bluuebunny/crossref_metadata_2025 huggingface dataset:
EXCITATION CURVES FOR THE (n, 2n), (n, p), AND (n, nα) REACTIONS OF 65Cu
Authors: Santry D. C. , Butler J. P.
Published: April 2011

Cross sections for the reactions 65Cu (n, 2n)64Cu, 65Cu(n, p)65Ni, and 65Cu(n, nα)61Co have been measured by the activation method from threshold energies up to 20.2 MeV. The measurements are relative to the known cross section for the reaction 32S(n, p)32P. The (n, 2n) cross-section curve increases smoothly with energy and reaches a maximum value of 1 085 ± 60 mb at about 18 MeV. The (n, p) reaction reaches a maximum value of 21.7 ± 1.2 mb at 13.9 MeV. The (n, nα) reaction has a minimum detectable value of 0.3 ± 0.1 mb near 14 MeV and increases to a value of 18.9 ± 0.9 mb at 19.8 MeV. Effective cross-section values for a fission-neutron spectrum calculated from these results are 0.251 ± 0.018 mb for the (n, 2n) reaction and 0.523 ± 0.030 mb for the (n, p) reaction.
DIFFRACTION BY A CONDUCTING HALF-PLANE IN PLASM
Authors: Chambers Ll. G.
Published: April 2011

The problem considered is that of a plane electromagnetic wave approaching from an arbitrary direction a perfectly conducting half-plane in an anisotropic plasma, characterized by a permittivity tensor. The system is such that the wave has a single magnetic field component, which is parallel both to the magneto-static field and the diffracting edge. The work is a simplification of previous work by Jull, involving the use of methods previously developed by the author.
BREMSSTRAHLUNG PRODUCTION IN 48-MeV p–p COLLISIONS
Authors: Warner Robert E.
Published: April 2011

Measurements of the cross section d2σ/dΩ1dΩ2 for the bremsstrahlung reaction p + p → p + p + γ were made with 48 ± 1 MeV incident protons. Both final protons were detected in coincidence at equal angles on either side of the beam and coplanar with the beam, and bremsstrahlung events were identified kinematically. Cross sections of 2.12 ± 0.36 and 3.04 ± 0.44 μb/sterad2 were obtained at 30° and 35°, respectively. Both measured cross sections are smaller than the predictions of Signell and Marker by about a factor of 10; this discrepancy is considered to be well established, since various tests show that our detection efficiency is nearly 100%. It is concluded that further theoretical work, especially predictions of cross sections for noncoplanar events, is needed to determine whether the discrepancy results from a strong preference for coplanar events or from some basic defect in the theory.
THE SCATTERING OF AN ELECTROMAGNETIC WAVE BY A SPHEROID
Authors: Senior T. B. A.
Published: April 2011

The problem of a perfectly conducting prolate spheroid illuminated by a plane wave at arbitrary incidence is considered. The known low-frequency solution is presented in a much simplified form, and, based on the symmetries now revealed, the next terms in the expansion are predicted.
THE ELECTRONIC ABSORPTION SPECTRUM OF THE PROPARGYL RADICAL
Authors: Ramsay D. A. , Thistlethwaite P.
Published: April 2011

A new system of diffuse bands in the region 2 900 to 3 450 Å has been found during the flash photolysis of propargyl bromide, propargyl chloride, methyl acetylene, allene, and other compounds. Isotopic studies have been carried out with five isotopically labeled parent compounds. The new bands are assigned to the propargyl radical, CH2—C≡CH. The diffuseness of the bands is attributed to predissociation of the radical in the excited state and gives an upper limit of 86.0 kcal/mole for the dissociation energy of the radical.
FIELD DEPENDENCE OF SPIN-LATTICE RELAXATION TIMES OF Cr3+
Authors: Rumin N.
Published: April 2011

Relative changes in the effective, one-phonon, spin-lattice relaxation time with transition, magnitude, and direction of magnetic field, frequency, and temperature have been computed for Cr3+ in K3Co(CN)6, Al2O3, and RbAl(SO4)2∙12H2O from a simplified expression for the transition probability requiring knowledge of only the spin Hamiltonian for the particular salt. A comparison with published experimental data, augmented by measurements obtained as part of the present work, indicates that the changes are usually predicted to better than a factor of two.Calculations show that the pulse saturation, resonance-dispersion, and steady-state saturation techniques should yield the same effective spin-lattice relaxation time for an S > 1/2 spin system, when the return to equilibrium is characterized by a simple exponential.
THE ALOUETTE II SATELLITE
Authors: Nelms G. L. , Barrington R. E. , Belrose J. S. , Hartz T. R. , McDiarmid I. B. , Brace L. H.
Published: April 2011

The successful launch of the Alouette II satellite is announced. A brief description is given of the experiments on board and some early indications of the results obtained are presented.
LOW-LYING NEGATIVE PARITY STATES IN THE A = 17 NUCLEI
Authors: Margolis B. , Takacsy N. de
Published: April 2011

The low-lying negative parity states of the A = 17 nuclei are calculated assuming a two-particle – one-hole structure. The level structure and the electromagnetic and β-decay transition rates are calculated and compared with experiment.
ON THE VIBRATIONAL FREQUENCIES OF THE HYDROGEN MOLECULE
Authors: Poll J. D. , Karl G.
Published: April 2011

