Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

Physics Faculty Research & Creative Works

Discipline
Keyword
Publication Year

Articles 1651 - 1680 of 1959

Full-Text Articles in Physical Sciences and Mathematics

Photoconductivity Parameters In Lithium Niobate, Robert Gerson, J. F. Kirchhoff, L. E. Halliburton, D. A. Bryan Dec 1986

Photoconductivity Parameters In Lithium Niobate, Robert Gerson, J. F. Kirchhoff, L. E. Halliburton, D. A. Bryan

Physics Faculty Research & Creative Works

Measurements on a variety of doped (magnesium and/or iron) and undoped lithium niobate crystals in the oxidized state demonstrate an Arrhenius dependence of dark conductivity on reciprocal temperature between 460 and 590 K. All of the crystals had roughly the same conductivity and activation energy (1.21 eV) over the temperature range, implying that all have about the same free-carrier concentration and mobility. The enhanced photoconductivity of magnesium-doped lithium niobate is attributed to a greatly reduced trapping cross section of Fe3+ for electrons, the smaller cross section being due to a changed substitutional site for Fe3+. The Fe …

Go to article

Two-Step Stabilization Of Autoionizing States, J. Greg Story, Linn D. Van Woerkom, William E. Cooke Nov 1986

Two-Step Stabilization Of Autoionizing States, J. Greg Story, Linn D. Van Woerkom, William E. Cooke

Physics Faculty Research & Creative Works

A two-step process using internal conversion and fluorescence to stabilize the 6P3/211d autoionizing state of barium has been observed. The internal conversion produces very highly excited autoionizing Rydberg states, which then emit fluorescence to produce singly excited, bound states. Inclusion of this process should bring calculations closer to agreement with recent measurements of dielectronic recombination.

Go to article

Experimental Test Of Higher-Order Electron-Capture Processes In Collisions Of Fast Protons With Atomic Hydrogen, Hans G. Vogt, Reinhold S. Schuch, Edson L B Justiniano, Michael Schulz, W. Schwab Nov 1986

Experimental Test Of Higher-Order Electron-Capture Processes In Collisions Of Fast Protons With Atomic Hydrogen, Hans G. Vogt, Reinhold S. Schuch, Edson L B Justiniano, Michael Schulz, W. Schwab

Physics Faculty Research & Creative Works

We present measurements of the angular distribution of fast hydrogen atoms formed by electron capture of 2.8- and 5.0-MeV protons in atomic hydrogen. In the angular region of the Thomas peak (0.47 mrad) the experimental results obtained with this pure three-body collision system are in reasonable agreement with a strong-potential Born calculation and the impulse approximation, but not with other higher-order theories.

Go to article

Measurement Of The Lifetime Of The Metastable 5d3/226d3/2, J=0 Autoionizing State Of Barium, Linn D. Van Woerkom, J. Greg Story, William E. Cooke Oct 1986

Measurement Of The Lifetime Of The Metastable 5d3/226d3/2, J=0 Autoionizing State Of Barium, Linn D. Van Woerkom, J. Greg Story, William E. Cooke

Physics Faculty Research & Creative Works

We report a measurement of the lifetime of the metastable 5d3/226d3/2, J=0 autoionizing state of barium. We have determined the lifetime to be 190(10) ns.

Go to article

Application Of A Scaled Homogeneous Nucleation-Rate Formalism To Experimental Data At T≪TC, Barbara N. Hale Jun 1986

Application Of A Scaled Homogeneous Nucleation-Rate Formalism To Experimental Data At T≪TC, Barbara N. Hale

Physics Faculty Research & Creative Works

It is pointed out that for temperatures T<0.5Tc, where Tc is the critical temperature, the classical steady-state nucleation-rate formalism of Becker and Doring predicts an approximate critical supersaturation ratio Scr (for the onset of nucleation) given by lnScr/Ω3/2~0.53(Tc/T-1)3/2. Ω is a material-dependent quantity approximately equal to the excess surface entropy per molecule. For most substances Ω ~ 2.0 and for associated liquids Ω ~ 1.5.The experimental data (for nucleation from vapor to liquid) from diffusion chamber and nozzle beam studies are found to be consistent with the above …

Go to article

Lna: A New Cw Nd Laser Tunable Around 1.05 And 1.08 Μm, Laird D. Schearer, Michele Leduc, Daniel Vivien, Anne Marie Lejus, Jeanine Thery Jan 1986

