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Full-Text Articles in Physics

Semi-Annual Summary Research Report In Physics, Ames Laboratory Staff, F. H. Spedding Apr 1959

Semi-Annual Summary Research Report In Physics, Ames Laboratory Staff, F. H. Spedding

Ames Laboratory ISC Technical Reports

A semi-annual summary research report in physics for the period of July through December of the year 1958.


The Determination Of Photoneutron Thresholds, William S. Rawls, L. J. Laslett Mar 1959

The Determination Of Photoneutron Thresholds, William S. Rawls, L. J. Laslett

Ames Laboratory ISC Technical Reports

The photoneutron thresholds of twelve nuclides were measured, using the Iowa State College synchrotron and its associated energy control device.


Effects Of Deformation On Superconducting Metals, Victor Walter Hesterman, C. A. Swenson Nov 1958

Effects Of Deformation On Superconducting Metals, Victor Walter Hesterman, C. A. Swenson

Ames Laboratory ISC Technical Reports

An A.C. mutual inductance method was used to measure the effects of deformation on the superconducting critical field curve for tin. The deformation was produced by pushing on the ends of a cylindrical sample which had a length to diameter ratio of unity. It was found that a 2% deformation produced no change in the shape of the critical field curve but only shifted it upward about 1.5 oersteds.


Semi-Annual Summary Research Report In Physics, Ames Laboratory Staff, F. H. Spedding Oct 1958

Semi-Annual Summary Research Report In Physics, Ames Laboratory Staff, F. H. Spedding

Ames Laboratory ISC Technical Reports

A semi-annual summary research report in physics for the period of January through June of the year 1958.


Bibliography Of Titles Of Articles In The Field Of Nuclear Quadrupole Resonance Spectroscopy Of Solids, R. G. Barnes May 1958

Bibliography Of Titles Of Articles In The Field Of Nuclear Quadrupole Resonance Spectroscopy Of Solids, R. G. Barnes

Ames Laboratory ISC Technical Reports

This bibliography lists the titles of literature articles in the field of nuclear quadrupole resonance spectroscopy of solids. This field has been taken to include the area of quadrupolar effects in nuclear magnetic resonance as well as 3 the basic area of nuclear quadrupole resonance in zero magnetic field. Articles published not later than January 1, 1958 have been included. Twenty-one journals are represented, and in addition, eleven books which contain chapters or sections dealing with this subject are included.


The Nuclear Energy Levels And Metastable States In The Deca Of Yb169, George W. Eakins Dec 1957

The Nuclear Energy Levels And Metastable States In The Deca Of Yb169, George W. Eakins

Ames Laboratory ISC Technical Reports

The transitions in the electron capture decay of Yb169 to TM169 have been studied by means of an Intermediate-Image Beta- Ray spectrometer to detect internal conversion electrons, and a scintillation detector to study gamma rays. Transition energies of 8.4, 20.8, 63.1, 93.6, 109.8, 118.2, 130.5, 177.2, 198.0, 240.4, 261.0 and 307.7 kev were measured.


Faraday Cup Monitor For The Iowa State College Synchrotron Electron Beam, Roderick D. Riggs, C. L. Hammer Dec 1957

Faraday Cup Monitor For The Iowa State College Synchrotron Electron Beam, Roderick D. Riggs, C. L. Hammer

Ames Laboratory ISC Technical Reports

The design, construction, and testing of two high energy electron beam monitors are described. The one, a Faraday cup, is an absolute measuring device and the other is secondary emission monitor. The procedure and results necessary to calibrate the secondary emission monitor against the Faraday cup are included. Since the secondary emission monitor is portable, it is an adaptable instrument for the absolute measurement of high energy electron beams after it has been so calibrated.


Shape Of The Phosphorus 32 Beta Energy Spectrum, George B. Henton, B. C. Carlson Dec 1957

Shape Of The Phosphorus 32 Beta Energy Spectrum, George B. Henton, B. C. Carlson

Ames Laboratory ISC Technical Reports

The shape of the beta energy spectrum of P32 was determined by making a least squares fit of the experimental data. This was compared with the shape expected when interference between matrix elements of different orders of forbiddenness is assumed.


Thermomagnetic And Galvanomagnetic Effects, R. D. Redin Sep 1957

Thermomagnetic And Galvanomagnetic Effects, R. D. Redin

Ames Laboratory ISC Technical Reports

A review is given of the various thermomagnetic and galvanomagnetic effects. The coefficients and relations between coefficients are listed for both metals and semiconductors. A quantitative analysis is given of the error in Hall effect measurements owing to non-isothermal conditions.


