bluuebunny/crossref_metadata_2025 huggingface dataset:
Electron–Phonon Interaction in Simple Metals: Beyond the Diffraction Model
Authors: Perdew J. P. , Vosko S. H. , Moore R. A.
Published: October 2017

The exact solution to the self-consistent field screening problem presented in a previous paper (Moore et al.), reduces in the weak pseudopotential limit to the diffraction model for the electron–phonon matrix element, and in particular to Animalu's expression for the screening of a nonlocal pseudopotential. Systematic corrections to the diffraction model, including local field effects, are presented for a pseudopotential of moderate strength; these corrections are particularly simple when the pseudopotential is local. Local pseudopotential calculations of the anisotropic electron–phonon form factors indicate that corrections to the diffraction model are small in sodium but substantial in lithium.
Deuteron Polarization in e–d Scattering
Authors: Brady T. J. , Tomusiak E. L. , Levinger J. S.
Published: October 2017

The tensor polarization of the deuteron in elastic electron–deuteron scattering depends on the ratio of deuteron quadrupole and monopole form factors. Measurements at [Formula: see text] are sensitive to the deuteron percentage D state; while measurements at [Formula: see text] are sensitive to a diffraction minimum in the monopole form factor.
Proton Spin-Lattice Relaxation Study of Order Fluctuations Above The Smectic A-Isotropic Transition in a Liquid Crystal
Authors: Dong Ronald Y. , Wiszniewska M. , Tomchuk E. , Bock E.
Published: October 2017

The proton spin-lattice relaxation time T1 in the isotropic phase of the smectic A liquid crystal diethylazoxybenzoate was measured at several Larmor frequencies in the range from 5 to 60 MHz. The frequency dependent T1 at 25 °C above the smectic A-isotropic phase transition (Tc) is attributed to molecular diffusion. The critical temperature dependent (T1)cf, the spin-lattice relaxation time due to critical order fluctuations, at 5 MHz can be understood by assuming that the effective viscosity has a critical temperature behavior just above Tc. It was deduced that the effective viscosity diverges as ξ2 in the mean field approximation, where ξ is a coherence length describing the short range order.
Electron–Hole Droplets in Semiconducting and Metallic Silicon
Authors: Halliwell R. E. , Parsons R. R.
Published: October 2017

The photoluminescence spectrum of phosphorus-doped silicon has been studied as a function of impurity concentration 9.0 × 1015 cm−3 ≤ ND ≤ 4.3 × 1019 cm−3 and temperature 1.9 K ≤ T ≤ 145 K. The spectra at low temperature [Formula: see text] are interpreted in terms of a condensed phase of carriers (electron–hole droplet) over the entire range of concentrations studied.
CGL Invariants and the Moments of the Boltzmann–Vlasov Equation
Authors: Fridman M.
Published: October 2017

The transport laws of the noncollisional systems must be obtained from the Boltzmann–Vlasov equation. The most simple cases are the CGL invariants along the magnetic field. The essential problem is to determine the criteria necessary to close the moments system. The lower order in the gyration radius expansion gives the perpendicular contribution to the heat flux. After expansion with the supersonic conditions, the parallel contribution is obtained, and also the second term of the expansions in which the first term is the "invariant." The numerical value of the heat flux can be considered in good agreement with the solar wind parameters, and the corrections to the invariants are found to agree with previous results (kinetical and 20-moments Grad approximation).
La méthode de Grad des 20 moments et les invariants CGL. Application au vent solaire
Authors: Fridman M.
Published: October 2017

The experimental data of the quiet solar wind appear to be the result of perturbations over the simple expansion of the solar plasma. The distribution function obtained by the 20 moments Grad method, but simplified by the parallel flux has been proposed by Whang to interpret the experimental data of Hundhausen. This distribution has been used to close the moments system of a simple expansion which gives the perpendicular and parallel contribution to the parallel heat flux. The terms in the development which immediately follow the CGL invariants are obtained. The numerical value of the heat flux agrees with Whang's and Hundhausen's, and the corrections to the invariants are in agreement with the kinetic results of Hollweg and HD of Fridman if the closure of the moments system is made by the highly supersonic flux condition.
Negative Parity Levels in 30Si
Authors: Greene M. Wayne , Grawe H. H. , Kuehner J. A.
Published: October 2017

A polarization direction correlation measurement of γ rays from the 7.044 MeV level in 30Si results in Jπ = 5− for this level and implies a Jπ = 4− assignment for the level at 6.503 MeV. A particle gamma ray coincidence measurement establishes a new decay branch (15 ± 4%) for the 6.503 MeV level to the 5.485 MeV Jπ = 3− level. The Doppler shift attenuation method was used to measure the mean lifetime of the 7.044 MeV level as [Formula: see text]. A simple shell model structure for the low lying negative parity states is presented and shown to be consistent with experimental measurements.
Molecular Model Calculations of Pair–Modes in Alkali Halides
Authors: Ward R. W. , Clayman B. P.
Published: October 2017

