Physical Sciences and Mathematics Commons^™

Polynomial And Rational Fraction Representations Of A Diatomic Molecular Potential, Paul R. Findley

Physics & Astronomy ETDs

A method is presented for approximating a diatomic molecular vibrational potential by fitting to modified forms of the potential. Power's numerical Born-Oppenheimer potential for the H₂⁺ electronic ground state is the potential used in this thesis. The modification procedure is to multiply the potential by various powers of the internuclear separation. This removes the troublesome Coulomb pole at zero internuclear separation. Graphs of the modified forms are presented. Polynomials were fitted directly to the potential, to the modified forms, and to the pure electronic energy. Comparisons are made among the various representations of the potential obtained from the …

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 …

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 …

Plasma Sheath Analysis By Computer Simulation, Leo J. Rahal

Physics & Astronomy ETDs

The time development of a fully ionized, dense two-component plasma is investigated through the use of a one-dimensional particle simulation code. The plasma is initially composed of two distinct regions. One region is a uniform plasma in which electrons and ions are at the sane temperature and have no electric fields due to charge separ­ation. The other region contains a charge separation of electrons and ions resulting in an electric field. There also exists an electron current which produces a confining magnetic field. This is the sheath region between the neutral plasma and the confining magnetic field. The simulation occurs …

Infrared Observations Of Hii Regions And Comet West, Paul A. Heckert

Physics & Astronomy ETDs

In Chapter 1, I outline the methods of making ground-based infrared observations. I concentrate on the observational procedures rather than the instrumental design. Near-infrared observations of S 156A, _S 158A, S 159A, S 162A₁, S 228, and G 45. 5 + 0 .1 (#2) made with a beam size of ̴1 are used to estimate the total near infrared flux. After correcting for the line of sight extinction the near infrared luminosities are greater than the Lyman-α luminosities inferred from radio observations. A strong double peaked infrared source was discovered near the region of G 25.3-0.1. The infrared …

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 …

General Geodesic Motion In The Extended Kerr Manifold, Richard H. St. John

Physics & Astronomy ETDs

The timelike and null geodesics in the Kerr metric describe important properties of the space surrounding a rotating black hole. The general characteristics of these geodesics, with an emphasis on those on the axis of symmetry and the equatorial plane, are found in this paper. On the axis of symmetry, the behavior of all timelike and null geodesics is completely described. The accessibility of various spaces added for geodesic completeness in the extended manifold is found by making local observations of geodesics in one coordinate patch from geodesics in another. The analysis on the equatorial plane shows that for a …

A Method For Measuring The Electrical Conductivity Of A Shocked Liquid, Richard James Hassman

Physics & Astronomy ETDs

Development of a simple technique for the measurement of the gross electrical conductivity of a shock compressed liquid is attempted. A cell containing the sample is constructed from glass cylinders and aluminum foil. The foil is sandwiched between two cylinders of the same diameter to form a two compartment cylinder. The cylinder is mounted on a metal target plate. With both chambers of the system full of liquid, only insignificant reflections can arise from the sample-foil interface. A voltage is placed across the cell between the foil and the target plate, and the change in voltage as the shock front …

A Photographic Study Of The Infrared Oh Airglow, G. C. Loos

Physics & Astronomy ETDs

OH airglow is due to the rotational-vibrational transitions of the hydroxyl radical. Previous efforts to find the airglow's emission height in the atmosphere are discussed. Photography of the infrared airglow with a fast 35mm camera and Eastman Kodak high speed infrared film is described and a method for triangulating emission heights by two station photography is explained. The techniques for reduction of film data to height measurements and velocity measurements are presented. Observations are reported concerning the frequency of occurrence of bright spots and other features on the OH background and the intensity of the airglow as a function of …

Dynamic Impulse Calibration Of Sheet Loaded Explosive, William James Johnson

Physics & Astronomy ETDs

In the past, experimenters have used Sheet Loaded Explosive (SLE) to simulate the damage caused by x-rays to an ICBM as the result of a nuclear burst from an ABM. One of the attractive features of SLE is that it can also provide high impul3e levels for structural damage studies. Previous measurements of the usual shock parameters such as peak overpressure, ietonation velocity, and shock front definition with short time interval pressure transducers were not suitable for total impulse measurements. The High Explosive Impulse Responder (HEIR) was developed to fill the need for a simple, reliable and economical total impulse …

First Measurements Of Earth Albedo Neutrons In Space, James R. Place

Physics & Astronomy ETDs

NASA satellite OSO-6 carried as part of its payload a proton recoil telescope capable of detecting neutrons between 40 and 200 MeV with directional discrimination. Sixteen months of data from this instrument were analyzed with a view to determining properties of the earth albedo neutron flux above the atmosphere.