Ionization Yields For Fission Fragments, Nyle G. Utterback, C. L. Hammer, G. H. Miller Aug 1957

Ionization Yields For Fission Fragments, Nyle G. Utterback, C. L. Hammer, G. H. Miller

Ames Laboratory ISC Technical Reports

The ratio of the ionization produced in stopping a fission fragment to the ionization produced in stopping an alpha particle, R, has been measured in the gases helium, argon, and a helium plus 0.25 per cent argon mixture for the most probable light and heavy fragments. Natural uranium was fissioned by fast neutrons from the D,D reaction. The alpha particles were obtained from the U234 and U238.


Simultaneous Single Element Air Temperature And Velocity Measurements, James E. Benjamin, R. W. Fahien Jun 1957

Simultaneous Single Element Air Temperature And Velocity Measurements, James E. Benjamin, R. W. Fahien

Ames Laboratory ISC Technical Reports

Equations were derived for measuring /gas velocity and temperature simultaneously using a single heated platinum wire as the sensing element. These equations contained four unknown coefficients which were considered constant. These constants were to be determined by calibrating at two known levels of temperature and velocity.


Mass Transfer In Low Velocity Gas Streams, John E. Frandolig, R. W. Fahien Jun 1957

Mass Transfer In Low Velocity Gas Streams, John E. Frandolig, R. W. Fahien

Ames Laboratory ISC Technical Reports

Experimental studies of the mixing of coaxial streams of carbon dioxide and air at ambient temperature and atmospheric pressure were made at Reynold numbers of 1695, 4510, and 7605.


Semi-Annual Summary Research Report In Physics, Ames Laboratory Staff, F. H. Spedding Mar 1957

Semi-Annual Summary Research Report In Physics, Ames Laboratory Staff, F. H. Spedding

Ames Laboratory ISC Technical Reports

A semi-annual summary research report in physics for the period of July through December of the year 1956.


A Method For Reducing Time Jitter In The Output Of A Single Channel Analyzer, G. W. Eakins, B. J. Loupee, W. A. Rhinehart, G. Schupp Dec 1956

A Method For Reducing Time Jitter In The Output Of A Single Channel Analyzer, G. W. Eakins, B. J. Loupee, W. A. Rhinehart, G. Schupp

Ames Laboratory ISC Technical Reports

An adapter for single channel analyzers has been built which reduces the time jitter in the output of an analyzer by a factor of approximately six. This reduction enables coincidence studies to be conducted using a correspondingly smaller 2τ which results in an approximate sixfold increase in the true to accidental coincidence ratio. In addition the use of a smaller 2τ permits the measurement of significantly shorter half-lives of metastable states than is possible without the use of adapters when only a simple coincidence circuit is utilized.


Chemical Effects Of Photonuclear Reactions In The Propyl Bromides, A. E. Richardson, A. F. Voigt Dec 1956

Chemical Effects Of Photonuclear Reactions In The Propyl Bromides, A. E. Richardson, A. F. Voigt

Ames Laboratory ISC Technical Reports

When nuclear reactions occur in atoms in molecules chemical changes follow as a result of the recoil of the product atoms. The nature of these chemical changes has been studied intensively for a number of systems but in most cases the magnitude of the recoil energy has been about the same. In the present studies use was made of a much greater recoil energy than that normally used. The reaction Br(γ,η)Br* gives a recoil bromine2 atom with an energy of the order 105ev, compared to 102ev for the product of the Br ...


Semi-Annual Summary Research Report In Physics, Ames Laboratory Staff, F. H. Spedding Oct 1956

Semi-Annual Summary Research Report In Physics, Ames Laboratory Staff, F. H. Spedding

Ames Laboratory ISC Technical Reports

A semi-annual report summary research report in physics for the period of January through June of 1956


Measurement Of Magnetic Field Gradients By The Hall Effect, Robert D. Redin, G. C. Danielson Dec 1955

Measurement Of Magnetic Field Gradients By The Hall Effect, Robert D. Redin, G. C. Danielson

Ames Laboratory ISC Technical Reports

A magnetic field gradient measuring device, which uses the Hall effect in germanium, has been constructed. The field sensitive element is a bar of germanium 1 mm by 1 mm by 12 mm with two sets of Hall leads attached 2 mm either side of its center. One hundred cycle alternating current flows in the long direction of the bar. In a magnetic field two 100 cycle Hall voltages are obtained. These voltages, which are proportional to the magnetic field strength at two points of the field 4 mm apart, are subtracted to give an output directly proportional to the ...