The molecular model, developed by Jaswal for [100] aligned impurity pairs, has been extended to account for [110] aligned pairs and used to study U center (H−H− and D−D−) pairs in KCl and (Cl−Cl− and Na+Na+)-induced pair–modes in the gap of KI. In this model the impurity ions in the pair and their nearest neighbors are allowed to vibrate while the rest of the lattice is held fixed. For [110] and [100] aligned pairs, this gives 12- and 17-ion molecules respectively. The potential energy is treated in the rigid ion approximation with short range forces between the nearest neighbors only. After the single relevant parameter of the model, the nearest neighbor force constant, is fitted to the U center local mode frequency, the model can account for the experimentally observed frequencies and polarizations of the three U center pairs in KCl. Similarly, after fitting to the single ion Cl− gap mode at 77 cm−1 in KI, the model predicts 3 infrared active pair–modes whose frequencies are in close agreement with experiment. In KI:Na+, where no single ion resonance has been observed, the calculated results suggest that the absorption lines are due to [110] aligned Na+ ions, with a large softening of the short range force constants occurring around the defect. The KI:Br− and NaCl:F− systems are also considered.
Some Thermodynamic Properties of Pure and Impure Nitrogen
Authors: Ancsin J.
Published: October 2017

Boiling points, freezing points, and vapor pressures (from 56 K to the normal boiling point) for pure and various doped N2 samples have been measured. The normal boiling points for N2 and N2 doped with 100 v.p.p.m. of O2, Ar, Kr, and CO impurities were found to be 77.3439 K, 77.3458 K, 77.3452 K, 77.3454 K, and 77.3444 K respectively. The triple points of the same samples are 63.14635 K, 63.1445 K, 63.14575 K, 63.1487 K, and 63.14675 K respectively.

The values obtained for the heats of sublimation, vaporization, and fusion at the triple point of pure N2 were 6773.8, 6049.6, and 724.3 J/mole respectively and the above impurities changed these quantities by the amounts given in Tables 5 and 6.
Generalized Phase Space Formulation of the Hamiltonian Dynamics
Authors: Razavy M. , Kennedy Frederick James
Published: October 2017

In an n dimensional phase space, the generator of the time translation can be written in terms of a Hamiltonian and a set of Poisson brackets for the phase space variables. When the velocity vector in this phase space is divergenceless, then the equations of motion reduce to those obtained by Nambu. The extension of the Hamiltonian dynamics to the phase space of arbitrary dimensions enables one to find a generalized Hamiltonian function for equations of motion involving time derivatives of any order (even or odd) of the coordinates. The problem of quantization of Nambu's generalized dynamics is studied, and it is shown that in certain cases, for a system moving under a set of constraints, it is possible to replace the Hamiltonian operator by an infinite number of generators of time translation functions. Some examples from classical dynamics and quantum mechanics are given to show the range of applicability of the generalized phase space formulation.
A New Electromagnetic Mode in Cu
Authors: Carolan J. F.
Published: October 2017

For a thin slab of Cu with a static magnetic field applied normal to the slab and approximately along the [110], we have studied the circularly polarized transmission of electromagnetic waves in the 1.0 MHz range. We find that the previously reported oscillations propagating in the Doppler shifted cyclotron resonance (DSCR) absorption region have a polarization sense opposite to that of the helicon and we interpret these as a mode associated with the DSCR. We have computed the dispersion using an approximate copper Fermi surface and find agreement with the experimental dispersion and attenuation. The mode is similar in origin to that predicted for a model Fermi surface with electrons which drift along the field with a constant displacement per cyclotron period.
Temperature Dependence of Positron Vacancy Trapping
Authors: Bergersen Birger , Taylor David W.
Published: October 2017

A critical discussion is given of the several conflicting models that have been proposed for the temperature dependence of positron trapping by vacancies in metals. It is found that models utilizing the concept of a velocity independent trapping radius do not give a consistent description. If the trapping potential is not too strong the model most appropriate to the problem is one proposed by Hodges in which plane wave perturbation theory and the golden rule is used. When particle–hole pairs take up the excess energy and when the trap is deep compared to kBT this gives a trapping rate per unit vacancy concentration which is essentially independent of temperature. The condition on the strength of the potential is found to be well satisfied assuming a hydrogenic wave function for the trapped state with a Bohr radius determined from the energy of the state. Even if the trapping potential should be too strong for the golden rule to be completely valid no important temperature dependence of the trapping rate is expected.
Disorientation of 3He 1D States in 3He–3He Collisions
Authors: Pinard M. , Linde J. Van Der
Published: October 2017

Cross sections have been measured for the disorientation of the 3 1D, 4 1D, and 5 1D states of 3He in collisions with the ground state atoms. Oriented n1D state atoms are produced by exciting in a discharge 3He atoms whose nuclei have been oriented by optical pumping. The role of hyperfine coupling is investigated and the theoretical treatment of the effect of collisions on the orientation of the excited atom, which does not require instantaneous recoupling of the nuclear spin I and the electronic angular momentum J after each collision, is presented.
The Effect of Hydrostatic Pressure on the Fermi Surfaces of Copper, Silver, and Gold. II. High Precision Studies
Authors: Templeton I. M.
Published: October 2017

New high precision measurements of the effect of hydrostatic pressure on six extremal cross sections of the Fermi surfaces of copper, silver, and gold are reported. The fluid-helium, de Haas – van Alphen phase-shift technique was used, and the results were of sufficient precision that valid Fourier expansion and phase-shift fits to the departures from linear scaling could be made. Contour stereograms show that in all cases the existing distortions from sphericity of the Fermi surface are increased. The results for changes of neck cross section are in agreement with previous figures for copper and gold, showing total rates of change 4.2 and 5.6 times scaling respectively, but the neck in silver is found to increase at about 10.6 times the scaling rate, in disagreement with an earlier figure of 7.3 times.
Transfer of Electronic Excitation between the 72P1/2 and 72P3/2 States of Cesium Induced by Collisions with Cesium Atoms
Authors: Pace Paul W. , Atkinson J. B.
Published: October 2017