The variation of albedo neutron flux with geomagnetic latitude was found to be 1:4 between 0° and 40°. The angular distribution shows that about 40% fewer neutrons come upward from directly beneath the satellite compared to the number coming from a direction tangential to the top of the atmosphere. These results …

Development Of The Oso-6 High-Energy Neutron Detector And Correlation Of Measured Solar Neutron Fluxes To Solar Flares, Frederick Young

Physics & Astronomy ETDs

In an attempt to understand certain of the high energy processes that occur in the solar and terrestrial atmospheres and the interplanetary medium a detector of 20 to 160 MeV neutrons had been designed and constructed for inclusion in the NASA Orbiting Solar Observatory, Satellite OSO-G, which was launched into a near circular orbit at approximately 500 km altitude in August 1969. Both the angle of incidence and the energy of the neutron are determined by a telescopic arrangement of four scintillation plastic counters (Pilot B; hydrogen to carbon ratio 1:1) which generates proton recoils and provides pulse heights for …

Cellular Absorbed Dose Spectrometer (Cads) Data Reduction And Analysis., John T. Cervini

Physics & Astronomy ETDs

A detailed description of a space qualified linear energy transfer (LET) spectrometer is presented. The Cellular Absorbed Dose Spectrometer (CADS) is a prototype instrument which was launched on March 17, 1969 into an elliptical orbit. Its purpose was to obtain the first successful LET measurements in space; and, thereby provide additional data to assess the biological hazards of the near earth space environment, especially during periods of in­creased solar activity.

The physical processes that take place in the CADS in­strument are discussed, and a definition of linear energy transfer is given, as well as its relation to dE/dx. The performance …

Measurement Of The Average Solar Neutron Flux And Its Correlation With Solar Activity, Pyung Syk Ro

Physics & Astronomy ETDs

Data from the University of New Mexico High Energy Neutron Detector flown on NASA satellite OSO-VI arc analyzed with the aim of detecting neutrons from the sun. The detector is a proton recoil telescope capable of directional discrimination and responsive to neutrons of energies between 20 and 200 MeV with an effective average efficiency for this analysis of 10^-4 and an effective area of 80cm². The detector was located in a wheel compartment of OSO-VI and scanned the sun once per revolution of the wheel at a rate of 30 rpm. The satellite was launched on August …

Increasing The Efficiency Of A Surface Ionization Mass Spectrometer, Thomas Curtis Adams

Physics & Astronomy ETDs

An Avco surface ionization mass spectrometer (model 90,000) was installed at the Los Alamos Scientific Laboratory in February, 1968. Since that date this machine has been used as a production instrument for the isotopic analysis of uranium and plutonium samples. During 1969, it was realized that a problem inherent in the ionization mechanism of the instrument was degrading the accuracy of results, and that the number of man-hours expended in reducing data had become excessive. As soon as this situation became apparent, corrective action was initiated to reduce the effect of the ionization problem and to decrease the amount of …

Intensity Ratios For Polarized Refracted Light Near The Critical Angle., Stephanie Layne Moore

Physics & Astronomy ETDs

It was undertaken to investigate the intensity ratio of refracted light polarized parallel and perpendicular to the plane of incidence. The primary object of the experiment was to obtain this ratio for light incident at very nearly the critical angle on a water-air interface, the light having first passed through the water. A laser was used to produce the light beam and the experimental results were compared with the theory propounded by Fresnel for infinite plane waves and elsewhere asserted to hold for bound plane waves. As this theory predicted a ratio of the square of the refractive index (n) …

Linear Pulsation Analysis Of Cluster Cepheid Variables, Charles E. Needham

Physics & Astronomy ETDs

Models for thirteen classical Cepheids found in galactic clusters or associations are analyzed. The models are calculated using the most recently published photometric data and theoretical evolutionary tracks. The linearized equations of mass, momentum and energy conservation are solved subject to an infinitesimal radial perturbation of each equilibrium model. The equations are first solved in the adiabatic approximation. This solution is then used as the initial value for the iterative solution of the non-adiabatic equations. The linearized analysis provides information on pulsation periods of fundamental and harmonic modes, stability against pulsations and phase differences between various physical parameters, such as …

