bluuebunny/crossref_metadata_2025 huggingface dataset:
ON THE APPLICATION OF ASTON BANDS AND APPEARANCE POTENTIAL MEASUREMENTS TO ION COLLISION STUDIES
Authors: McGowan Wm. , Kerwin Larkin
Published: April 2011

Two techniques are applied to ion collision studies. The first, Aston banding, is native to mass spectrometry, and effectively makes of a simple mass analyzer a double mass spectrometer which separates unambiguously the parent ions from the products. By combining with the mass spectrometer a "high-pass" energy filter, we are able to study ionic collisions which take place in the drift regions both before and after the magnetic analyzer. We describe the methods whereby we measure total cross sections for both charge exchange and collision-induced dissociation and show how we measure the loss and distribution of energy and momentum of the high-velocity product ions. The accelerating potential range for our ion collisions is 0.6 to 2.0 kv.The second technique, the detailed comparison of appearance potential curves, complements Aston banding although it has broader application. We describe how, from the ratio of the A.P. curve of the product to that of the parent, one can determine directly the influence of metastable or long-lived excited ions in the parent ion beam. We further describe how, from the ratio of the differences of slopes, one can determine the relative and sometimes the absolute cross sections associated with these states of the ion which enter into collision with a particular ion kinetic energy. In this paper, the techniques and the conditions under which they are applicable are stressed. In subsequent papers, we shall discuss results obtained with the techniques involving ions coming from Ar, H2, N2, and O2.
EXPERIMENTAL STUDY OF THE AMPLITUDE OF RADAR METEOR-HEAD ECHOES
Authors: McIntosh B. A.
Published: April 2011

Measurements are presented on some 500 radar meteor-head echoes observed during the 1961 Perseid meteor shower. Mean absolute powers of head echoes and of the associated enduring echoes are given as a function of the angular position of the meteor along its trajectory. The detailed amplitude variation of three head echoes is discussed in relation to various scattering mechanisms. It is shown that a solar-controlled parameter of the atmosphere has a strong influence on head echoes.
THE MAGNETIC TORQUE EXERTED ON A FINITE CYLINDRICAL CONDUCTOR SLAB BY A "ROTATING" MAGNETIC FIELD
Authors: Lengyel L. L.
Published: April 2011

A cylindrical conductor of finite length revolves slowly in a magnetic field given by a constant, rotating field vector. The magnetic flux lines are normal to the axis of the cylinder. The induced axial currents are deflected at the ends of the conductor slab, and a three-dimensional, antisymmetric current distribution results. A perturbation technique is applied to the nondimensional equations defining the electromagnetic field and force distributions. The zeroth-order solution corresponding to an unperturbed magnetic induction field is carried out in detail. The end effects are found to be substantial if the length to diameter ratio is less than 5.
SURFACE-WAVE PROPAGATION OVER PLANE-LAYERED DIELECTRICS
Authors: Morris D.
Published: April 2011

A two-layer dielectric system, consisting of a thin polystyrene sheet on top of water, is examined as a possible guiding structure for surface waves. Experimental investigations, at a frequency of 9.35 Gc/sec, of the phase velocity of the waves close to the surface of the upper layer, and the power variation with height above it, are described. A slow wave was found to propagate near the surface and its phase velocity was found to agree with that predicted theoretically for a TM surface wave. Qualitative agreement between the experimental and theoretical power variation with height confirmed the existence of a surface-wave contribution to the total field above such a layered dielectric system.
THE VISCOSITY OF LIQUID HELIUM II BETWEEN 0.79° K AND THE LAMBDA POINT
Authors: Woods A. D. B. , Hallett A. C. Hollis
Published: April 2011

Values of the viscosity of the normal component of liquid helium II have been determined using the rotating cylinder (Couette type) viscometer. Primary attention has been given to the temperature range between 0.79° K and 1.1° K; values at higher temperatures have been determined to provide a check on previous determinations. The results over the whole temperature range are closely fitted by an equation of the form given by Khalatnikov (Uspekhi Fiz. Nauk, 59, 673 (1956)).
REIGNITION OF FREELY RECOVERING SPARK CHANNELS IN HYDROGEN
Authors: Churchill R. J.
Published: April 2011

The paper describes an experimental technique and apparatus for the measurement of spark gap reignition in freely recovering spark channels in hydrogen. A unidirectional 235-ka current pulse produces the initial discharge while subsequent reignition is effected by a voltage generator whose output approximates a step-function over 50 μsec. Recovery characteristics are given for 16-mm-diameter tungsten rod electrodes in hydrogen at pressures ranging from 200 to 760 mm Hg, for 4-mm-diameter tungsten rods, and for 16- and 76-mm-diameter copper electrodes at 760 mm Hg. Gap length was varied from 1 to 5 mm. Study of the parameters shows that electrode size has the most pronounced effect on the recovery process.The deionization and recovery mechanisms are predicted theoretically and verified during the final recovery period where reignition by spark breakdown is observed. Gas temperatures derived from the recovery results are in good agreement with measured values.
THE ALPHA DECAY OF EVEN–EVEN NUCLEI
Authors: Steenberg N. R. , Sharma R. C.
Published: April 2011

The distribution of alpha particles on the surface of even–even alpha-emitting nuclei has been calculated by an approximate method initiated by V. G. Nosov and resembling Fröman's. Good agreement was obtained with the result of inward integration.
THE DERIVATION OF THE NONLINEAR ELASTIC EQUATIONS FROM A CRYSTAL MODEL
Authors: Grindlay J.
Published: April 2011

If a homogeneous static stress is applied to a finite crystal whose internal energy is a function only of the position co-ordinates of the atoms, then the applied stress tensor satisfies the macroscopic nonlinear elastic equations.
THE REACTION D(p, γ)He3 BELOW 50 KEV
Authors: Griffiths G. M. , Lal M. , Scarfe C. D.
Published: April 2011