The method of sensitized fluorescence has been employed to investigate the [Formula: see text] excitation transfer processes in cesium induced in collisions with ground state cesium atoms. The cesium vapor density was kept sufficiently low to enable the cross sections for the mixing process to be determined under single collision conditions and to ensure that radiation trapping and quenching were negligible. A nitrogen laser pumped dye laser was used to excite the cesium atoms to each of the 72P levels in turn and measurements of the relative intensities of fluorescence yielded the following cross sections:

[Formula: see text]

These results are consistent with the empirical relationship between the magnitude of the cross sections and the fine structure splitting that has previously been determined for the alkalis.
Application of the Green Function Method to the XY Model in a Magnetic Field
Authors: Austen D. J.
Published: October 2017

This paper exhibits a simple, approximate Green function solution for the XY model of ferromagnetism in three dimensions from which we obtain the critical temperature, magnetization, internal energy, free energy, and entropy as a function of a magnetic field in the z direction. Comparison with Padé analysis of known high temperature series indicates an accuracy for TC in zero field to within 2% on all three cubic lattices and improved accuracy for nonzero fields. Solutions are obtained only for T ≥ TC.
Lifetime of the 5p2P1/2 Level of Ionized Strontium
Authors: Kelly F. M. , Koh T. K. , Mathur M. S.
Published: October 2017

The lifetime of the 5p2P1/2 level of Sr+ has been measured using the Hanle effect, or zero field level crossing technique, with optical excitation from the ground state of the ion. Circularly polarized light is used in the excitation and analysis. The ions are produced in a discharge at the mouth of the furnace used to produce a beam of strontium atoms. No foreign gas is used to carry the discharge. The oscillator strength of the 4215 Å, 5s2S1/2–5p2P1/2 transition is discussed.
State Functions for Many Electron Atoms: Eigenfunctions of L2 and S2 for One Open Shell Configurations
Authors: Karwowski Jacek , Fraga Serafin
Published: October 2017

The construction of eigenfunctions of L2 and S2 using a new formalism, that represents an alternative to the Racah genealogical scheme, is discussed. The corresponding functions have been tabulated for all the states arising from pN, dN, and fN configurations; this tabulation, not presented here because of space restrictions, is available as indicated in the text.
Study of Levels in 55Mn by Coulomb Excitation
Authors: Kulkarni R. G. , Nainan T. D.
Published: October 2017

The first five excited levels in 55Mn were studied by means of Coulomb excitation by alpha particles varying in energy from 5–7 MeV. The Coulomb character of these levels in 55Mn was confirmed by comparing thick target yields to the theoretical predictions. The reduced E2 transition probabilities B(E2)↑ were obtained for these five levels from thick target yields. The gamma–gamma coincidences were measured to identify cascade gamma transitions and branching ratios. The experimentally found B(E2)↑ values were compared with the theoretical calculations of two different authors.
Quantum Theory of Spectral Modulation
Authors: Zardecki Andrzej , Delisle Claude
Published: October 2017

Recent experiments of Delisle and Brochu, in which spectral modulation at a large path difference was observed, are analyzed in quantum mechanical terms. Starting with a stationary density operator for thermal light, a two beam superposition such as taking place in a Michelson interferometer, is investigated. It is shown that a simple interference law holds separately for each mode of radiation. Consequently, a coherent superposition of light should be observed for a time delay arbitrarily large compared to the coherence time. The latter determines merely the range of intensity modulation. Analysis of the Michelson interferometer accounting for the energy returned to the source is also presented.
Representation of the Coherent Field in Terms of the Coherent Green's Function Associated with Scattering of Waves in a Random Medium
Authors: Samaddar S. N.
Published: October 2017

Development of the fundamental equation for the multiple scattering of electromagnetic waves by an ensemble of randomly distributed electrons is reviewed. From this expression integro-differential equations satisfied by the coherent electric field as well as the coherent dyadic Green's function are constructed. The scattered coherent field is then represented in terms of the coherent dyadic Green's function. In addition, analogous expressions are presented for the problem of scattering of electromagnetic waves from a fluctuating dielectric medium.
Pouvoir de transmission d'un système fente–fente en optique corpusculaire
Authors: Berger C. , Adnot A. , Carette J.-D.
Published: October 2017

A method to calculate the transmission properties of a slit–slit system in electronic optics is described. It includes the following steps: calculation of the electric field between the electrodes, calculation of the electron trajectories point by point as a function of the initial conditions, and finally counting of the electrons which reach the second slit. Calculated and measured values of the transmission efficiency for usual geometrical dimensions of this system are presented.
Ellipsoidal Shape Parameters of Even–Even Nuclei in the Rare Earth Region with Continuum Model
Authors: Deshpande V. K. , Prakash V. R.
Published: October 2017