The Stress-Strain Characteristics Of Uranium, David A. Mccutchan, Glenn Murphy Dec 1955

The Stress-Strain Characteristics Of Uranium, David A. Mccutchan, Glenn Murphy

Ames Laboratory ISC Technical Reports

Tests were made in reversed loading and in repeated tensile loading on thirteen specimens of rolled, alpha-uranium at room temperature. Constant strain rates ranging from 0.0003 in./in./min. to 0.0060 in./in./min. were employed.


Temperature Coefficient Of Electrical Conductivity In The System Potassium Chloride - Zinc Chloride, R. A. Fleming, R. R. Duke Dec 1955

Temperature Coefficient Of Electrical Conductivity In The System Potassium Chloride - Zinc Chloride, R. A. Fleming, R. R. Duke

Ames Laboratory ISC Technical Reports

The phase diagram of the system KCl-ZnCl2 has been constructed. Values of specific conductivity and density have been determined at eight temperatures in the range 475-650°C. for a series of compositions covering the concentration range. From these data, equivalent conductivities were calculated. The temperature coefficient of conductivity as expressed by the activation energy of ionic migration was calculated at four temperatures for each mixture.


A Possible Method For Beam Extraction From An Alternating Gradient Synchrotron, Loren R. Mcmurray, Daniel J. Zaffarano Nov 1955

A Possible Method For Beam Extraction From An Alternating Gradient Synchrotron, Loren R. Mcmurray, Daniel J. Zaffarano

Ames Laboratory ISC Technical Reports

A mathematical analysis of the effects of perturbations upon the guide field of a circular alternating gradient synchrotron was made to determine the amount and type of perturbation which would make the horizontal motion unstable, but would not affect the vertical motion to the extent that it would become unstable. The purpose of the analysis was to determine if the technique of beam extraction developed by Hammer and Bureau for a conventional synchrotron would apply to an alternating gradient synchrotron.


Multi-Band Electrical Conduction, John Browning Gibson, Joseph M. Keller Aug 1955

Multi-Band Electrical Conduction, John Browning Gibson, Joseph M. Keller

Ames Laboratory ISC Technical Reports

Scattering amplitudes arising from lattice vibrations are calculated for electrons in a transition metal, with special reference to nickel. The potential in the crystal is treated as a deformable potential, with corrections to adjust the zero of potential and to include effects of the redistribution of charge during lattice vibration.


Comparative Yields Of Fe54(Γ, Pn)Mn52 And Fe54(Γ, 2n)Fe52, Raymond M. Henry, Don S. Martin Aug 1955

Comparative Yields Of Fe54(Γ, Pn)Mn52 And Fe54(Γ, 2n)Fe52, Raymond M. Henry, Don S. Martin

Ames Laboratory ISC Technical Reports

The relative rates of formation of four photonuclear reactions produced by 70 Mev X-ray irradiations of iron metal were measured. The reactions investigated were the Fe54( γ,pn)Mn52m, Fe54(γ,pn)Mn52, Fe54(γ,2n)Fe52 and Fe57(γ,p)Mn56. The manganese yields were determined by measuring the radioactive manganese chemically separated from the target material. It was found that the total (γ,pn) yield was about 19 times greater than the (γ,2n) yield. This result is explained in terms of the lmver threshold energy of the (γ,pn ...


Electrical Properties Of Magnesium Silicide And Magnesium Germanide, Charles R. Whitsett, G. C. Danielson Jul 1955

Electrical Properties Of Magnesium Silicide And Magnesium Germanide, Charles R. Whitsett, G. C. Danielson

Ames Laboratory ISC Technical Reports

Single crystals of Mg2Si and Mg2Ge, of high purity, on the order of 1 mm x 1 mm x 1 em in size were obtained, and measurements were made of their electrical resistivities and Hall coefficients in the temperature range 60°K- 1000°K. Both compounds behaved typically as excess impurity semiconductors and exhibited apparent intrinsic conduction above 450°K.


