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A Study Of The (T, P) Reaction On 90,92,94,96zr And 122,124sn, Jerome G. Beery

Physics & Astronomy ETDs

A study is made of the (t, p) reaction on targets of ^90,92,94,96Zr and ^122,124Sn. The purpose of the study is to investigate the nuclear energy levels that are populated by putting two neutrons into a target nucleus. The targets were bombarded with 20-MeV tritons from the Los Alamos tandem Van de Graaff facility. Protons were detected with solid-state counter telescope and the data was recorded with an online digital computer. Energy spectra were taken for each of the targets utilizing a magnetic spectrometer in order to obtain excitation energies with an accuracy of ± 10 keV. The …

Numerical Evaluations Of The Virial Integrals, Li-Hwa Lee

Masters Theses

No abstract provided.

Population Excitation Mechanism Of The First Negative System Of Nitrogen, Robert Lynn Bridigum

Physics Theses & Dissertations

The photoionization process of nitrogen was studied using the helium resonance line (584 Å) to excite nitrogen from the ground state to an excited ionic state. The transitions from the second excited state of the ion, N+2B²Σt+u to the ground state of the ion, N+2X²Σ+g, were of particular interest. The nitrogen fluorescence was spectrally analyzed in the region from 2000 Å to 5000 Å , to determine the most prominent bands of the first negative system. Two unresolved bands were observed: the v = 0 to v =.O band at 3914 Å, and the …

Formation Of Etchable Tracks In Dielectrics, Robert Katz, E. J. Kobetich

Robert Katz Publications

It is proposed that etchable damage is produced in dielectrics by energetic charged particles when a critical dosage of ionization energy is deposited at a critical distance from the ion's path by secondary electrons. Within the critical cylinder, molecular fragments more soluble than the parent molecule are formed. The radius of the critical cylinder is taken to be approximately 20 Å, as is appropriate to the passage of the etchant along the track and the diffusion of reaction products back to the surface. At the critical radius the dosage approximates doses producing bulk damage under γ irradiation. The proposed criterion …

Response Of Nai(T1) To Energetic Heavy Ions, Robert Katz, E. J. Kobetich

Robert Katz Publications

Experimental values of the relative heights of scintillation pulses generated in NaI(T1) crystals, by heavy ions (Z>5) of energy 1-10 MeV/amu, agree well with computed relative cross sections for photon production, from a theory based on the assumption of a one-hit response to the spatially distributed dose of ionization energy, and a characteristic dose of 4x10⁷ erg/cm³ for this material Discrepancies between theory and experiment for He bombardments arise from the theoretical neglect of the nonlinear dose variation over the sensitive volume surrounding each TI atom. Similar discrepancies arising from the neglect of molecular volume occur …

Width Of Heavy-Ion Tracks In Emulsion, E. J. Kobetich, Robert Katz

Robert Katz Publications

Profiles of the solid core of long, flat, ending tracks of heavy primary cosmic rays in Ilford G-5 emulsion have been measured by manually tracing their enlarged (3500X) photographic image. These measurements agree well in the ending 3000 μ of residual range (β <0.3) with a reformulated theory of track width based on computation of the spatial distribution of ionization energy. The measured core width in G-5 emulsion is the sum of the sensitized cylinder diameter, at which 6000 erg/cm³ of ionization energy is deposited by δ rays, and the diameter of a developed grain.

Solid State Electrolysis Of Yttria Stablized Zirconia, John Newman

Masters Theses & Specialist Projects

Zirconium dioxide, or zirconia, is seemingly an ideal refractory oxide, having a high melting point (2680°C), low thermal expansion and also a considerable resistance to most forms of chemical attack. Early researchers soon found that zirconia, in the pure form, was actually of very limited use as a refractory because of sudden and disruptive volume changes accompanying a change in crystal structure which occurs at a temperature of about 1100 o C. It was discovered that this crystal structure change could be suppressed by the addition of one of a number of alkaline earth or rare earth oxides. These additive …

Possible Trivacancy Contribution To Ionic Conductivity, Robert Fuller, M.H. Reilly

Robert G. Fuller Publications

Fuller and Reilly [1], Fuller, Reilly, Marquardt and Wells [2], and Allnatt and Pantelis [3] have recently reported the results of measurements of the intrinsic electrical conductivity σ of RbCl, KCl and NaCl, respectively. All of these results showed an anomalous behavior of the log (σT) vs. T^-1 plot at temperatures near the melting points of the various crystals. It is the purpose of this note to discuss the suggestion [4] that the anomaly may be due to a trivacancy mechanism.