The rotational flow model applied to the ground state rotational band of even–even nuclei in the rare earth region, assuming spheroidal shapes, has been extended to include ellipsoidal shapes. The higher K = 2 rotational band is also analyzed. The conditions for obtaining a rotational spectrum in the continuum model are explored.
Electron Impact Ionization of Inert Gases
Authors: Khare S. P. , Padalia B. D. , Nayak R. M.
Published: October 2017

Electron impact total ionization cross sections of neon, argon, krypton, and xenon have been calculated for the electron impact energy varying from threshold to 20 keV. The method of Khare and Padalia, modified to include approximately the effect of multi-ionization, has been employed. The results are in fair agreement with the experimental data.
Single Particle Potential in Polarized Nuclear Matter
Authors: Dabrowski J. , Haensel P.
Published: October 2017

The problem of the single particle potential U in isospin and spin polarized nuclear matter, i.e. in nuclear matter with neutron excess and nonvanishing spin, is treated within the frame of the K matrix theory. General expressions for the isospin, spin, and spin–isospin parts of U, Uτ, Uσ, and Uστare obtained with the help of K matrices which depend on two Fermi momenta. The σ and στ parts have scalar and tensor components: Uσs and Uσt, and Uστ,s and Uστ,t These general expressions are specialized for nucleons at the Fermi surface. With suitable approximations, numerical values for Uτ(kF), Uσs(kF), and Uστ,s(kF) are obtained for the Brueckner–Gammel–Thaler and the Reid soft core nucleon–nucleon interactions. The tensor components, Uστ and Uστ,t, are estimated to be much smaller than the corresponding scalar components. The rearrangement effects turn out to be very important. At higher nucleon energies the τ, σ, and στ parts of U are calculated in the phase shift approximation with the Yale and Livermore phase shifts. The agreement of the calculated value of U, with experiment is satisfactory. The calculated values of Uσs and Uστ,s suggest that, in certain cases, a scalar spin–spin part of the optical potential is strong compared to other theoretical estimates, which seems to agree with some of the experimental results.
Magnetization Mössbauer Effect and Superconductivity in Fe2Te3
Authors: Hermon Erika , Muir W. B. , Quaroni J. , Sweet R. C.
Published: October 2017

The magnetization and Mössbauer effect in Fe2Te3 have been measured between liquid helium temperatures and 300 K and the Meissner effect has been studied between 1.7 and 4.2 K. Both the Mössbauer effect and the magnetization indicate that Fe2Te3 undergoes a weak ferromagnetic transition at about 10 K and has an internal field of 11 kOe at the lowest temperatures. The superconducting transition predicted by Atzeri and Mula was not observed. Above 10 K the temperature variation of the susceptibility is probably a reflection of the energy dependence of the d band density of states on the Pauli spin susceptibility of the material.
Correction for the Uniform WKB Wave Functions and the WKB Phase Shifts
Authors: Eu Byung Chan , Guerin Hervé G.
Published: October 2017

A method of improving the uniform WKB solution for single turning point problems is discussed and the correction formulas for the WKB phase shifts are obtained. The method involves the equation of motion which is in a form similar to that used by Fröman and Fröman to obtain the connection formulas in the WKB approximation. A sequence of solutions to the equation of motion is obtained in a remarkably compact form—and in a novel way—by utilizing the involutionality of certain 2 × 2 matrices appearing in the equations. A numerical test of the result thus obtained is presented in comparison with the corresponding numerical solution result. Unlike the ordinary WKB method, the present method is completely free of the connection formulas of the WKB approximation.
Theory of Pressure Broadening in an Adiabatic Representation
Authors: Royer Antoine
Published: October 2017

The theory of pressure broadening by foreign atoms is formulated within the framework of an adiabatic representation (which we distinguish from the adiabatic approximation). This allows us to treat all the electrons in the gas as indistinguishable, and thus include the possibility of electron exchange between atoms; this effect, which is responsible for much of the interatomic interaction, is neglected in all previous theories, apart from the adiabatic and 'nearest neighbor' theories which are of limited applicability. By means of projection operators, we define a spectral matrix, whose dimension is equal to the number of distinct frequencies characteristic of the isolated radiator. The spectrum is equal to the sum of all the elements of the spectral matrix; the diagonal elements correspond to the different lines of the spectrum, and the off diagonal elements represent quantum interference between overlapping lines. The Fourier transform of the spectral matrix is the correlation matrix, whose elements time correlate components of the dipole moment operator responsible for different lines of the spectrum. The time evolution of the zero perturber correlation matrix is given by eiΩτ, where Ω is a diagonal matrix whose elements are the different frequencies characteristic of the radiator. The perturbing gas causes the 'reduced Liouvillian' Ω to acquire a time dependent or frequency dependent non-Hermitian nondiagonal part. To obtain low density approximations, we treat that non-Hermitian 'perturbation' to first order in the gas density.
Thermal Noise in an Insulated Diode with Mobility as a Function of Carrier Density
Authors: Sharma Y. K. , Srivastava B. B. , Sharma V. K.
Published: October 2017

A formula is derived for the thermal noise in the case of a perfect trap free insulator whose mobility depends directly upon carrier density.
State Functions for Many Electron Atoms: Eigenfunctions of J2 and S2 for One Open Shell Configurations
Authors: Karwowski Jacek , Fraga Serafin
Published: October 2017