The results of numerical calculations of the vibrational energy levels of the H2 molecule in the ground electronic state are presented. These were obtained by solving the Schrödinger equation for the nuclear motion using the adiabatic potential calculated by Kolos and Wolniewicz (1965). In agreement with experiment, it was found that H2 has 15 vibrational levels in the ground state. The vibrational transition frequencies agree with the experimental ones (Herzberg and Howe 1959) to better than one part in a thousand. For the lower levels, the remaining discrepancies can be accounted for using Van Vleck's (1936) estimate of the nonadiabatic frequency shifts. Results of similar calculations for D2 and T2 are also given.
THE BAND SPECTRUM OF HgA+
Authors: Santaram C. , Winans J. G.
Published: April 2011

The spectrum of a mixture of Hg vapor and argon excited by electrodeless discharge shows a system of bands with intensity maxima near 2 820 Å. Spectra obtained under various experimental conditions indicate that the emitter of this system is HgA+. These bands have been photographed with a dispersion of 1.2 Å/mm, and a vibrational analysis gives the following constants:[Formula: see text]The probable electronic transition for this system is A2Π–X2Σ+. The convergence limit in the upper state yields a value of 0.092 eV (741 cm−1) as the dissociation energy for the ground state.
ROTATIONAL ANALYSIS OF BANDS OF THE HCF MOLECULE
Authors: Merer A. J. , Travis D. N.
Published: April 2011

A new transient absorption spectrum, belonging to the HCF free radical, has been discovered in the flash photolysis of dibromofluoromethane, HCFBr2. The spectrum consists of a single progression of complex bands in the region 4 300–6 000 Å. Rotational analysis of the less severely perturbed bands shows them to be type-C bands of a molecule that is nonlinear in both upper and lower states of the transition, with bond angles of ~ 127° and ~ 102° respectively. Axis-switching effects, due to the large change of bond angle in the transition, cause the appearance of prominent gQ, qQ, and °Q branches, in addition to those obeying the ordinary type-C selection rules.The principal molecular constants of HCF (in cm−1) are:[Formula: see text]
35C1 AND THE UNIFIED MODEL
Authors: Taras P.
Published: April 2011

The experimental results obtained for 35Cl are interpreted in terms of the unified model. Members of live rotational bands can be identified. The band based on the ground state can be assigned K = 3/2 and positive parity. Of the three excited-state bands, two have positive parity and K = 1/2, while the third one has negative parity and K = 7/2.
THE ABSORPTION SPECTRUM OF THE P2 MOLECULE IN THE VACUUM ULTRAVIOLET
Authors: Creutzberg F.
Published: April 2011

The absorption spectrum of P2 has been photographed at high resolution down to 1 220 Å. Eight band systems have been analyzed, including two that were first observed by Dressier. Four of the excited states are identified as [Formula: see text] states and four as 1Πu states. Rotational and vibrational constants are given for the excited states, including improved constants for the previously known lowest excited [Formula: see text] state.
METEOR RADAR STATISTICS. II
Authors: Millman Peter M. , McIntosh Bruce A.
Published: April 2011

Mean daily values of meteor flux for three categories of meteor echoes are tabulated for the period 1958 to 1962. The variation of echo rate with echo duration is studied. The difficulty of using this relation to determine the mass distribution of meteoroids in interplanetary space is noted.
PHOTONS IN THE GRAVITATIONAL FIELD
Authors: Scott J. C. W.
Published: April 2011

In a previous paper, "The Gravitokinetic Field and the Orbit of Mercury," a new theory of gravitation was introduced, according to which space–time is always flat and the gravitational field is described by equations of Maxwellian form. In this paper it is shown that the theory correctly predicts the gravitational red shift and the gravitational deflection of a light ray. The interaction of photons with a gravitational field follows from the basic premises of quantum theory, that photon frequency is proportional to its energy and that photon wavelength is inversely proportional to its momentum. The photon velocity and proper mass depend on the gravitational potential, and the deflection of a light ray is due to gravitational refraction. The validity of the antisymmetric field equations for sources of variable rest mass is due to the divergence of the group velocity from the dynamical velocity.
ADMITTANCE OF A LONG LINEAR ANTENNA
Authors: Hurd R. A.
Published: April 2011

The admittance of a long tubular antenna of length 2h and small diameter is obtained as an asymptotic series in 1/h with terms 0(1/h2) included. Extensive numerical data are given. A comparison with the King–Middleton iterative approach indicates very close agreement. It is pointed out that, if certain integrals are tabulated, the restriction to small diameters almost disappears.
ATTENUATION OF ULTRASONIC WAVES OF ARBITRARY POLARIZATION AND PROPAGATION DIRECTION IN SUPERCONDUCTORS
Authors: Perz John M.
Published: April 2011

The attenuation by electrons of ultrasonic waves of arbitrary polarization and propagation direction is computed for superconductors on the BCS model, for the limiting condition that the electronic mean free path is much longer than the sound wavelength. The ratio of the superconducting to the normal attenuation is deduced. When the fermi surface has a high symmetry about the propagation direction, the attenuation of longitudinal and quasi-longitudinal waves follows the standard BCS expression. When symmetry is lacking, a sharp drop in longitudinal attenuation occurs within a small range of temperatures just below the transition temperature; the remaining attenuation follows the BCS result. The transverse attenuation behaves in a similar manner, regardless of the symmetry of the fermi surface. In all cases the residual attenuation depends on that part of the fermi surface for which electron velocities are normal to the propagation direction. These results are consistent with experimental data on attenuation in tin.
SOME EFFECTS OF NUCLEAR FORCES ON NEUTRON-STAR MODELS
Authors: Tsuruta Sachiko , Cameron A. G. W.
Published: April 2011