Lna: A New Cw Nd Laser Tunable Around 1.05 And 1.08 Μm, Laird D. Schearer, Michele Leduc, Daniel Vivien, Anne Marie Lejus, Jeanine Thery

Physics Faculty Research & Creative Works

We have investigated the CW laser properties of the lanthamide hexa-aluminate La0.9Nd0.1MgAl11O19 at room temperature. When a I cm long crystal is pumped by an Ar+ laser (514 nm) or a Kr+ laser (752 nm), CW emission is obtained with slope efficiencies of 10 and 26 percent, respectively. A four-plate Lyot filter in the cavity forces the LNA crystal to oscillate in either of the two major bands centered at 10 820 A (tuning range 80 A) and 10 545 A (tuning range 35 Å). Copyright © 1986 by The Institute of Electrical and Electronics Engineers, Inc.

Go to article

The Spin‐1 Anisotropic Heisenberg Ferromagnet With Biquadratic Exchange, Harry A. Brown Jan 1986

The Spin‐1 Anisotropic Heisenberg Ferromagnet With Biquadratic Exchange, Harry A. Brown

Physics Faculty Research & Creative Works

No abstract provided.

Go to article

Comments On The Raindrop Problem, I. Adawi Jan 1986

Comments On The Raindrop Problem, I. Adawi

Physics Faculty Research & Creative Works

No abstract provided.

Go to article

Resonant Transfer And Excitation: Dependence On Projectile Charge State And Target-Electron Momentum Distribution, J. A. Tanis, E. M. Bernstein, M. W. Clark, W. G. Graham, Robert H. Mcfarland, T. J. Morgan, J. R. Mowat, D. W. Mueller, A. Müller, M. P. Stockli, K. H. Berkner, P. Gohil, R. J. Mcdonald, A. S. Schlachter, J. W. Stearns Jan 1986

Resonant Transfer And Excitation: Dependence On Projectile Charge State And Target-Electron Momentum Distribution, J. A. Tanis, E. M. Bernstein, M. W. Clark, W. G. Graham, Robert H. Mcfarland, T. J. Morgan, J. R. Mowat, D. W. Mueller, A. Müller, M. P. Stockli, K. H. Berkner, P. Gohil, R. J. Mcdonald, A. S. Schlachter, J. W. Stearns

Physics Faculty Research & Creative Works

Resonant transfer and excitation (RTE) involving simultaneous electron capture and projectile K-shell excitation has been measured for calcium ions in charge states ranging from neon like to hydrogen like incident on molecular hydrogen over an energy range 100-370 MeV. The results establish a projectile charge-state dependence for RTE and provide a detailed test of theoretical calculations. The effect of the target-electron momentum distribution on the RTE process is demonstrated by comparing with previous results for calcium ions incident on helium. © 1986 The American Physical Society.

Go to article

Electron Capture And Loss For 2.5-200-Mev 16s13++He Collisions, M. W. Clark, E. M. Bernstein, J. A. Tanis, W. G. Graham, Robert H. Mcfarland, T. J. Morgan, B. M. Johnson, K. W. Jones, M. Meron Jan 1986

Electron Capture And Loss For 2.5-200-Mev 16s13++He Collisions, M. W. Clark, E. M. Bernstein, J. A. Tanis, W. G. Graham, Robert H. Mcfarland, T. J. Morgan, B. M. Johnson, K. W. Jones, M. Meron

Physics Faculty Research & Creative Works

Electron capture and loss cross sections have been measured for highly charged (q=13+) sulfur ions with energies 2.5-200 MeV colliding with helium. Electron capture varies by nearly six orders of magnitude over the energy range investigated, while electron loss varies by only about a factor of 2. The capture cross sections are in reasonable agreement with classical and empirical scaling rules, while the loss cross sections agree well with the plane-wave Born approximation. © 1986 The American Physical Society.

