing, Dero. A Dedication Response
• Downing, Dero. Awareness & Willingness
• Dickey, Debbie. A Renewal of the Spirit
• Sutherland, David. Appalachia, A Stronghold of Early American Folk Culture
• Cann, Kenneth. If It's Guatemala …

Autoionization Of He And Autodetachment Of He- Following Bombardment By H+, H2+, He+, And He Atoms, F. D. Schowengerdt, S. R. Smart, M. Eugene Rudd

M. Eugene Rudd Publications

Presented here are experimental results of a study of the systematics of electron emission from discrete states of He and He- as produced by H⁺, H₂⁺, He⁺, and He impacts. The results were obtained by energy analysis of the electrons emitted at angles of 10° to 160°. Projectile energies ranged from 20 to 150 keV. Differential and integrated cross sections are presented for emission of electrons from the 2s² (¹S), 2s2p(³P), the sum of the 2p² (¹D) and 2s2p(¹P) autoionizing levels of He, …

Projected Hartree Product Wavefunctions. Viii. Relationship Of Dods And Scf Orbitals For Be, Gordon A. Gallup

Gordon Gallup Publications

Projected Hartree product wavefunctions. VIII. Relationship of DODS and SCF orbitals for Be

Ionization‐Enhanced Diffusion: Ion Implantation In Semiconductors, J Bourgoin, David Peak, J W. Corbett

All Physics Faculty Publications

A model for the diffusion of implanted interstitials during implantation is introduced and shown to be able to account for the tails observed in ion profiles. It is argued that mechanisms of ionization‐enhanced diffusion can explain some of the anomalous diffusion mechanisms observed in semiconductors. Indications for the existence of such mechanisms in the field of ion implantation in semiconductors are discussed.

The Design And Calibration Of A Vibrating Sample Magnetometer, Donald Dwight Hoffman

Masters Theses

"The design and calibration of a vibrating sample magnetometer is described. The sample motion was in the direction of the external magnetic field which was produced by a superconducting solenoid. The maximum external magnetic field was 70 kilogauss. Sample temperature could be varied from 77°K to 1000°K with a vacuum jacketed furnace. The maximum temperature was obtained with approximately 27 watts. The instrument was calibrated to 1% with a spherical nickel sample"--Abstract, page ii.

The Contribution Of Phonon-Induced Tunneling To Donor Esr Spectral Narrowing In Semiconductors, David Lawrence Meier

Masters Theses

"The narrowing of donor electron spin resonance spectra with increasing donor concentration N_D and increasing temperature T has been observed in semiconductors in the past. One proposed explanation for this phenomenon has been narrowing due to electron motion caused by phonon-induced tunneling (hopping) between donor sites. According to the Anderson narrowing theory, the line width of the narrowed line can be expressed in terms of the average square spread of the non-narrowed spectrum, < H²>_ave, and the average frequency of electron motion, ω_n. Previous work has been done on narrowing by hopping, but rigorous expressions for ω …

Temperature Dependence Of The Formation Of An Amorphous Layer In Ion-Implanted Silicon, Gary Keith Woodward

Masters Theses

"Electron spin resonance (ESR) has been used to study the temperature dependence of the formation of an amorphous damaged layer produced by ion implantation in silicon.

Undoped silicon wafers were implanted with N⁺, Ar⁺, and Kr⁺ ions at 20 keV and dose rates less than .36 µa/cm². Implant temperatures ranged from room temperature to 250°C. ESR measurements were made at room temperature on these wafers. The only ESR signal found was that associated with amorphous silicon. The ESR signal amplitude for a given ion and temperature increased approximately linearly with dose up to …

Absolute Differential Elastic And Inelastic Cross Sections In 25-140 Kev He⁺ + He Collisions, Victor Pol

Doctoral Dissertations

"The UMR heavy-ion energy-loss spectrometer has been modified to study the angular dependence of elastic and inelastic scattering for 25-140 keV He⁺ incident on He. The data were obtained as energy-loss spectra at angles from 0 to 7.3 x 10^-3 rad (c.m.) with energy-loss resolution of 0.6 to 1.0 eV and angular resolution of 1.2 x 10^-3 to 2.4 x 10^-3 rad (c.m.). From the spectra we have calculated average differential cross sections for elastic scattering, direct excitation of the individual He(n=2) states and direct excitation of the He⁺(n=2) states. By integrating the differential …

Auger Satellites Of The L₂₃ Auger Emission Bands Of Al, Si, And P, John Junior Melles

Doctoral Dissertations

"In this study a detailed investigation of the high energy satellites of the L₂₃ Auger emission bands of Al, Si, and P was made. The satellites are interpreted as arising from double ionization of the L₂₃ shell rather than from a plasmon gain process. The parent-satellite energy separations, ΔE, between like structures were determined and were found to be consistently smaller than the volume plasmon energies measured for the same samples. A comparison of Si and SiO revealed no evidence that ΔE for Si is dependent on the volume plasmon energy of the sample.

The satellite threshold excitation …

A Study Of Gas-Surface Interactions Through Sticking Coefficient, Condensation Coefficient And Sublimation Rate Measurements, Charles E. Bryson Iii

Doctoral Dissertations

"The behavior of the sticking coefficient of CO₂ on an H₂O substrate as a function of time is interpreted in terms of a microscopic nucleation theory. For a substrate temperature near 75 K and an incident flux near 10¹³ molecule cm⁻² sec⁻¹, a critical cluster size of four molecules and and activation energy of nucleation of 22 ± 2.4 Kcal mole⁻¹ is obtained. The analysis treats the nucleation processes as continuous rather than as a discontinuous process at some critical temperature.