Eigenfunctions of J2 and S2 are constructed using a new formalism that represents an alternative to the Racah genealogical scheme. These functions have been tabulated for all the states arising from pN, dN, and fN configurations; this tabulation, not presented here because of space restrictions, is available as indicated in the text.
Erratum: Electromagnetic Induction in a Stratified Conducting Half-Space by an Arbitrary Periodic Source
Authors: Summers D. M. , Weaver J. T.
Published: October 2017

Null
Sound Velocity and Compressibility in the Liquid Alkaline Earth Metals
Authors: McAlister S. P. , Crozier E. D. , Cochran J. F.
Published: October 2017

Ultrasonic velocity measurements have been made on liquid Mg, Ca, Sr, and Ba to temperatures ~300 °C above the melting points. An empirical relationship between the sound velocity and surface tension is tested and found to hold well for the alkaline earth metals. Simple model calculations of the compressibilities at the melting points are found to be in disagreement with the experimental values.
Theory for the Excitation and Propagation of Electromagnetic Waves Guided by an Elevated Refractive Index Discontinuity in the Troposphere
Authors: Wait James R.
Published: October 2017

We present an analysis for waves guided by a smooth concave layer in the troposphere. The modal expansion includes both ground wave and Earth detached modes. It is shown that the excitation of the Earth detached modes by a ground based source is very weak. However, there is a possibility that these modes may be excited by a nonuniformity of the layer structure.
The Thermal Emission of Iodine
Authors: Brown J. David , Burns George
Published: October 2017

The temperature dependence of emission from iodine, heated in a shock wave to 1000 K–2000 K, has been measured at 4550, 5550, 6950, 7550, and 7820 Å. Preliminary measurements of the emission at 6380 Å were also made. The temperature dependence of the emission was calculated at these wavelengths for transitions to the ground electronic state X(1Σg+) of iodine from the excited electronic states, A(3Π1u), (1Π1u), and [Formula: see text]. The calculated results are in a reasonable agreement with experimental data. For the banded emission due to the B → X transition, a theory of the temperature dependence of emission was developed. At 6950, 7550, and 7820 Å, the results of this theory agree with the experimental data thus identifying the B → X transition as the source of emission at these wavelengths. The temperature dependence of emission at 4550 Å is consistent with calculated temperature dependence for either (1Π1u) → X or [Formula: see text] transitions. The temperature dependence of the emission at 5550 Å is consistent with calculated temperature dependence for the above two transitions, as well as for the A(3Π1u) → X transition.
Electron Precipitation at an Auroral Latitude – Saskatoon, L = 4.4. I. Photometer, Magnetometer, and Radiowave Data
Authors: Khan Z. M. , Manson A. H.
Published: October 2017

A study of the quiet and disturbed lower ionosphere (60–100 km) near solar maximum years (1970–1971) has been carried out at Saskatoon (52 °N, 106 °W, L = 4.4) using a variety of techniques: a 5577 Å photometer, a magnetometer, a 'partial reflection radiowave system' (2.2 MHz), and an all-sky camera.

Good correspondences between local and planetary magnetic disturbances and the green line intensity I(5577 Å) have been found. Radiowave data, ordered in terms of I(5577 Å), have been used in seasonal epoch analyses for the four seasons. It is shown that after the photometric maxima near geomagnetic midnight, ionospheric disturbances below 80 km continue to increase in magnitude towards sunrise. They are evident until at least noon the following day. For a given level of I(5577 Å), the ionospheric disturbance (< 90 km) is largest during the night hours in summer and winter; and after sunrise, largest in winter and fall months. There is good general correspondence between these results, and fluxes of precipitated electrons measured by satellite techniques.
Electron Precipitation at an Auroral Latitude – Saskatoon, L = 4.4. II. Fluxes of Precipitating Electrons
Authors: Manson A. H. , Khan Z. M.
Published: October 2017

Measurements of ambient electron densities have been made by the differential absorption experiment, on a number of aurorally disturbed nights in 1971. The measured values of the intensity of the green line (5577 Å) emission, and of the ambient electron densities, are then compared with theoretical estimates of these two variables. An exponential energy spectrum is used in the calculation, and fluxes of precipitated electrons (> 40 keV) and values for the e folding energies (E0) thereby become available. Comparisons of mean values with satellite measurements made under similar magnetic conditions, show good agreement. Calculations are also made for two specific nights, (January 26–28, 1971). Characteristic energies are typically 5 keV during the maximum of the magnetic and photometric disturbances, and increase to values of 10–15 keV near sunrise when the ionospheric disturbance (< 90 km) is greatest. The calculation is shown to be sensitive to changes in characteristic energy of the spectrum.
The Spectra of Ga IV and Ge V
Authors: Joshi Y. N. , Kleef T. A. M. van
Published: October 2017

The spectra of Ga IV and Ge V have been photographed recently on a 6.65 m normal incidence vacuum spectrograph using a sliding spark as a source. On the basis of our measurements, all the levels of Ga IV have been revised by +36.0 cm−1 while those of Ge V have been revised on the average by −32.7 cm−1. A new 3d94p3P10 level has been found in Ge V and 8 new lines have been added to this spectrum. We have interchanged the interpretation of the levels 3D20 and 1D20, and 3D30 and 1F30 of the 3d94p configuration in both spectra.
Calcul et mesure des forces et couples appliqués à un cristal uniaxe traversé par l'onde extraordinaire
Authors: Roosen Gérald , Imbert Christian
Published: October 2017

We derive from the Maxwell tensor the forces and torques applied to a uniaxial anisotropic crystal when an extraordinary wave passes through it, and we show that the momentum to be associated with the wave in the crystal is collinear with the Poynting vector.