Go to article

Structure In The Energy Dependence Of High-Energy Electron-Capture Cross Sections, W. G. Graham, E. M. Bernstein, M. W. Clark, J. A. Tanis, K. H. Berkner, P. Gohil, R. J. Mcdonald, A. S. Schlachter, J. W. Stearns, Robert H. Mcfarland, T. J. Morgan, A. M̈Ller Jan 1986

Structure In The Energy Dependence Of High-Energy Electron-Capture Cross Sections, W. G. Graham, E. M. Bernstein, M. W. Clark, J. A. Tanis, K. H. Berkner, P. Gohil, R. J. Mcdonald, A. S. Schlachter, J. W. Stearns, Robert H. Mcfarland, T. J. Morgan, A. M̈Ller

Physics Faculty Research & Creative Works

Previous experimental and theoretical work has found electron capture to be a monotonically decreasing function of energy in fast ion-atom collisions. We report here the experimental observation of nonmonotonic behavior of the electron-capture cross sections in fast collisions of calcium ions, in charge states 16+ to 19+, with molecular hydrogen, in the energy range 97368 MeV. The structure observed in the measured cross sections is attributed to the contribution of resonant transfer and excitation to electron capture. © 1986 The American Physical Society.

Go to article

V/2 Electrons In H++H Ionizing Collisions, Ronald E. Olson Jan 1986

V/2 Electrons In H++H Ionizing Collisions, Ronald E. Olson

Physics Faculty Research & Creative Works

Classical-trajectory Monte Carlo calculations are used to determine the velocity and angular dependence of the electron ionized in the H++HH++H++e- collision. The energy range studied is 40200 keV. At energies E60 keV, ionized electrons with velocities that are near one-half (v/2) the relative velocity v of the collision dominate the electron spectra. At higher energies the maximum position of the ionized electrons shifts and is found centered about the target nucleus. © 1986 The American Physical Society.

Go to article

Resonant Charge Transfer In Symmetric Alkali-Ion Alkali-Atom Collisions, F. K. Men, M. Kimura, Ronald E. Olson Jan 1986

Resonant Charge Transfer In Symmetric Alkali-Ion Alkali-Atom Collisions, F. K. Men, M. Kimura, Ronald E. Olson

Physics Faculty Research & Creative Works

Resonant charge transfer in alkali-ion alkali-atom collisions is investigated by using the molecular-orbital expansion method incorporating the use of electron translation factors. Molecular wave functions and eigen energies are obtained by the pseudopotential method. Molecular properties, Re, De, and e, obtained in the present calculation are in good accord with other recent theoretical results, as well as spectroscopic measurements. Three-state close-coupling calculations reproduce the positions of the maxima and minima in the oscillatory structure seen experimentally in the resonant-charge-transfer cross sections for the Li2 + and Cs2 + systems. The magnitude of the total cross sections and their velocity dependence …

Go to article

Energy Transfer Collisions Between Vibrationally Excited Molecular Nitrogen And Atoms, Laird D. Schearer Jan 1986

Energy Transfer Collisions Between Vibrationally Excited Molecular Nitrogen And Atoms, Laird D. Schearer

Physics Faculty Research & Creative Works

Chemiluminescent reactions between metastable states of molecular nitrogen and atoms are used to determine the vibrational temperatures of these Non radiating molecular systems. The excitation rates of Na, Mg, Cd, and Zn are used to obtain the vibrational temperature of N2(X 1Σ) and N2(A 3Σ) states in a fast-flowing nitrogen afterglow. The exponential dependence of the intensities of the emission from atoms excited by the energy transfer collisions on the energy of the level yields vibrational temperatures on the order of 3100 K. We also report the presence of apparent strong selection rules on the total spin of the system …

Go to article

Erratum: Dipole Moment And Potential Energy Functions Of The X ¹∑+ And A1∑+ States Of Nah. (The Journal Of Chemical Physics (1984) 80 (356)), W. T. Zemke, Ronald E. Olson, K. K. Verma, W. C. Stwalley, B. Liu Jan 1986

Erratum: Dipole Moment And Potential Energy Functions Of The X ¹∑+ And A1∑+ States Of Nah. (The Journal Of Chemical Physics (1984) 80 (356)), W. T. Zemke, Ronald E. Olson, K. K. Verma, W. C. Stwalley, B. Liu

Physics Faculty Research & Creative Works

No abstract provided.