Propagation Of Ultrasound In Plastic Crystals, Carl E. Scheie

Physics & Astronomy ETDs

The study of the organic solid state, and in particular of plastic crystals, is a relatively new branch of physics (1,2). Timmermans first surmised the existence of these solids from the anomalous values of the entropies of fusion. The solids possess many of the characteristics of liquids. They are easily deformed by pressure and they show dielectric properties that can be described on the basis of rotation of the molecules in their lattice positions. Still they have a definite crystal structure. Thus, even though the molecules are not symmetric, they appear to be to some degree because of the rotation. …

A Study Of The Sidereal Diurnal Variations Of Cosmic Rays Underground., Albert Brunsting

Physics & Astronomy ETDs

The sidereal diurnal variation of cosmic rays has been measured using underground (40 m.w.e.) meson telescopes located near Albuquerque, New Mexico (35.20°N, 106.41°w) and at Chacaltaya, Bolivia (16.31°s, 68.15°w). Each ofthe two locations has telescopes which scan the vertical and four inclined directions.

Two and three complete years were used for the tele­scopes at the Bolivia and New Mexico locations respectively. The average solar diurnal variations were calculated for each telescope for each month. Based on these monthly averages, the sidereal diurnal variations were computed. A correction was made in the analysis for any yearly modulation of the solar diunal …

A Shock Tube Study Of Recombination In The Lean Hydrogen-Oxygen Reaction Based On The Infrared Emission From Water Vapor, Larry S. Blair

Physics & Astronomy ETDs

ABSTRACT

Recombination in the hydrogen-oxygen reaction has been studied by monitoring the growth of infrared emission at 2.7 microns from water vapor as it is formed behind incident shock waves. Experiments were carried out in gas mixtures with hydrogen-to-oxygen ratios between 1.0 and 0.33 and temperatures between 1435° and 1868°K. Reactants were diluted with 92-98% argon. The validity of the transparent gas approxi­mation (emission intensity proportional to (H20]) and the relationship between emission intensity and temperature were established by cali­bration experiments in which mixtures of water vapor and argon were shock-heated to temperatures between 1328° and 1982°K. Analysis of H20-emission …

Meteorological Effects On Cosmic Rays At Albuquerque, New Mexico., David Nason Glidden

Physics & Astronomy ETDs

Ground-based observations of cosmic-ray intensity have the disadvantage of being more sensitive to variations of atmospheric temperature and pressure than to the more interesting variations in the primary cosmic radiation. It is, therefore, imperative to correct the recorded cosmic-ray intensity for variations of atmospheric origin before studies can be made of the smaller variations of the primary cosmic ray intensity.

In this thesis an attempt has been made to remove the variations of atmospheric origin from the cosmic-ray intensity recorded simultaneously by a neutron monitor and a meson telescope located at Albuquerque, New Mexico. It was found that the neutron …

Theoretical Analysis Of The Vibrations And Rotations Of The B¹[Sigma][Mu] State Of The Hydrogen Molecule, Sandra Zink Moody

Physics & Astronomy ETDs

Theoretical calculations of the rotational-vibrational constants of the B¹Σ⁺_u state of H₂ were made using the Dunham analysis and by fitting equations to energy eigenvalues. The potential energy function for the nuclei used in the calculations was computed by W. Kolos and L. Wolniewicz using the variational technique. The power series used in the Dunham analysis made use of Stirling's central difference interpolation polynomial. The equilibrium separation R_e found from the Born-Oppenheimer potential is 2. 42916₅ atomic units, differing from the Kolos-Wolniewicz value of 2.4288. Adiabatic corrections were taken into account through a …

Response Prediction For The Oso-G Satellite Solar Neutron Instrument By Matrix Methods., John Coalmer Conklin

Physics & Astronomy ETDs

Properties of the University of New Mexico’s solar neutron instrument for use on the NASA 0S0-C satellite were investigated. A sensor model was developed by use of two computer codes. First, the total efficiency of the converters was calculated by a simulation code with a resulting total efficiency at 100 Mev of approximately two per cent of which four-fifths was carbon recoil contribution.

Second, geometry properties of the instrument were provided by a Monte Carlo program, with maximum geometry efficiency equaling about fourteen per cent. These were combined to give a total response profile for the instrument which was expressed …

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 …

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 …

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

Physics & Astronomy ETDs

No abstract provided.

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 …