The plots of the log (σT) vs. T –1 were found to have too …

Mössbauer Studies Of Impurity Tin Atoms In Indium, Richard L. Smith

Masters Theses

No abstract provided.

Positron Annihilation In Single Crystal Zinc At 250 Degrees Centigrade, Jon Wayne Swanson

Masters Theses

No abstract provided.

X-Ray Irradiation Studies Of Lybian Desert Glass And Sand, Magdi M. Nasrallah

Archived Theses and Dissertations

No abstract provided.

The Motion Of A Charged Particle In The Field Of A Magnetic Dipole, E. Royce Fletcher

Physics & Astronomy ETDs

The principal difficulties encountered in attempting to solve the general problem of the motion of a non-relativistic, non-radiating charged particle in a magnetic field which varies position and time, are associated with the induced electric field. That is to say, the time variation of the magnetic field produces an electric field which also acts on the particle. Both these fields must be known as functions of time and position if the equations of motion are to be determined exactly.

The Spectroscopic Constants Of The Ground Electronic State Of Hydrogen Molecular Ion, Bertle Daniel Hansen

Physics & Astronomy ETDs

ABSTRACT

An accurate theoretical determination of certain vibration rotation properties of the hydrogen molecular ion is made. Two different methods of analysis are used in the determination of these properties. First, an energy equation for diatomic molecules is

fitted directly to theoretical vibration and rotation eigenenergies of the ground electronic state of H+2 calculated by J.M. Peek. These eigenenergies include adiabatic corrections determined by w.Kolos. Second, a fixed-nucleus potential for the ground electronic state of H+2, calculated by J. M. Peek which did not include adiabatic corrections, is expanded in a power series in the neighborhood of the equilibrium internuclear …

Pressure And Temperature Dependence Of The Acoustic Velocities In Polymethylmethacrylate, James Russell Asay

Physics & Astronomy ETDs

The acoustic velocities in polymethylmethacrylate have been measured with an ultrasonic pulse echo technique as functions of frequency, temperature and pressure. At atmospheric pressure, data on the velocities and attenuation coefficients were obtained over the range of temperature from 22°c to 75°c and for the frequency range of 6 to 30 MHz. At the temperatures of 25, 40, 55 and 75°c, the pressure dependence of the longitudinal and shear velocity was obtained to 150,000 psi at a frequency of 6 MHz. From the frequency measurements of the velocities, the complex elastic moduli in polyrnethylmethacrylate were calculated at room temperature. The …

Dose And Depth Dose Measurements On The Sixth Gemini Flight, A Comparison With The Gemini-4 Radiation Measurements, Marion F. Schneider

Physics & Astronomy ETDs

Two tissue-equivalent ionization chambers were flown behind 0.4 gram/cm.² and 2.5 grams/cm.² of shielding inside the Gemini-6 spacecraft. The instruments measured the radiation levels resulting from primary cosmic radiation and the trapped particle environment of the earth's Van Allen belts. Each sensor was constructed from a special tissue-equivalent plastic with radiation cross sections that closely match standard muscle tissue for the many complex types and energies of radiation encountered in space. The design of the sensor and logarithmic electrometer preamplifier are described in detail. The calibration and directional sensitivity of the sensors with cobalt-60 and cesium-137 gamma radiation …

Surface Resonances In High Frequency Scattering From A Nearly-Sharp Three Dimensional Well., Jaime Marcelo Wong Luy Tay

Physics & Astronomy ETDs

A computational investigation of the effect of a surface transition region of relative half-width δ on certain surface resonances in high frequencies scattering from a nearly-sharp, three dimensional spherical well is performed by the method of partial wave analysis.