Next, we present experimental results of torque measurements using, successively, two uniaxial anisotropic crystals placed inside a variable pressure container.

We finally compare our results with those obtained by other authors and show that, according to the types of experiments, either Abraham's or Minkowski's momentum density will appear. [Translated by the journal]
The Quantum Mechanical Second Virial Coefficient for Anisotropic Interactions: Hydrogen Molecule–Helium Atom
Authors: Larsen Sigurd Yves , Poll J. D.
Published: October 2017

A derivation of a generalized Uhlenbeck and Beth formula is given which relies neither on the notion of a box nor on formal scattering theory. The expression for the 2nd virial coefficient then involves bound state energies as well as eigenphase shifts associated with the asymptotic description of a coupled (open and closed) channel calculation. The proof and specific details of such a calculation are worked out for the case of a hydrogen molecule interacting with a helium atom.
Effect of Quantum Inhomogeneity Corrections in Semi-Statistical Thomas–Fermi Calculations for Atoms
Authors: Stauffer J. A. , Darewych J. W.
Published: October 2017

Approximate solutions to the Thomas–Fermi equation with so-called 'quantum correction terms' have been obtained by the use of a variational method. The results for krypton support the conclusions of Tomishima and Yonei that the coefficient of the gradient term should be 9/5 of the value derived by Kirzhnits. On the other hand, when the use of these equations is restricted to a region of the atom where the gradient expansion of Kirzhnits might be expected to be valid, the Kirzhnits value of the constant gives the better results, but the best results are obtained with no correction term at all (i.e. with the Thomas–Fermi–Dirac equation).
Wavelength Modulated Reflectivity and Photoconductivity of GaSb in a Magnetic Field
Authors: Langlois H. , Filion A. , Fortin E.
Published: October 2017

Measurements of the wavelength modulated reflectivity and of the photoconductivity have been made in the E0 region of GaSb at 4.2 K in the presence of a magnetic field. The results confirm the excitonic nature of the oscillatory photoconductivity near the gap and provide additional information necessary to achieve a line shape analysis.
Absorption Spectrum of the SiC2 Radical in the Gaseous Phase
Authors: Verma R. D. , Nagaraj S.
Published: October 2017

The stellar spectrum of certain N type stars in the blue–green region has been observed in the laboratory in absorption using the flash discharge technique. It has been interpreted as a 1Π ← 1Σ transition of the linear Si–C–C molecule. A new vibrational analysis has been proposed, which yields the following fundamental frequencies in cm−1.

[Formula: see text]

The 1Π state shows a small Renner splitting (εω2 = 3.3 cm−1). In addition, 001 and 040 levels are shown to perturb each other due to a Fermi resonance.
The Norms of Multimass States in Relativistic Quantum Field Theory
Authors: Palmer Roger , Takahashi Yasushi
Published: October 2017

We examined the problem of the appearance of negative norm states in multimass models. It is shown explicitly how the bound state with the same quantum numbers as the elementary meson, can acquire the positive norm. It is inferred from our argument that the multimass system of dynamical origin can be quantized without the negative norm, contrary to the multimass system of kinematical origin.
Zero Point Spin Deviation in MnO
Authors: Narayana P. A. , Gogan N. J.
Published: October 2017

The zero point spin reduction for antiferromagnetic MnO is calculated. Both 'theoretical' and 'experimental' values of overlaps are used yielding values of 3.2 ± 0.4% and 2.0 ± 0.2% respectively for the spin reduction.
Electric Dipole Transition Strengths in 19F
Authors: Johnstone I. P. , Castel B.
Published: October 2017

E1 transition strengths in, 19F are calculated using wave functions obtained by projection from three particle and four particle, one hole intrinsic states. With an effective charge which takes into account the influence of the giant dipole resonance, calculated B(E1) values are in agreement with experiment if the hole is allowed to have a reasonable p3/2 component.
High Energy Behavior in Infinite Channel Potential Scattering
Authors: Capri A. Z. , Kreuzer H. J.
Published: October 2017

We show that for an infinite channel potential scattering problem with bordered interaction, the resultant generalized optical potential is always a bounded function of the energy if it exists as an operator. Thus for this type of model no infinitely rising Regge trajectories are possible.
Density Dependence of Lorentz–Lorenz Coefficient for Sulfur Hexafluoride
Authors: Balzarini D. , Palffy P.
Published: October 2017

The Lorentz–Lorenz coefficient for sulfur hexafluoride has been measured over the density range 0.1 g/cm3 to 1.3 g/cm3. The critical density has been measured and is 0.736 ± 0.001 g/cm3. Refractive index and density are both measured in the same experiment yielding values of the Lorentz–Lorenz coefficient accurate to 0.05% for densities near critical. The method utilizes a prism-shaped high pressure cell which can be removed from a temperature controlled holder and weighed on a precision balance. The cell is equipped with a needle valve which allows the high pressure gas to be bled out in steps. Refractive index is measured as a function of weight and hence density. Studies of sulfur hexafluoride indicate a small variation of less than 0.5% over the density range covered. A knowledge of the density dependence is necessary for interpretation and verification of the validity of recent experiments near the critical points of pure fluids.
Quasilinear Theory of the Loss of Isotropy in a Plasma with Suprathermal Particles
Authors: Marquis E. , Teichmann J.
Published: October 2017