Go to article

The Three‐Spin Box Product Interaction, Harry A. Brown Jan 1986

The Three‐Spin Box Product Interaction, Harry A. Brown

Physics Faculty Research & Creative Works

The three‐spin interaction in the form of a box product, σ1 x σ2 · σ3, is investigated including additional interaction terms in the Hamiltonian in the forms \document class{article}\page style{empty}\begin{document}$ \sum\limits_i {\sigma _{iz},} \sum\limits_{ij} {\sigma _{iz} \sigma _{jz}} $\end{document}, and πiσiz. With the relative strengths considered as parameters, the thermodynamic properties are evaluated as a function of temperature and show considerable variety. Both second‐ and first‐order phase transitions are found. Copyright © 1986 WILEY‐VCH Verlag GmbH & Co. KGaA

Go to article

Tuning Characteristics And New Laser Lines In An Nd:Yap Cw Laser, Laird D. Schearer, Michele Leduc Jan 1986

Tuning Characteristics And New Laser Lines In An Nd:Yap Cw Laser, Laird D. Schearer, Michele Leduc

Physics Faculty Research & Creative Works

We have investigated the CW laser properties of Nd-doped yttrium-aluminum-perovskite (YAP) in a Kr are-lamp, pumped cavity, Seven laser transitions within the 4F3/2-4I11/2 multiplet have been observed. A simple Lyot filter is used to select the particular transitions. The tuning characteristics of the transitions at 1.0745 and 1.0845 μm were also obtained with the addition of a thin, uncoated etalon within the cavity. Tuning widths of 32 and 23 Å, respectively, were obtained. Copyright © 1986 IEEE

Go to article

General Features Of The Aerosol Observed In The Guinean Savannah At The Level Of The Itcz Influence Of The Drought, F. Désalmand, R. Serpolay, Josef Podzimek Jan 1986

General Features Of The Aerosol Observed In The Guinean Savannah At The Level Of The Itcz Influence Of The Drought, F. Désalmand, R. Serpolay, Josef Podzimek

Physics Faculty Research & Creative Works

The stagnation and mixing of various air masses at the level of the ITCZ in the dry season, together with the absence of rain, favor, in the Guinean savannah, the formation of a well-aged and homogeneous aerosol made up of very active mixed nuclei. When the drought increases, the aerosol always remains an aged one, i.e. absence of particles with radius r < 0.02 μm, no nucleation mode. However, different properties show a younger and less homogeneous aerosol, i.e. very high counts in all the categories of particles (the concentration of nuclei activated at the supersaturation S {reversed tilde equals} 0.32% reaches 9960 cm-3), poor correlations between the concentrations of various groups of particles and no fog. When the fires are frequent and spread all over the savannah, a permanent addition of new particles to the local background aerosol (due to a complicated circulation) prevents the ageing of the aerosol that is observed during the usual drought with a moderate extension of bushfires. © 1986.

Go to article

Multiple-Electron Capture And Ionization In Collisions Of Highly Stripped Ions With Ar Atoms, A. M̈Ller, B. Schuch, W. Groh, E. Salzborn, H. F. Beyer, P. H. Mokler, Ronald E. Olson Jan 1986

Multiple-Electron Capture And Ionization In Collisions Of Highly Stripped Ions With Ar Atoms, A. M̈Ller, B. Schuch, W. Groh, E. Salzborn, H. F. Beyer, P. H. Mokler, Ronald E. Olson

Physics Faculty Research & Creative Works

Multiple-vacancy production in Ar atoms by 1.4-MeV/u highly stripped ion impact is studied. From a recoil-ionprojectile-ion coincidence experiment charge-state distributions of Ar ions were obtained distinguishing between pure ionization and capture of up to three electrons by N6+,7+, Fe12+,15+,20+,21+, Kr18+, Gd37+, and U30+,36+,41+,44+,4 8+ ions. With increasing projectile charge state the relative abundances of multiply charged recoil ions increase. However, for high-charge-state projectiles, the relative fractions of recoil ions for concomitant electron capture and ionization are found to be independent of projectile charge or species. To interpret the data, classical trajectory Monte Carlo calculations have been made assuming the applicability …

Go to article

Ionization Of H And He+ By Electrons And Positrons Colliding At Near-Threshold Energies, A. E. Wetmore, Ronald E. Olson Jan 1986

Ionization Of H And He+ By Electrons And Positrons Colliding At Near-Threshold Energies, A. E. Wetmore, Ronald E. Olson

Physics Faculty Research & Creative Works

Ionization cross sections for the four combinations of electrons and positrons on H and He+ have been calculated at energies near the threshold for ionization using the classical trajectory Monte Carlo method. In addition, charge-exchange (positronium formation) cross sections have been calculated for the positron-impact collisions. The ionization cross sections compare well with the predictions of the Wannier and Klar models and experimental observations. Our results indicate that the Wannier-type threshold behavior may extend to higher energies than was previously thought. In addition, we have calculated two of the collision parameters, the angle and the relative separation between the escaping …