Measurement Of The Ionization Yield Of Low Energy Atomic Particles In Gases, Ralph Lowry, Glenn H. Miller Jun 1955

Measurement Of The Ionization Yield Of Low Energy Atomic Particles In Gases, Ralph Lowry, Glenn H. Miller

Ames Laboratory ISC Technical Reports

The purpose of this investigation was to study the total ionization yield of charged atomic particles in gases for energies in the range of a few to 250 kev. A large cylindrical ionization chamber was used for this study. The charged particles were selected from the kevatron beam by a magnetic and an electrostatic analyzer and entered the chamber by means of a 0.004 inch diameter open window. A differential pumping system permitted pressures up to 10 mm Hg to be maintained in the chamber. The chamber was alternately operated as a proportional counter and an ionization chamber to ...


Secondary Electron Emission Due To Positive Ion Bombardment, John W. Murdock, Glenn H. Miller Jun 1955

Secondary Electron Emission Due To Positive Ion Bombardment, John W. Murdock, Glenn H. Miller

Ames Laboratory ISC Technical Reports

Stray electrons were produced in the Ames Laboratory linear accelerator by the ion beam striking the target and various other parts of the accelerator. This experiment was done to determine if the stray electrons from parts of the accelerator other than the target could be reduced by using construction materials other than brass. Measurements of the number of electrons produced from several materials, however, indicated that there is no particular advantage in using other materials in place of brass.


Beta Spectra Of Some Short-Lived Nuclides, Laurence S. Ring Jr., D. J. Zaffarano Jun 1955

Beta Spectra Of Some Short-Lived Nuclides, Laurence S. Ring Jr., D. J. Zaffarano

Ames Laboratory ISC Technical Reports

The determination of the energy endpoints of the beta radiation spectra from the parent nuclides of 'mirror' pairs was undertaken utilizing an improved scintillation spectrometer as the means of detection. The Iowa State College 67 Mev synchrotron was used to create the short-lived parent nuclei, and a short pneumatic tube was used to transport the samples rapidly to the counting position.


Determination Of The Angular Spread Of The X-Ray Beam From The I. S. C. (70-Mev) Synchrotron, Guveren M. Anderson, D. J. Zaffarano Mar 1955

Determination Of The Angular Spread Of The X-Ray Beam From The I. S. C. (70-Mev) Synchrotron, Guveren M. Anderson, D. J. Zaffarano

Ames Laboratory ISC Technical Reports

The radioactivity produced in copper and carbon strips by irradiation with 66 Mev bremmstrahlung is used to determine the angular spread of the X-ray beam. The beam breadth at half maximum intensity indicated an angular spread of 2.03 +/- 0.03 degrees with copper, and a spread of 2.08 +/- 0.04 degrees with carbon detectors. These results are approximately eight per cent smaller than predicted by Schiff's theory for a target of tungsten, 5 mils thick.


Ratio Of Solid Velocity To Mixture Velocity In Slurry Flow, Richard J. Burian, Glenn Murphy Mar 1955

Ratio Of Solid Velocity To Mixture Velocity In Slurry Flow, Richard J. Burian, Glenn Murphy

Ames Laboratory ISC Technical Reports

The study consisted of two parts, a theoretical analysis of the problem and an experimental investigation under controlled conditions. The theoretical analysis resulted in an equation which expressed the velocity ratio in terms of dimensionless parameters representing the distribution of the particles in the mixture, the slip between the solid particles and the adjacent fluid, and the velocity distribution of the fluid in the conduit.


Preparation, Properties, And Analytical Applications Of Some Substituted Alicyclic Vic-Dioximes, Donald Thomas Hooker, Charles V. Banks Mar 1955

Preparation, Properties, And Analytical Applications Of Some Substituted Alicyclic Vic-Dioximes, Donald Thomas Hooker, Charles V. Banks

Ames Laboratory ISC Technical Reports

The application of organic analytical reagents to the determination of metallic ions has progressed rapidly in the last few decades. Many of these organic compounds have proved to be selective in their action and thereby make possible the determination of one or two ions in the presence of several others.


High Specific Radioactivities Of Osmium From Photonuclear Reactions, R. F. Mitchell, D. S. Martin Jan 1955

High Specific Radioactivities Of Osmium From Photonuclear Reactions, R. F. Mitchell, D. S. Martin

Ames Laboratory ISC Technical Reports

The investigation described in this thesis has included a study of the activities in iridium, osmium, and rhenium which were produced by photonuclear reactions in osmium and iridium. Osmium activities produced by slow neutron bombardment on osmium metal have also been investigated. During the course of these experiments a method of concentrating osmium activities by the Szilard-Chaimers process was discovered and was further developed.