An incident beam of particles, described by a scalar plane wave, interacts with a fixed scattering center represented by a dielectric sphere of index of refraction 1.333, with a very small transition region in the boundary of the well, described by an odd polynomial function of third order. This is the scalar-wave analogue to the more complicated problem of scattering of …

Lattice Dynamics And Second-Order Raman Spectrum Of Csf, John R. Hardy, Arnold Karo

John R. Hardy Papers

Results are presented for a precise calculation, based on the deformation dipole model with short-range repulsive interactions between second-neighbor negative ions, of the normal-mode frequency distribution of CsF. The extreme properties of this crystal are reflected in the unusual appearance of the distribution. From these results, we can also predict the form of the second-order Raman spectrum of CsF for two alternative assumptions regarding the Raman polarizability tensor. Both spectra are unusual in that they consist almost entirely of very sharp, clearly separated lines. Furthermore, the spectra corresponding to these two assumptions are very different and should be easily distinguishable …

Far Infrared Properties Of Lattice Resonant Modes. I. Isotope Shifts, Roger D. Kirby, I.G. Nolt, R.W. Alexander Jr., A.J. Sievers

Roger Kirby Publications

The frequency shift of a lattice resonant mode associated with the isotopic substitution of an impurity ion has been measured for NaCl: Cu⁺, KI: Ag⁺, and KBr: Li⁺. For all three systems, the experimental frequency shifts can be described satisfactorily by an Einstein oscillator representation for the resonant mode with the oscillator mass set equal to the impurity-ion mass. The model of Benedek and Nardelli and also Klein does not account for the experimental results of NaCl: Cu⁺ or KBr: Li⁺. The inclusion of anharmonic forces does improve the agreement between …

Magnetic Hyperfine Structure In 125Te, Richard B. Frankel, J. J. Huntzicker, D. A. Shirley, N. J. Stone

Physics

Mössbauer spectra of ¹²⁵TeFe with improved resolution yield μ(35.5 keV) = +0.60 ± 0.02 nm. The effect of this value on hyperfine spectra of ¹²⁵Te are discussed.

Associative Detachment: H+Hˉ→₂*+E, Joseph C.Y. Chen, Jerry Peacher

Physics Faculty Research & Creative Works

The process of associative detachment in the (H,H^-) collision system is investigated at energies below 12 eV. In this energy region, the interaction potential between H and H^- has recently been determined. The energy dependence of the cross section is calculated with explicit allowance for the production of "hot" hydrogen molecules. It is observed that associative detachment provides a possible mechanism for generating an inverted population of the residual molecule such as H₂.

Angular Correlation Study Of The 105 Kev Level In Gd155, John B. Gouvas

Masters Theses

No abstract provided.

New Superconvergent Dispersion Relations For The Forward Πn Crossing-Even Amplitude, David J. George, Barbara N. Hale, Arnold Tubis

Physics Faculty Research & Creative Works

A Liu-Okubo-type dispersion relation is derived for the crossing-even pion-nucleon forward elastic scattering amplitude T⁽⁺⁾. Two subtractions are made, one at the physical scattering threshold and the other at a previously determined zero of T⁽⁺⁾ on the imaginary axis of the complex ω (pion lab energy) plane. The dispersion relation is well satisfied over the whole allowed range of the Liu-Okubo parameter. Moreover, it is nearly saturated by low-energy scattering for a considerable range of the parameter. It should thus serve as an extremely sensitive test of the low-energy scattering data when such data become more accurately …

Electrical Conductivity Of Potassium Chloride, Robert Fuller, Michael H. Reilly, Charles L. Marquardt, John C. Wells

Robert G. Fuller Publications

The electrical conductivity of potassium chloride is discussed within the framework of a four-defect model of the crystal. The four defects are mobile anion and cation vacancies and immobile divalent cation impurities and divalent cation impurity-cation vacancy complexes. The Teltow formulation of the four-defect mode1 fails to describe precisely the measured electrical conductivity of KCl over the entire intrinsic and extrinsic range.