Two composite equations of state have been used in the investigation of the structure of neutron (or hyperon or baryon) stars. These have been based upon two forms of the neutron–neutron potential suggested by Levinger and Simmons. In one form, repulsive forces come in quickly at greater than nuclear densities, while, in the other form, the repulsive forces come in slowly. In the former case the maximum stable mass of a neutron star is about two solar masses, whereas in the latter case it is only about one solar mass. This probably represents a measure of the basic uncertainty in the properties of neutron-star models due to our lack of knowledge of nuclear forces. The maximum central density of a stable configuration is similarly uncertain; this density probably lies in the range 1015 to 1016 g/cm3. Details of many of the neutron-star models calculated are summarized and discussed.
THE LEVEL STRUCTURE OF 104Rh OBSERVED IN THERMAL NEUTRON CAPTURE
Authors: Hughes L. B. , Kennett T. J. , Prestwich W. V.
Published: April 2011

The capture gamma-ray spectrum of the reaction 103Rh(n, γ)104Rh has been studied using a Ge(Li) spectrometer. The energy range covered was from 3 600 to 7 500 keV with an average resolution of 12 keV. A total of 100 transitions were observed and the neutron separation energy was found to be 6 999 ± 3 keV.
ISOSPIN POTENTIAL TERM WITH LOCAL AND NONLOCAL INTERACTIONS
Authors: Sood P. C.
Published: April 2011

The isospin-dependent term in the nuclear potentials using nonlocal interaction is related to the corresponding term using local interaction employing the Perey–Buck local approximation. Relations are derived corresponding to two choices, with choice (a) corresponding to the same energy dependence of the neutron and the proton potentials, and choice (b) corresponding to the same range of nonlocality for the two potentials. It is concluded that for choice (a) a consistent description results if the potentials are written as V0(1 ± τ(N – Z)/A). For a given isospin dependence of the phenomenological local potential, the modification introduced is significantly different for the two choices; the importance of undertaking an analysis of the proton-scattering data with nonlocal potentials with a view to clarifying the situation is pointed out.
DIFFUSION IN MULTICOMPONENT METALLIC SYSTEMS: IX. INTRINSIC DIFFUSION BEHAVIOR AND THE KIRKENDALL EFFECT IN TERNARY SUBSTITUTIONAL SOLUTIONS
Authors: Kirkaldy J. S. , Lane J. E.
Published: April 2011

There are two methods of analysis for determining ternary intrinsic diffusion coefficients from experiment. In the first, the coefficients are derived from measurements of the mutual coefficients and the Kirkendall marker shifts. The experimental difficulties of making such measurements in ternary systems are formidable. As an alternative, a measurement of the tracer coefficients and the three independent mutual coefficients allows the calculation of the six intrinsic coefficients, and as a by-product yields the basis for calculating the Kirkendall shifts and estimating the thermodynamic properties of the solution.It is demonstrated by an approximate thermodynamic analysis for dilute solutions that the Kirkendall effect in ternary solution is the weighted mean of the effects for the two binary solute–solvent systems included and, therefore, has no unique significance. When one of the solutes is an interstitial, the Kirkendall behavior is approximately that of the substitutional binary pair.
NEUTRON-CAPTURE γ-RAY STUDIES IN 50Cr(n, γ)51Cr
Authors: Bartholomew G. A. , Earle E. D. , Gunye M. R.
Published: April 2011

Level energies and details of the γ-ray decay scheme in 51Cr are determined by Ge(Li) spectrometer and angular correlation techniques. Spin 3/2 is assigned to levels at 0.748, 1.898, 2.893, 3.125, and 3.769 MeV. A level at 776 keV, for which spin 1/2– is favored, may account for the anomalous lifetime previously reported for the 748-keV γ ray in 51Cr.
SOLAR MINIMUM MEASUREMENTS OF FAST NEUTRONS AT HIGH ALTITUDE
Authors: Baird G. A. , Wilson B. G.
Published: April 2011

Several rocket and balloon measurements of neutron intensity above Fort Churchill, Canada, were made during 1964 and 1965. The detector in each case was an anthracene–plastic "phoswich" using pulse-shape discrimination to distinguish between neutrons, gamma rays, and charged particles. Neutrons were recorded in the energy range 2–11 MeV. Measurements indicate that the albedo neutron flux is somewhat lower than theoretical predictions but is in agreement with reasonable extrapolations to zero atmospheric depth of measurements within the atmosphere made by other workers. The exponent of the differential energy spectrum appears to change from −1.4 at large atmospheric depths to −0.8 outside the atmosphere.
THE STATIC DIELECTRIC CONSTANT OF NaCl, KCl, AND KBr AT TEMPERATURES BETWEEN 4.2 °K AND 300 °K
Authors: Robinson M. C. , Hallett A. C. Hollis
Published: April 2011

Measurements of the static dielectric constant, εst, were made, using a transformer bridge with an absolute error of about 0.5% and a relative error of less than 0.02%. At 300 °K, the values obtained for εst were 5.90, 4.81, and 4.88, while 104(1/εst)(∂εst/∂T)p, was found to be 3.21, 2.93, and 3.10 (°K)−1 for NaCl, KCl, and KBr respectively, in good agreement with other recent measurements.At low temperatures, the curve of εst versus temperature was found to show a minimum, but it has not been found possible to explain all of the observed increase in εst with decreasing temperature below the minimum by the presence of impurities.The variation of εst with temperature is analyzed in detail on the basis of the evaluation made by Szigeti of the anharmonic contribution, G, to the dielectric constant. Estimates of (∂εst/∂T)v, which is equal to (∂G/∂T)v according to Szigeti (1961), have been made from the experimental data, and the curves of (∂εst/∂T)v versus temperature show an unexpected maximum at a temperature near θD/4,where θD is the Debye temperature.
THE DISTRIBUTION FUNCTION FOR IMPURITY STATES IN SEMICONDUCTORS
Authors: Barrie Robert , Cheung C. Y.
Published: April 2011