Go to article

Investigation Of The Appropriateness Of Sensitized Luminescence To Determine Exciton Motion Parameters In Pure Molecular Crystals, Vasudev M. Kenkre, Paul Ernest Parris, Dankward B. Schmid Oct 1985

Investigation Of The Appropriateness Of Sensitized Luminescence To Determine Exciton Motion Parameters In Pure Molecular Crystals, Vasudev M. Kenkre, Paul Ernest Parris, Dankward B. Schmid

Physics Faculty Research & Creative Works

A wealth of experimental data has been collected over the years regarding the sensitized luminescence of molecular crystals. Indeed, such observations have played a primary role in attempts to characterize the dynamical aspects of exciton transport in these materials. Nonetheless, as has been noted previously, serious questions of interpretation remain concerning the relationship between primary experimental observables and microscopic parameters which govern exciton transport and capture. In the past these questions have led to an uncertainty, not always acknowledged, in the values of exciton diffusion constants reported in the literature. On the other hand, careful analysis of some recent experiments …

Go to article

Electron Production In Proton Collisions: Total Cross Sections, M. Eugene Rudd, Yongki Kim, Don H. Madison, Jean W. Gallagher Oct 1985

Electron Production In Proton Collisions: Total Cross Sections, M. Eugene Rudd, Yongki Kim, Don H. Madison, Jean W. Gallagher

Physics Faculty Research & Creative Works

Existing data on the ionization of neutral atoms and molecules by proton impact are reviewed, and electron production cross-section data are collected. The three major experimental methods are discussed and possible sources of error identified. Some theoretical cross sections are discussed, and well-established methods of relating them to measured cross sections are reviewed. A mathematical equation is fitted to the weighted experimental data for each target, and these fits are adjusted to be consistent with appropriate theoretical calculations and with electron impact and photoionization data. Recommended values of total cross sections for proton-impact ionization are given.

Go to article

Time-Dependent Magnetic Structures Of The Superconducting Mixed Ternary System Ho(Rh₁₋ₓirₓ)₄B₄, Steven E. Lambert, M. Brian Maple, Oran Allan Pringle, Herbert A. Mook Sep 1985

Time-Dependent Magnetic Structures Of The Superconducting Mixed Ternary System Ho(Rh₁₋ₓirₓ)₄B₄, Steven E. Lambert, M. Brian Maple, Oran Allan Pringle, Herbert A. Mook

Physics Faculty Research & Creative Works

Magnetic structures have been determined by netron diffraction for several compositions in the superconducting mixed ternary system Ho(Rh1-xIrx)4B4. Two features previously reported to occur in the heat capacity for some compositions are shown to correspond to successive magnetic transitions. For x=0.30 and 0.45, neutron diffraction peaks for the lowest temperature structure develop over a timescale of many hours. The results are discussed in terms of magnetic frustration.

Go to article

Angular Differential Cross Sections For The Excitation Of 1¹S Helium To The 2¹S And 2¹P States By 25- To 100-Kev-Proton Impact, Thomas J. Kvale, Denver G. Seely, D. M. Blankenship, E. Redd, Timothy Gay, Mineo Kimura, Eduard P. Rille, Jerry Peacher, John T. Park Sep 1985

Angular Differential Cross Sections For The Excitation Of 1¹S Helium To The 2¹S And 2¹P States By 25- To 100-Kev-Proton Impact, Thomas J. Kvale, Denver G. Seely, D. M. Blankenship, E. Redd, Timothy Gay, Mineo Kimura, Eduard P. Rille, Jerry Peacher, John T. Park

Physics Faculty Research & Creative Works

Angular differential cross sections for the proton-impact excitation of ground-state helium (11S) to the 21S and 21P states have been measured for the first time in the energy range 25 to 100 keV with use of the energy-loss technique. The data indicate that, for very small scattering angles, at 25 keV the 21S differential cross section is greater than the 21P differential cross section. For impact energies greater than 50 keV, the 21P differential cross section clearly dominates over the 21S cross section in the very …

Go to article

Low Temperature Tunneling Dynamics In Condensed Media, Paul Ernest Parris, Robert J. Silbey Aug 1985

Low Temperature Tunneling Dynamics In Condensed Media, Paul Ernest Parris, Robert J. Silbey