The Red Leak And Its Effect In Ultraviolet Photometry., Jeffrey David Colvin

Physics & Astronomy ETDs

The red leak in the red 􀀉and of the ultraviolet filter (Corning #9863) of the standard UBV photometric system is investigated. Astronomical photometry is discussed in general, and UBV photometry in particular. The photometric system used in this work is also discussed, including telescope, phototube, filters, and amplifier. The standard filters of the UBV system are used, but the standard phototube of this system is not used. An analytic representation of the red leak magnitude correction is developed.

Sixty-five measurements were made for a wide variety of stars from spectral class B3 to spectral class M2. The red leak correction …

Interaction Potential Between The Ground States Of H And Hˉ, Joseph C.Y. Chen, Jerry Peacher

Physics Faculty Research & Creative Works

An investigation of the interaction potential for H and H^- in both ungerade and gerade modes is carried out by a semiempirical method in which the recently observed isotope effect in dissociative attachment of electrons to hydrogen molecules is used. The interaction obtained is complex, and the imaginary parts of the interaction account for electron emissions during the course of the interaction. A comparison of the present result with other calculations is presented. The isotope effect in dissociative attachment is also discussed. It is shown that the ratios of the survival probabilities alone do not provide an adequate approximation …

A Method For Measuring Magnetization To High Pressures, C. R. Johansen, Mark H. Nelson, J. H. Gardner

Faculty Publications

A partially successful attempt has been made to measure the magnetic moment per unit volume of ferromagnetic materials as a function of pressure to the 100-kbar region. The apparatus, an early version of which has been described previously, consists basically of two opposed Bridgman flat anvils of alumina. One anvil also acts as a dielectric-filled microwave resonant cavity for an x-band spectrometer, allowing electron spin resonance studies to be made to high pressure. The sample to be studied is placed in contact with the anvil-cavity and covered with a pressure-transmitting medium which in turn is encircled by a flat pyrophyllite …

Projected Hartree Product Wavefunctions, Gordon A. Gallup

Gordon Gallup Publications

A method for performing a restricted configuration interaction calculation on atoms or molecules based on the use of Young operators from the symmetric groups is discussed and its relation to some other types of calculations is pointed out. The method in its most general form can be said to be an extension of the independent particle approach which represents the wavefunction in terms of the n best possible one-particle orbitals for the n-particle system. Illustrations are given for the hydrogen molecule, the helium atom, and the allyl radical. ©1968 American Institute of Physics

Mössbauer Effect In 57Fe In Copper And The Spin‐Compensated State, B. B. Schwartz, D. J. Kim, Richard B. Frankel, N. A. Blum

Physics

The results of Mössbauer experiments on dilute Fe in Cu in high external magnetic fields (42–146 kOe) are presented here as evidence for significant destruction of the spin‐compensated state by a magnetic field for which μH₀∼kT_K, where kT_K is on the order of the energy change associated with the formation of the spin‐compensated state.

Magnetic‐Field Dependence Of The Hyperfine Field At Fe In Dilute Fe-Pd Alloys, N. A. Blum, Richard B. Frankel

Physics

No abstract provided.

Electron-Impact Lonization Cross Section In Cesium, Kaare J. Nygaard

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The total ionization due to the passage of an electron beam in cesium vapor has been measured with a Tate and Smith-type apparatus. The retarding potential difference method was used in the electron gun to obtain energy resolution better than 0.1 eV. The density of Cs atoms was determined from the Taylor and Langmuir formula and also measured with a surface-ionization detector. The two methods gave the same density to within ±3% when the apparatus was in thermodynamic equilibrium with the Cs reservoir. The cross section for production of Cs+ has been determined from threshold to 100 eV. For energies …