In addition the same molecular beam apparatus used for the above experiment was used to measure the condensation …

A Stochastic Theory Of The Stepwise Growth Of Ice Crystal Surfaces, Andreas Kasimir Goroch

Doctoral Dissertations

"Previous theories have had limited success in explaining the presence of a peak in the behavior of the rate of advance of a step on an ice crystal surface with respect to temperature. In the present work we examine the temperature dependence of the advance of steps on the basal face of an ice crystal from several points of view. An alternate derivation is presented for the random motion of adsorbents on a cubic lattice with absorbing points, and this theory is applied for the advance of a step on an ice surface. The velocity of step advance according to …

Some Implications Of The Second Law Of Thermodynamics, Nancy Barklage

Student Scholarship

Thermodynamics is the branch of science concerned with energy changes that accompany all natural processes. While there are three primary laws, the Second Law of Thermodynamics is the most far-reaching due to its influence on the direction of time and its philosophical implications for life and the universe. Central to this law is the concept of entropy, which serves as a measure of disorder or randomness within a system. All spontaneous processes are irreversible and naturally progress toward a state of maximum entropy and lowest energy. 

One significant implication of the Second Law involves the origin of life. While the …

Appendix A: The Use Of The Personalized System Of Instruction (Psi)

Calculus-Based General Physics

STUDY MODULES FOR THE USE OF THESE CBP MODULES

Recommended

1. What is the Philosophy of PSI?

2. How Do I Manage This System?

3. The Care and Feeding of Student Tutors

Optional

4. How to Plan the Content of a Keller Plan Course

5. How to Design a Study Module

6. How to Write Learning Objectives

The Experimental Determination Of The Eddy Current Effects On The Nuclear Magnetic Resonance Of Aluminum Wires, Mark Allen Butterworth

Dissertations and Theses @ UNI

An experimental determination has been made of the eddy current effects on the nuclear magnetic resonance lineshapes of Al²⁷ wires. Eddy currents in the metal result from the applied radio frequency (r-f) field used to obtain resonance. Due to the induced eddy currents, this r-f magnetic field is attenuated and its phase is shifted as it progresses toward the center of the sample. A quantity defined as the skin depth is a measure of this attenuation. As a result of the attenuation and phase shift of the r-f magnetic field, the resultant lineshape of a given mode of the resonance …

Antiferromagnetic To Paramagnetic Transition In Fe2+: Mnf2 In External Magnetic Fields, C. R. Abeledo, Richard B. Frankel, M. A. Weber, A. Misetich

Physics

Mössbauer effect measurements across the antiferromagnetic to paramagnetic phase boundary in Fe²⁺ : MnF₂ in external magnetic fields are reported. From the data, J(Mn-Fe)= -1.7 cm^-1. The phase boundary is found to vary as Ho2, as in pure MnF₂.

Logical Transition From Magnetic Poles To Current Loops, H. E. Mccloud

Journal of the Arkansas Academy of Science

Consideration of the relationship between the magnetic field produced by a magnetic shell and that produced by a current loop requires the evaluation of the line integral ɸH̅ • dl̅, where a portion of the path must cross the dipole layer. The correct line integral to be evaluated must be ɸB̅ • dl̅. The evaluation of this integral leads immediately to the correct Maxwell equation in ∆ x H̅. Gaussian units are used.

Far Infrared Absportion Of Fe(2+) In Kmgf3, R. B. Frankel, C. R. Abeledo, A. Misetich

Physics

Far infrared absorption in cubic KMgF₃ doped with Fe²⁺ is reported . A line is observed at 87cm−1, which is assigned to the (Γ5g → Γ3g, Γ4g) transition in the Fe²⁺. The reduction in the spin-orbit coupling from the free ion value has been predicted by Ham, Schwarz and O'Brien.

Geophysical Institute Annual Report 1972-73, Geophysical Institute

GI Reports

The 1972-73 Geophysical Institute Annual Report presents an overview of the year’s scientific research achievements across the Institute’s disciplines, alongside operational summaries covering finances, administrative changes, and other key activities.

Charge Transfer Between Oˉ Ions And O₂ Molecules In The Ground State And Singlet Delta Excited State, Ronald Floyd Mathis

Doctoral Dissertations

"A crossed-beam apparatus has been built and used to study charge transfer between O⁻ ions and O₂ molecules in the ground state and in the metastable, singlet delta, excited state. The energy of the incident ions ranged from 10 to 10,000 eV.

The cross section for charge transfer between O⁻ and ground state O₂ was found to peak at about 5 keV, as predicted on the basis of the Rapp and Francis theory. At the lower energies there is good agreement with the previous measurements of Snow et al., and Rutherford and Turner, who also used crossed beam techniques. The …

Extension Of Belyaev-Zelivinski Method Of Rotation As Intrinsic Nuclear Excitation, Jeffrey W. Gray

Graduate Dissertations and Theses

The method of Belyaev and Zelevinski for handling the rotational collective states of deformed nuclei has been extended. It is shown how a [J(J+1)]² term naturally occurs in the energy spectrum of a rotational band for even-even nuclei. This is accomplished by modifying the assumption that Belyaev and Zelevinski imposed on their |n> states. This leads to a definite relationship between the coefficient of the J(J+1) and [J(J+1)]² terms in the energy spectrum. This technique is applied to a single isolated j-level and to an arbitrary level scheme.