A magnetoplasma with isotropic distribution of particle velocities is unstable against the electron cyclotron modes, excited by the presence of a population of suprathermal electrons. The nonlinear interaction of these waves with resonant suprathermal electrons, whose initial velocity distribution was isotropic, causes diffusion in the velocity space. The distribution of suprathermal electrons becomes anisotropic. This may under certain conditions lead to new instabilities driven by the anisotropy in the velocity space. The temporal evolution of the 'plateau' and the characteristic relaxation time of the quasilinear interaction has been analyzed.
Thermoelectricity in Pure Iridium
Authors: Sellmyer D. J. , Franz J. M.
Published: October 2017

The thermoelectric power of pure iridium has been measured between 4 and 300 K. The results differ significantly from those reported by Carter et al., but they are consistent with high temperature results of Vedernikov and others. They also are quite similar to those reported by Huntley for rhodium. For [Formula: see text], the data can be expressed by S = αT + βT3, and possible origins for the T3 contribution are discussed.
Effective Masses of Quasifree Electrons in Inert Gas Solids
Authors: Brown R. G. , Davis H. T.
Published: October 2017

The Wigner–Seitz model for a core–core cutoff pseudopotential introduced by Springett et al. is used to predict effective masses of quasifree electrons in inert gas solids. The model has been useful in predicting or correlating ground state energies of electrons in liquid (Springett et al., Raz and Jortner, and Miyakawa and Dexter) and solid (Raz and Jortner) inert gases. The theoretical effective masses reported herein are at least a factor of two too high, even for Ne for which the model gives a good a priori prediction for the ground state quasifree electronic energy. The failure of the model in predicting excited state properties (namely, the effective masses) brings into question Miyakawa and Dexter's use of the potential barrier (Springett el al.) predicted by the same model in treating photoexcitation of electronic bubbles in liquid helium.
CO2 Laser Measurements on Shock Fronts
Authors: Strilchuk A. R. , Offenberger A. A.
Published: October 2017

CO2 laser measurements on reflectivity of shock fronts in N2, Ar, and CO2 at atmospheric pressure and N2 at low pressure are presented as well as results of shock velocity determination using a heterodyne technique. The measured and expected variation of reflectivity with angle of incidence show good agreement as do velocities compared with those determined using piezoelectric transducers.
Further Microwave Phase Measurements Associated with the Goos–Hänchen Shift
Authors: Read L. Arthur A. , Dagg I. R. , Reesor G. E.
Published: October 2017

Recent microwave phase measurement of the Goos–Hänchen effect dealt only with perpendicularly polarized radiation. The investigation is now complete and results for the parallel polarization are presented. These results also support the Artmann–Bezner theory previously discussed. Some speculatory remarks are included.
A Rotating Crystal Time of Flight Spectrometer Using a Pulsed Neutron Source
Authors: Egelstaff P. A. , Graham W. G. , Hahn L. , Suzuki K. , Winfield D. J.
Published: October 2017

The design and construction of a rotating crystal spectrometer for use with a pulsed neutron source is described. The source is the tungsten target of a 33 MeV electron linear accelerator, and at 5 kV mean power the spectrometer performance is equivalent to that of a similar instrument mounted on a nuclear reactor of 4 × 1012 n/cm2 s flux. Future developments will give an order of magnitude overall improvement. This spectrometer has been shown to be useful for studies of dense gases and liquids using an incident neutron wavelength of 2.4 Å, and its performance at wavelengths between 0.5 and 6.2 Å has been assessed.
The Magnetic Moments of the 3p5 Configuration of Atomic Chlorine
Authors: Uslu K. Altan , Code R. F. , Harvey J. S. M.
Published: October 2017

The paramagnetic resonance spectra of the ground 2P3/2 and excited 2P1/2 levels of both isotopes, 35Cl and 37Cl, of atomic chlorine have been observed. The off-diagonal magnetic dipole coupling constant A3/2, 1/2 and the metastable state g factor gj(2P1/2) have been evaluated from measurements on selected transitions to an accuracy of about two parts per million in the transition frequency. The magnetic dipole radial parameters [Formula: see text], [Formula: see text], and [Formula: see text] for chlorine are calculated.
Spectre d'émission de la molécule P18O : données nouvelles sur l'état E2Δ
Authors: Prudhomme J. C. , Coquart B.
Published: October 2017

Seven bands of the E2Δ–X2Πr system of the P18O molecule have been analyzed rotationally under a dispersion of 0.24 Å/mm. A study of the vibrational levels 0, 1, and 2 for the E2Δ state has been carried out. The perturbations and predissociations are discussed all together for P16O and P18O. The interaction between the E2Δ and C′2Δ states is confirmed. The molecular constants of the E state are readjusted by considering all its levels for P16O and P18O.
Vlasov Equilibrium in an Electrostatically Stoppered Magnetic Spindle Cusp Machine
Authors: Brunel F. , Lafrance G. , Burkhardt H. , Gregory B. C.
Published: October 2017