For a monovalent donor impurity in a semiconductor the number of electrons that can be bound to an impurity site is either zero or one. The one bound electron can have either direction of spin. This means that the usual Fermi–Dirac distribution function is not applied to such impurity states. A new derivation of the distribution function is presented in terms of annihilation and creation operators for the case of no interaction with the phonons. With the use of double-time temperature-dependent Green's functions, both the electron and the phonon distribution functions are derived when there is interaction between the bound electron and phonons.
STRUCTURE OF THE BAND SPECTRUM OF THE CuI MOLECULE: I. ROTATIONAL STRUCTURE OF THE E SYSTEM OF 63Cu127I
Authors: Rao P. Ramakoteswara , Apparao K. V. S. R.
Published: April 2011

The E band system of 63Cu127I, lying in the region 3 700 to 4 700 Å, has been photographed in emission under high resolution. Rotational analysis of the (0–4), (0–3), (0–2), (0–1), (0–0), (1–1), (1–0), (2–0), and (3–2) bands has been made. The electronic transition involved is found to be 1Σ (E1Σ)–1Σ(X1Σ). The rotational constants obtained are as follows:[Formula: see text]
THE b1Σ+–X3Σ− BAND SYSTEM OF NF
Authors: Douglas A. E. , Jones W. E.
Published: April 2011

If argon mixed with a small amount of NF3 is pumped rapidly through a mild discharge, a green glow is observed downstream from the discharge. This emission has been photographed with a high dispersion spectrograph and found to consist of a strong band with a head at 5 288 Å and a number of weaker bands. A rotational analysis of the bands has shown that they are the b1Σ+–X3Σ− bands of the NF molecule. The constants of the two states have been determined and it is found that for the ground state, ωe = 1 141.37 cm−1 and re = 1.317 3 Å.
INTERNAL GRAVITY-SHEAR WAVES IN THE TROPOSPHERE: II. WAVE AMPLITUDES
Authors: Naito Keikichi
Published: April 2011

Internal waves in a three-layer model of the troposphere are examined for amplitude of the perturbations about each interface. These amplitudes are significant only in the region of each interface, except at the longer wavelengths, where their influence may extend to the ground. Irregularities may occur in the vertical profile of perturbation amplitude, for some combinations of wavelength and interface separation. The motion of air particles at the interface is circular in many cases, as in deep-water waves. Approximate conditions for stability of internal waves are derived for a multilayer model; and it is shown from the analysis of height oscillation of the interface that the tendency for isolated roll motions to develop increases with decreasing wavelength, even when the atmospheric stratification is stable.
NUCLEAR QUADRUPOLE RESONANCE STUDIES IN CUPROUS OXIDE
Authors: Jeffrey K. R. , Armstrong R. L.
Published: April 2011

The 63Cu and 65Cu pure nuclear quadrupole resonance transitions have been investigated in a powder sample of cuprous oxide from 4.2 °K to 298 °K. The observed decrease in resonance frequency with increasing temperature is discussed in terms of the theory developed by Bayer and Kushida. The spin-lattice relaxation-time measurements above 20.4 °K are interpreted in terms of a coupling of the lattice phonons to the nuclear quadrupole moments via two phonon Raman processes. A rough estimate of the Debye temperature is made. The measured relaxation times at 4.2 °K are an order of magnitude shorter than predicted by the spin-phonon mechanism. Two other mechanisms are discussed: (i) a coupling of the spins to torsional oscillations; (ii) a coupling of the spins to paramagnetic impurities.
THE ν10 AND ν11 RAMAN BANDS OF GASEOUS ETHANE
Authors: Lepard D. W. , Shaw D. E. , Welsh H. L.
Published: April 2011

The degenerate ν10 and ν11 Raman bands of C2H6 have been photographed at a spectral resolution of ~0.4 cm−1 and a gas pressure of 1 atm. The rotational structures of both bands were analyzed. The analysis of the ν10 band gave A0 = 2.671 ± 0.005 cm−1 for the ground-state rotational constant A0. Although this value is between 3 and 4% higher than previous determinations, the method of analysis indicates that it must be considered the most reliable yet obtained. This new value of A0 has been used, with other data, to recalculate the ground-state geometrical structure of ethane.
DIRECT ELECTRIC-FIELD ELECTROTRANSPORT OF CARBON AND NITROGEN IN IRON AND IRON ALLOYS
Authors: Bibby M. J. , Hutchinson L. C. , Youdelis W. V.
Published: April 2011

The interstitial mobility of carbon and nitrogen in austenite iron is determined from diffusion experiments carried out in a direct electric field. Diffusion-penetration curves are obtained, using a microhardness technique, and related to the "apparent charge" of the solutes by the Einstein equation. The apparent charge of carbon is positive, increasing from +8.6 ± 1.0 at 950 °C to +13.7 ± 1.7 at 842 °C. The apparent charge of nitrogen is negative, increasing from −8.3 ± 1.0 at 1 000 °C to −14.1 ± 1.7 at 922 °C. Positive Hall coefficients are found for both systems at 925 °C. The effect of 4% manganese in iron is to increase the apparent charge of carbon to ~ +9.3, while 2% silicon in iron decreases the apparent charge of carbon to ~ +4.7 at 950 °C. The results obtained are discussed in relation to the band structure of the alloys and the effect of electron or "hole" momentum transfer to the lattice. A possible alternative mechanism is also proposed which could contribute to the high apparent charge obtained for the solutes.
CALCULATION OF THE PRESSURE BROADENING OF ROTATIONAL RAMAN LINES DUE TO MULTIPOLAR AND DISPERSION INTERACTION
Authors: Gray C. G. , Kranendonk J. Van
Published: April 2011