Physics Faculty Research & Creative Works

There has been considerable interest recently in the low temperature dynamics of condensed phase tunneling phenomena. In this paper we consider the interplay between quasiparticle transport and vibrational relaxation; the former taking place via tunneling in a double well potential, and the latter occurring due to interactions of the tunneling system with a harmonic bath. Taking the system-bath interactions to be linear in the bath coordinates, and explicitly allowing for a vibrationally excited well, we present a unified treatment of the weak and strong coupling regimes and obtain reduced equations of motion for the tunneling particle position operator. Solutions are …

Go to article

Small-Angle Neutron Scattering Of (Er₀.₈Ho₀.₂)Rh₄B₄, Oran Allan Pringle, Herbert A. Mook, M. Brian Maple Apr 1985

Small-Angle Neutron Scattering Of (Er₀.₈Ho₀.₂)Rh₄B₄, Oran Allan Pringle, Herbert A. Mook, M. Brian Maple

Physics Faculty Research & Creative Works

The (Er1-xHox)Rh4B4 pseudoternary alloy system has a minimum in the phase boundary between the superconducting and ferromagnetic phases near x=0.3. This minimum has been identified as due to the competing magnetic anisotropies of Er and Ho. It has also been suggested that there could be a Lifschitz point near the minimum. Using the 30-m SANS camera at the National Center for Small-Angle Scattering Research at ORNL, we have observed a peak in the SANS pattern for (Er 0.8Ho0.2)Rh4B4 at Q=0.065 Å-1. This peak appears for …

Go to article

Laser-Assisted Charge-Transfer Collisions: K++Na, Y. P. Hsu, M. Kimura, Ronald E. Olson Jan 1985

Laser-Assisted Charge-Transfer Collisions: K++Na, Y. P. Hsu, M. Kimura, Ronald E. Olson

Physics Faculty Research & Creative Works

A theory has been formulated to characterize charge-transfer collisions in the presence of an external laser field. The molecular-state-expansion method is used to describe the scattering process within the impact-parameter formalism. Electron translation factors are included in the molecular-state expansion so that the scattering wave function satisfies the correct boundary conditions. The theory is applied to the process K++NaK+Na+. In addition, we have made a detailed analysis of laser-assisted charge transfer for low-energy collisions. In this case, a Landau-Zener formula can be derived which shows that the cross section increases with decreasing incident energy. In general the laser coupling is …

Go to article

Faraday's Law Demonstration, Richard Sankovich Jan 1985

Faraday's Law Demonstration, Richard Sankovich

Physics Faculty Research & Creative Works

No abstract provided.

Go to article

Neutron-Diffraction Study Of The Magnetic Ordering In Ni(Ch₂Co₂Nh₂)₂ 2h₂O, Akifumi Onodera, Yorihiko Tsunoda, Nobuhiko Kunitomi, Oran Allan Pringle, Robert M. Nicklow, Ralph M. Moon Jan 1985

Neutron-Diffraction Study Of The Magnetic Ordering In Ni(Ch₂Co₂Nh₂)₂ 2h₂O, Akifumi Onodera, Yorihiko Tsunoda, Nobuhiko Kunitomi, Oran Allan Pringle, Robert M. Nicklow, Ralph M. Moon

Physics Faculty Research & Creative Works

The magnetic structure of Ni(CH2CO2NH2)2 2 H2O has been determined by the analysis of neutron-diffraction data from powder and single-crystal samples. Ni(CH2CO2NH2)2 2 H2O orders at a Néel temperature of 0.88 K. The magnetic structure consists of antiferromagnetically coupled layers having a canted ferromagnetic ordering within layers, with a moment of (2.33 ± 0.14)μB per Ni2+ ion. The magnetic unit cell is composed of two crystallographic unit cells, and contains four nickel atoms. The moment direction is not simply related …

Go to article

Computerized Scanning Auger Microprobe, T. J. Sommerer, Edward Boyd Hale Jan 1985

Computerized Scanning Auger Microprobe, T. J. Sommerer, Edward Boyd Hale

Physics Faculty Research & Creative Works

An Auger spectrometer has been automated using a microcomputer. Fundamental considerations in the design and choice of the computerized system are presented and should be of general interest. The spectrometer was a Physical Electronics Ind. model 545 scanning Auger microprobe. The microcomputer chosen was a Southwest Technical Products 6809 computer system. Hardware details are discussed with emphasis on the four computer-spectrometer interface boards. These boards are (1) Auger energy control board, which sets the Auger detection energy with its 16 bit digital-to-analog converter (DAC); (2) read Auger signal board, which reads the Auger signal intensity with its 12 bit analog-to-digital …

Go to article

First Prev Next Last