Numerical equilibrium solutions have been obtained for electrons and deuterium ions in a magnetic spindle cusp geometry combined with a stoppering electrostatic field. We give each species of particles a distribution function in terms of the constants of motion; such functions are solutions of the Vlasov equation. The Poisson equation is solved with charge distributions calculated from the moment of these distribution functions. Magnetic fields are not treated self-consistently. The calculations are two-dimensional. The parameters characterizing the plasma such as temperature and size, and the magnetic and electric field strengths are varied to a limited extent. We present the equilibrium solutions as profiles of densities and potential at certain sections of the machine and as equi-density contours.
Silver Film Atomic Oxygen Sensors: Further Evidence for Utility as an Atmospheric Probe
Authors: Henderson W. R.
Published: October 2017

Further evidence for the utility of thin silver films as detectors of atomic oxygen in the upper atmosphere is given. Measurements show that under prescribed conditions no correction for rate of oxidation or rate of change of oxidation is necessary.
The Magnetic Properties of Disordered Transition Metal Alloys Using the Coherent Potential Approximation and Related Methods
Authors: Zuckermann M. J.
Published: October 2017

For many years the properties of magnetic transition metal alloys were analyzed in terms of a rigid band model and the Stoner theory for magnetism in itinerant systems. Recently the introduction of the coherent potential approximation (CPA) has resulted in a description of the band structure of metallic alloys in terms of a local electronic charge density of states. The CPA and related approximations are derived in detail in this article and it is shown how these approximations have been extended to describe the properties of magnetic transition metal alloys in terms of local electronic spin densities. Both the statics and dynamics of itinerant magnetic alloys are discussed and the comparison with experiment is examined in detail. The article is concluded with a description of possible improvements to the CPA for magnetic alloys in particular for local environment effects.
Comparison of Secondary Electron Emission Due to Positron, Electron, and Positive Ion Bombardment
Authors: Pendyala S. , McGowan J. Wm.
Published: October 2017

The relative secondary electron yield under positron, electron, and positive ion (alkali ions: Na+ or K+) bombardment is determined for the cone of a spiraltron detector (Bendix Model 4219X). The method is based on the proportionality of yield to the mean of the pulse height distribution for the bombarding particle of a given energy. The ratio of the yields under electron and positron bombardments is found to be 1.2 to 1.0 for the semiconducting lead glass of the cone of the spiraltron through the energy range of 0.1 to 1.0 keV. Cherry found this ratio to be 3.0 ± 0.3 at 0.94 keV. The positive ion yield is ≈ 1.5 (absolute) throughout this energy range.
Optimization of Beat Frequency Plasma Heating near the Electron Cyclotron Frequency
Authors: Capjack C. E. , James C. R.
Published: October 2017

The plasma power absorbed from a beat frequency wave generated through the nonlinear mixing of two laser beams may be optimized by the utilization of an electron current resonance. The parametric dependence of the plasma power absorption near an electron resonance is examined together with experimental considerations for the case where CO2 lasers are used.
Crystal Dynamics of the Alloy Cu3Au
Authors: Hallman E. D.
Published: October 2017

Using inelastic scattering of slow neutrons, the frequency wave vector dispersion relations for the lattice vibrations in the disordered alloy Cu3Au have been measured at 296 K. The results are similar to those for copper, with the mean frequency ratio (alloy/copper) being 0.778. A Born–von Kármán fit to the data is given. Although detailed measurements of phonon widths have not yet been made, phonons were generally well defined, with no large scale resonance behavior of frequencies or widths observed.
Conduction Mechanisms in a-ZnTe
Authors: Webb J. B. , Brodie D. E.
Published: October 2017

The d.c. conductivity for a-ZnTe has been measured in the temperature range [Formula: see text]. Four distinct activated regions are observed and in most respects are consistent with the Davis and Mott model (DM model) for amorphous materials. Previous results on the frequency dependence of conductivity in a-ZnTe (Webb and Brodie) and recent measurements of the magnetoresistance and Seebeck coefficient are consistent with the analysis of the d.c. conductivity based on the DM model. A band picture for this material is obtained; however, the nature of the mechanism that gives rise to the fourth activated region < 77 K, is not accounted for in the DM model and no satisfactory explanation is available at present.
Electron Transport in Single Crystals of Niobium Dioxide
Authors: Bélanger G. , Destry J. , Perluzzo G. , Raccah P. M.
Published: October 2017

We have made measurements of the Hall effect and resistivity as well as of thermoelectric power in the temperature range 300–450 K. The results of these measurements are interpreted in terms of a small polaron model of conduction. Additionally, our resistivity and thermoelectric power measurements were extended to 1200 K in an attempt to elucidate the nature of the transition in conductivity occurring in the range 1071–1103 K. For the c direction, this transition appears to be from a semiconducting to a metallic state and a possible explanation for this is given in terms of a lattice distortion model.
The Raman Spectrum of Polycrystalline Perchloryl Fluoride
Authors: Sunder S. , McClung R. E. D.
Published: October 2017

The Raman spectrum of solid perchloryl fluoride has been obtained at 85 K for the regions of the fundamental vibrations. The bands show wide variations in their half-widths. The various factors causing broadening of the bands are discussed.
Erratum and Addenda: Theory of Electromagnetic Reflection From a Parallel Grid of Dielectric Coated Wires Buried in the Earth
Authors: Wait J. R.
Published: October 2017

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