The impact theory of Raman line broadening is applied to the broadening of the rotational Raman lines of diatomic molecules arising from electric multipole and anisotropic dispersion forces. Expressions are derived for the elastic and inelastic optical cross sections, and these are evaluated for the self-broadening in N2, O2, CO, and CO2, using values of the molecular constants obtained from sources independent of the line-broadening experiments. Included in the calculations are the "time", or "resonant", factors in the optical cross sections, and the resulting time integrals are explicitly evaluated for arbitrary multipole interactions, and anisotropic dispersion forces of second and fourth degree in the orientations. The overall agreement between the theoretical and experimental values of the magnitude of the half-widths is satisfactory, but a discrepancy appears in the variation of the broadening with the rotational quantum number. Possible explanations of this discrepancy are suggested in view of the results on foreign-gas broadening by monatomic gases.
THE ICE NUCLEATION BEHAVIOR OF AMINO-ACID PARTICLES
Authors: Maybank J. , Barthakur N.
Published: April 2011

The problem of whether ice nucleation takes place more readily from the vapor directly to the solid, or via an intermediate liquid phase has been studied for several of the more efficient amino-acid nucleators. It has been shown that the threshold temperatures observed in cloud chamber tests are in fact those of the material acting as freezing nuclei (i.e. via the liquid phase), and any discrepancies between such tests and trials with bulk water may be accounted for satisfactorily by partial destruction of the nucleus surface by the water. Investigations on ice formation about airborne particles and on macroscopic amino-acid crystals have shown that for certain of these substances a transition in behavior takes place around −20 °C. Below this temperature, ice formation no longer requires saturation conditions with respect to supercooled water and so the particles may be considered to act by converting the vapor directly to ice, and can, therefore, be designated sublimation nuclei.The major obstacle in the way of airborne particles acting as freezing nuclei has been the requirement that they act first as condensation centers. Under the conditions prevailing in supercooled clouds with vapor pressures equal to, or barely exceeding that of water saturation, condensation is unlikely on the somewhat hydrophobic surfaces of amino-acid particles. It has been shown, however, by using a radioactive tracer in small water droplets that droplet–particle collisions can occur. While not efficient, this process would permit a few particles in a cloud chamber experiment to act as freezing nuclei, thereby establishing the potential activity of the material itself.
THE ABSORPTION SPECTRUM OF SH AND SD IN THE VACUUM ULTRAVIOLET
Authors: Morrow B. A.
Published: April 2011

The absorption spectrum of SH in the vacuum ultraviolet has been obtained by the flash photolysis of hydrogen sulfide. Transitions from the 2Π ground state to seven excited states have been observed and four of these fit reasonably well into a Rydberg series. From an extrapolation to the convergence limit of this series, a value of 10.40 ± 0.03 eV for the ionization potential of SH has been derived. Values for the rotational constants of these new electronic states have been determined; corresponding data for SD have also been obtained. The (1–0) transition of the system near 1 670 Å (B2Σ–X2Π) was observed, and, with the aid of isotope relations, vibrational constants of the B state have been derived. An estimate of the dissociation energy of SH in this excited state is D0′ = 24 190 ± 1 000 cm−1.
SCATTERING OF ELECTROMAGNETIC WAVES BY A SINUSOIDALLY STRATIFIED HALF-SPACE: II. DIFFRACTION ASPECTS AT THE RAYLEIGH AND BRAGG WAVELENGTHS
Authors: Tamir T.
Published: April 2011

The diffracted field of a plane wave incident obliquely from air onto a sinusoidally modulated half-space is investigated by employing a rigorous formal solution, together with graphical constructions and equivalent circuits, which have already been derived by Tamir and Wang (1966, Part I). The field in the air region is shown to be influenced considerably by Wood's anomalies of the Rayleigh type. The location of these anomalies is determined by the onset of propagation or evanescence for modes in either the air or the dielectric regions; their orders of magnitude are estimated by means of a network which describes the air–dielectric interface. In the stratified dielectric, the field is strongly affected by an interference process that peaks at the Bragg wavelengths and produces a resonant behavior of the modal amplitudes. This results in a strong standing-wave field pattern in the form of repetitive oblong rectangular cells with interesting power-flow properties. Additional details of the fine field structure are treated extensively and numerical data, which are in excellent agreement with the considerations and results obtained by analytical and graphical means, are given.
QUANTUM CELL MODEL FOR He II AT NONZERO TEMPERATURE
Authors: Knollman G. C.
Published: April 2011

A previous quantum cell-model development is expanded to treat the solid-superfluid phase transition and the zero-momentum occupation at temperatures other than absolute zero. Application is made to liquid He II, which is studied at various pressures out to temperatures of about a degree absolute. The effective repulsive energy, along the solid–superfluid transition, is determined for pairs of 4He atoms localized in cells of volume equal to the specific volume.
THE SCATTERING OF PROTONS ON 7Li, 9Be, AND 12C AT 100 MEV
Authors: Mark S. K. , Portner P. M. , Moore R. B.
Published: April 2011

Elastic and inelastic scattering of protons on 7Li, 9Be, and 12C have been studied, using the 100-MeV proton beam from the McGill synchrocyclotron. Differential cross sections for the various groups of scattered protons were measured over an angular range of 5° to 90° (lab). For proton groups resulting from a quadrupole excitation in the target nucleus, the angular distribution was found to increase at scattering angles less than 10°. Angular distributions corresponding to an octupole excitation were observed to decrease at small angles. The results have been compared with existing data in this energy region.
THE TEMPERATURE DISTRIBUTION PRODUCED BY ACOUSTIC ABSORPTION: I. MACROSCOPIC TREATMENT
Authors: Simons S.
Published: April 2011

A calculation is given of the temperature distribution in space and time produced by the absorption of an acoustic wave propagated inside a medium, under conditions in which the situation may be described macroscopically. The problem is considered for various geometries, and for both constant and time-dependent energies of the incident acoustic wave. Numerical results are obtained, and a discussion is given of their relevance to various experiments.
MAN-MADE TELLURIC MICROPULSATIONS
Authors: Jones F. W. , Kelly A. M.
Published: April 2011

Man-made telluric micropulsations in the frequency range 0.001 2 Hz to 0.12 Hz have been investigated near Montreal, Canada. Distinct telluric signals caused by electric-train activity have been identified and compared with the associated magnetic effects. The results indicate that some electromagnetic disturbances of this kind may be more easily detected and identified by telluric means than by magnetic means.
THE HALF-LIFE OF RUBIDIUM-87
Authors: McMullen C. C. , Fritze K. , Tomlinson R. H.
Published: April 2011

The quantity of 87Sr produced from the decay of 87Rb during an accurately known period of time has been determined. The analysis of the 87Rb and the 87Sr content of four different rubidium samples was performed by mass spectrometry. A value of (4.72 ± 0.04) × 1010 years was calculated from the results of the measurements for the half-life of 87Rb.
NEW ALPHA-DECAY BARRIER PENETRABILITIES WITH IGO POTENTIAL: ODD-MASS NUCLEI
Authors: Kohlmann L. , Vörös T.
Published: April 2011

Barrier penetrabilities, reduced widths, and hindrance factors are given for odd-mass alpha-particle emitters measured after 1959. The method of calculation is as in a previous publication. The calculated quantities are given for the total decay energy.
RADIATION FROM AN ELECTRIC DIPOLE IN A MAGNETOPLASMA
Authors: Seshadri S. R.
Published: April 2011

The fields radiated by an arbitrarily oriented electric dipole in an unbounded, loss-free magnetoplasma are synthesized in terms of cylindrical waves, with the direction of the magnetostatic field as their axis of symmetry. Six independent modes specified by two radial and three azimuthal mode numbers are found to be excited. The total radiation resistance of the electric dipole is shown to be obtainable as the superposition of the contributions arising from the individual modes. Integral expressions for the radiation resistance due to the various modes are obtained and are used in the numerical evaluation of the radiation resistance for some typical values of the parameters of interest. The radiation resistance of an arbitrarily oriented electric dipole is found to become infinite in two frequency ranges on account of the gyro- and plasma resonances, as well as at the upper hybrid resonant frequency, and a discussion of the procedure for eliminating the infinite behavior of the radiation resistance is included.
A Ge(Li) COUNTER INVESTIGATION OF THE GAMMA-RAY DECAY OF 28Si PRODUCED IN THE REACTION 27Al(p, γ)28Si
Authors: Azuma R. E. , Carlson L. E. , Charlesworth A. M. , Jackson K. P. , Anyas-Weiss N. , Lalović B.
Published: April 2011

A large (17 cm3) lithium-drifted germanium detector has been used to observe the γ-ray deexcitation of 28Si produced at several proton resonances in the 27Al (p, γ)28Si reaction. The decay schemes have been deduced and compared with those previously published. In the present paper a detailed account is given for the Ep = 992-keV resonance only.
RELATIVISTIC PRECESSION OF A SPINNING SATELLITE
Authors: Rastall Peter
Published: April 2011

The precession of the spin angular velocity of a small, spherically symmetric satellite is calculated by a geometrical method. The gravitational field is not assumed to be spherically symmetric, and metrics of the Lense–Thirring type are allowed.
STRUCTURE OF A BUNCH OF CHARGE IN AN IDEAL ACCELERATOR
Authors: Newton T. D.
Published: April 2011

A bunch of charged particles is considered to be moving in a long conducting tube subject to external time-independent focusing forces. The density of the particles in the bunch and the electromagnetic field of the bunch of charge in the conducting tube are determined simultaneously.The parameters of the idealized accelerator may be obtained from those of an actual machine design, so that predictions of bunch shape and effects of space and image charges on phase areas (emittances) may be made.
THE THERMAL CONDUCTIVITY OF PLATINUM BETWEEN 300 AND 1 000 °K
Authors: Laubitz M. J. , Meer M. P. van der
Published: April 2011

The thermal conductivity of high-purity platinum was measured between 300 and 1 000 °K. The results obtained agree very well with the previously reported work of Bode and of Martin and Sidles, but at higher temperatures are in definite disagreement with the results of Powell and Tye. The observed variation of the thermal conductivity with temperature implies that at high temperatures the (electronic) Lorenz number of platinum is an increasing function of temperature, exceeding in magnitude the Sommerfeld value. Such behavior of the Lorenz number can be understood qualitatively if one assumes a low Fermi energy for platinum, an assumption usually made to account for the behavior of its high-temperature electrical resistivity.
VACUUM-ULTRAVIOLET EMISSION AND ABSORPTION SPECTRUM OF THE NO MOLECULE: THE 2Δ STATES AND THEIR INTERACTIONS
Authors: Jungen Ch.
Published: April 2011

The emission spectrum of NO between 1 600 and 1 400 Å has been studied with a 1-m vacuum spectrograph. It consists of the two types of mutually perturbing 2Δ–X2Π bands already known from the much more complex absorption spectrum: the Rydberg systems F2Δ–X2Π, N2Δ–X2Π and the non-Rydberg system B′ 2Δ–X2Π. The interactions between the excited states of different electron configurations are of special interest. The matrix elements H = Hvib ∙ He have been obtained from detailed rotational analyses, a "deperturbation" in two steps has been carried out, and constants for the deperturbed 2Δ states are given. With calculated overlap integrals Hvib, the electronic configuration interaction energy He is derived. "Crossing" potential energy curves have been shown to be the appropriate zero-order approximation when [Formula: see text]. The phase of the interaction, i.e. the sign of He, has been deduced from the perturbed intensities of the observed bands.
NUMERICAL SOLUTIONS TO ELECTROMAGNETIC SCATTERING FROM STRIPS, FINITE WEDGES, AND NOTCHED CIRCULAR CYLINDERS
Authors: Billingsley J. B. , Sinclair G.
Published: April 2011

Accurate far-field scattering patterns and backscattering cross sections are numerically calculated for perfectly conducting strips, finite (circular sector) wedges, and sectorally notched circular cylinders, all infinitely long, under transverse electric or transverse magnetic plane-wave illumination normally incident to the cylinder axis from any direction. The notch or wedge angle is arbitrary. Results have been obtained for cylinders and wedges of radius as large as five wavelengths, and strips as wide as two wavelengths, without straining an IBM 7094 digital computer.
LOW TEMPERATURE RECOVERY OF DEFORMED ZIRCONIUM
Authors: Swanson M. L.
Published: April 2011

The low-temperature recovery of the electrical resistivity increment Δρ0 produced by deformation of polycrystalline Zr at 4.2 °K was investigated. Particular attention was given to the large recovery stage occurring between 30° and 40 °K, which amounted to 30% of Δρ0 for Zr containing ~0.070 at. % oxygen, but only 6% of Δρ0 for Zr containing ~0.015 at. % oxygen. By means of isochronal and isothermal anneals, this recovery stage was shown to be due to several first-order annealing processes (with activation energies between 0.105 and 0.125 eV), which were attributed to defect-oxygen atom interactions. Additional recovery peaks were observed at 190 °K and 310 °K only for the lower purity Zr, whose recovery to 360 °K was approximately 80%.
STUDIES OF AURORAL HYDROGEN EMISSIONS IN WEST-CENTRAL CANADA: II. VARIATIONS IN THE INTENSITY RATIO BETWEEN THE Hβ LINE AND THE λ 4 709 N2+ BAND
Authors: Montbriand L. E. , Jones A. Vallance
Published: April 2011

The results of a large number of measurements of R(Hβ), the intensity ratio of the Hβ auroral line, and the λ 4 709 (0, 1) first negative N2+ band from Canadian IGY patrol spectrograms are presented. Only 3% of these ratios exceed unity, while half of them are less than 0.2. Comparison with a theoretical value of about 3.0 for proton excitation indicates that only a small fraction of aurora is so excited. The rare occurrence of values of R(Hβ) near 3.0 suggests that pure proton excitation does sometimes occur, however. Values of ratios of the brightnesses of Hβ averaged over several spectrograms to those of λ 4 709 similarly averaged have been shown to exhibit geomagnetic, latitudinal, and diurnal variations. The highest average ratios occur in the early evening, while the lowest values are observed in the late morning in post-breakup forms. The diurnal and latitude variations in these average ratios support the hypothesis that there is a zone of proton precipitation showing a characteristic behavior relative to the zones of electron excitation.
PLASMA-INDUCED INTERFERENCE IN SATELLITE v.l.f. RECEIVERS
Authors: Osborne F. J. F. , Smith F. H. C. , Barrington R. E. , Mather W. E.
Published: April 2011

Under specific circumstances, the v.l.f. receiver (400 Hz–10 kHz) aboard the Alouette I spacecraft has observed an interference signal originating with an electrical converter system. The chief characteristics of this signal are that it appears only in daylight operation and is spin modulated in such a manner that signal nulls appear when the spacecraft is oriented for minimum V × B effects. To explain these features, a mechanism was postulated which involves a coupling of the converter signals via the power-supply internal impedance and the solar-cell chain to the plasma environment and thus to the v.l.f. antenna, but requiring the asymmetry of the V × B sheaths for coupling. In order to test the validity of this theory, a simple satellite model was immersed in a low-density plasma, and operations under different space conditions were simulated. It was shown that the system design of the spacecraft could permit observation of such an interference signal under the required conditions.
THE HALF-LIVES OF THE 243-keV AND 188-keV LEVELS IN 125I
Authors: Horowitz Y. S. , Moore R. B. , Barton R.
Published: April 2011

The half-lives of the 243-keV and 188-keV levels in 125I were measured, yielding T1/2 = 2.1 ± 0.2 × 10−10 seconds for the 243-key level and T1/2 = 3.4 ± 0.2 × 10−10 seconds for the 188-keV level. Partial half-lives were calculated, indicating that the E2 transition rates are enhanced over single-particle estimates by a factor of 30 and hence are collective in nature.
EFFECT OF ION SHEATH ON RADIATION IN A MAGNETOIONIG MEDIUM: II. SOURCE CURRENT PERPENDICULAR TO THE MAGNETOSTATIC FIELD
Authors: Seshadri S. R. , Bhatnagar K. L.
Published: April 2011

The radiation characteristics of current sources situated along the axis of an infinite cylindrical column of free space and surrounded by a homogeneous, loss-free magnetoionic medium are discussed for the case in which the source current is perpendicular to the magnetostatic field. The static magnetic field is assumed to be parallel to the axis of the free-space column, which is an idealization of the ion sheath formed around the antenna in the ionosphere. Both a point electric dipole and a finite and continuous array of the same are investigated. The dependence of the radiation resistance of these sources on the frequency and the ion-sheath thickness is examined. Even in the limiting case of vanishing thickness of the ion sheath, the radiation resistances of these sources are found to be different from those corresponding to an unbounded plasma. In contrast to those in an unbounded magnetoplasma, the radiation resistance remains finite for all frequencies. For the source of finite extent having a current distribution that falls off sufficiently rapidly towards the ends, the radiation resistance is quite insensitive to the changes in the thickness of the ion sheath.The radiation-resistance curve, in general, has two peaks at the so-called dipolar resonant frequencies, which depend primarily on the strength of the magnetostatic field. These dipolar resonances, which are quite analogous to those in an axially magnetized plasma column, are found to become sharper as the radius of the free-space column becomes smaller.
ON THE METHODS OF MEASURING CHANGES OF ELECTRICAL RESISTIVITY
Authors: Míšek K.
Published: April 2011

Indirect methods of measuring resistivity changes in thin metallic wires, which are due to the presence of lattice defects, are described. These methods are useful when the direct measurement of resistivity changes cannot be carried out, owing to the unsuitable dimensions of the specimen or owing to its nonuniform cross section. Also the size-effect correction of the excess resistivity is discussed, as it may be of some importance at low temperatures in a specimen of small diameter prepared from very pure metal. Some examples of measurement are given and the applicability and limits of indirect methods are discussed.
ON THE KINETIC THEORY OF A VAN DER WAALS GAS
Authors: Sobrino Luis de
Published: April 2011

A kinetic equation is proposed that leads, in equilibrium, to the Van der Waals equation of state. It is shown that this kinetic equation obeys an H theorem, and that its equilibrium solutions are, in the condensation region, of two types, (i) inhomogeneous equilibrium solutions which are absolutely stable and correspond to the two phases in equilibrium, (ii) homogeneous equilibrium solutions which are not absolutely stable but are, if the compressibility is positive, stable against small dynamical (i.e. nonquasi-static) perturbations, and correspond to the metastable states of the system. As a result, it is seen that a linear theory cannot explain the transition from the metastable to the stable states. A system of simplified nonlinear equations for the first three velocity moments of the distribution function is obtained in the hope that its study will contribute to the understanding of the mentioned transition.
ION–ION RECOMBINATION COEFFICIENT: II. MEASUREMENTS IN OXYGEN–NITROGEN MIXTURES
Authors: McGowan S.
Published: April 2011

Ion–ion recombination coefficients were measured at pressures ranging from 50 to 800 Torr for four oxygen–nitrogen mixtures which had been passed through cold traps at temperatures just above the boiling points of the gas samples. The following values of α were obtained at 1 atm and 25 °C: in O2, (2.00 ± 0.10) × 10−6 cm3/sec; air, (2.21 ± 0.10) × 10−6 cm3/sec; N2 with 1% O2, (2.24 ± 0.10) × 10−6 cm3/sec; N2 with 0.001% O2, (2.45 ± 0.15) × 10−6 cm3/sec. The observed pressure dependence of α followed that predicted by Natanson's theory.Considerably lower values of about 1.6 × 10−6 cm3/sec were found for untreated air, and a further reduction to about 1.4 × 10−6 cm3/sec was observed when surfaces, which had been coated with a colloidal suspension of graphite in alcohol, were present.
THE NATURE AND FORMATION OF BANDS OF DEFORMATION IN SINGLE CRYSTALS OF α-PHASE COPPER–ALUMINIUM ALLOYS
Authors: Mitchell J. W. , Chevrier J. C. , Hockey B. J. , Monaghan Jr. J. P.
Published: April 2011

The mechanism of the deformation in tension of [321] axis square-sectioned single crystals of α-phase copper–aluminium alloys with [Formula: see text] and [Formula: see text] surfaces has been studied. Extensive use has been made of interference microscopy and carbon replicas for the determination of the surface topography of the bands of deformation. It has been shown that, in addition to the discrete slip lines which are seen with the optical microscope and in replicas, there is a background of plastic deformation on a much finer scale which is not resolved. The integrated step height across bands of deformation corresponding with this fine slip can be measured on the interferograms. The integrated step height between corresponding points on the opposite [Formula: see text] surfaces was found to be equal. The studies of surface topography were supplemented by work on the nature of the distributions of dislocations within the crystals by etching and transmission electron microscopy. It was found that the dislocations are largely present as interleaved pileups of parallel positive and parallel negative dislocations in near-edge orientations and as closely spaced multipolar distributions. Large pileups of several hundred dislocations have been observed and correlated with surface slip lines. They appear to be introduced as avalanches from surface sources. Characteristic features of this previously unrecognized type of band of deformation have been established and the mechanism proposed for the formation of the bands recalls many of the features of the dynamical model for the multiplication of dislocations discussed by Frank in 1947. The background on which the slip lines are superimposed appears to be due to the limited activation by the shear stress within the band of deformation of a uniform distribution of sources.
THERMALLY ACTIVATED DEFORMATION OF α TITANIUM BELOW 0.4 TM
Authors: Conrad H.
Published: April 2011

The effects of temperature, strain rate, and purity on the yield and flow stresses of α titanium at low temperatures (T < 0.4 TM) are examined to ascertain the rate controlling dislocation mechanism. The effect of impurity content on the thermal component of the yield and flow stresses increases with the decrease in temperature to 0 °K. The activation volume for the plastic flow of titanium of commercial purity ranges from 80b3 at τ* = 1 kg/mm2 to 8b3 at τ* = 45 kg/mm2. The activation energy ranges from about 1.3 eV to 0.18 eV over the same stress range. The experimental data are in good accord with the thermally activated overcoming of interstitial atoms as the rate controlling mechanism and a linear force-distance curve with FM = 43.2 × 10−6 dynes (0.9 × 10−1 μb2), d0 = 3.25b, and H0 = 1.25 eV (0.21 μb3).