The yield and angular distribution of the γ rays from the reaction D(p, γ) He3 have been measured with thick heavy-ice targets in the energy range from 24 kev to 48 kev. Assuming a simplified energy dependence the results have been analyzed to give cross sections for p-wave and s-wave capture. At 25 kev in the laboratory system, the cross sections are[Formula: see text]The astrophysical S-factors in the center-of-mass system below 40 kev have been found to be[Formula: see text]for E in center-of-mass kilovolts and[Formula: see text]independent of energy giving a total S-factor for low energies[Formula: see text]with E in center-of-mass kilovolts.
A NEW ESTIMATE OF THE DENSITY AND INTENSITY OF EXTRAGALACTIC RADIO SOURCES
Authors: Harrower G. A. , Watson M. J.
Published: April 2011

The recent availability, through a statistical analysis of the Cambridge measurements of cosmic radio sources, of a source-count curve extended to distances at which the effect of recessional velocity is clearly evident in the measurements, has prompted the following comparison of this measured source-count curve with a theoretical curve based on a steady-state analysis. A best fit of measurements and theory allows values of proper density of sources ρ0 and intensity factor b to be estimated independently. The results obtained are ρ0 = 35 × 10−74 sources per cubic meter and b = 11 × 1025 (MKS units).
FACE-CENTERED CUBIC COBALT-RICH SOLID SOLUTIONS IN BINARY ALLOYS WITH ALUMINUM, GALLIUM, SILICON, GERMANIUM, AND TIN
Authors: Luo Huey-Lin , Duwez Pol
Published: April 2011

By rapidly cooling liquid alloys, single-phase face-centered cubic cobalt-rich solid solutions have been obtained with up to 17.2 at.% aluminum, 18.2 at.% gallium, 13 at.% silicon, 17.4 at.% germanium, and 5 at.% tin. With the exception of silicon, these limits of solubility exceed those found under equilibrium conditions. The variation of lattice parameter with composition has been measured and the data can be fitted with straight lines for all solute elements except gallium, in which a change of slope is observed at 13.2 at.%.
YIELDS AND ANGULAR DISTRIBUTIONS OF FAST PHOTOPROTONS
Authors: Mitchell O. M. Mracek , McNeill K. G.
Published: April 2011

Measurements are described on the angular distributions of fast photoprotons (Ep > 8 Mev) ejected from 16 elements of [Formula: see text] by a bremsstrahlung spectrum of 22-Mev maximum energy. Some shell features are observed which, together with results of other authors, are discussed in terms of the Wilkinson model of photodisintegration.
DIFFRACTION BY A CONDUCTING CIRCULAR CYLINDER CLAD BY AN ANISOTROPIC PLASMA SHEATH
Authors: Ohba Yujiro
Published: April 2011

Diffraction of cylindrical waves by a conducting cylinder clad by an anisotropic plasma is treated. Both electric and magnetic current filaments are considered as sources. The filament source may be located either inside or outside of the plasma region. A radiation pattern is computed for the magnetic current source located on the conducting cylinder parallel to the cylinder axis. The beam from such a radiator is sharper than that in the isotropic case and it is deflected by the static magnetic field which is applied to the plasma region.
RELATIONSHIP BETWEEN THE REAL AND IDEAL RESISTIVITY OF PLATINUM
Authors: Berry R. J.
Published: April 2011

The relationship between the real and ideal resistance functions (RT/R273) has been examined for a wide variety of specimens of thermometric platinum over the range 0–900° K. An attempt was made to relate these two functions by using Matthiessen's rule in addition to Kohler's theoretical expression for the deviation from Matthiessen's rule. It was found that Kohler's relation did not apply for most specimens of thermometric platinum; however, in the restricted range 20–90° K, it appeared to hold fairly well for about 17 of the 65 resistors examined.Values for the ideal resistance function have been determined by extrapolating the measured resistance values of a large number of platinum resistance thermometers. In the range 10–90° K a special method of extrapolation has been used which appears to give greater accuracy than previously attained. Also, methods for estimating the residual resistance ratio (at 0° K) from measurements at higher temperatures are discussed.The results of this investigation have been applied to the practical problem of extending the present platinum resistance temperature scale below 90.19° K. To this end, a somewhat different method for interpolating the real resistance function between a number of fixed calibration temperatures has been outlined and compared with earlier methods.
BIPOLAR THEORY OF METAL–SEMICONDUCTOR CONTACTS UNDER ARBITRARY INJECTION LEVELS
Authors: Horita R. E. , Burgess R. E.
Published: April 2011

Metal–semiconductor contacts have been known empirically to obey a modified diode equation I = Is (exp qV/akT −1), where the parameter a often took values greater than the theoretical limit of two. Previous theories could not simply account for this anomaly. The model presented in this paper considers one-dimensional bipolar flow of carriers with zero recombination in a homogeneous semiconductor filament with a rectifying and an ohmic contact at opposite ends. The zero-electron-current theory by Borneman et al. (1955), valid for low injection levels, is extended to arbitrary injection levels by the use of the Misawa junction relations (1955). Then the nonzero-electron-current theory is developed. This theory shows that a is unity for low injection into extrinsic semiconductors and that a = (3b − M)/(b − M) for arbitrary injection into intrinsic semiconductors and for high injection into extrinsic semiconductors; M is the electron-to-hole current ratio and b is the electron-to-hole mobility ratio. Thus a can take any value depending on the magnitude of M/b.
A STUDY OF THE Be9(He3, n)C11 REACTION
Authors: Zwan L. van der , Stewart A. T. , Park J. Y. , Merzbacher E.
Published: April 2011

The energy spectra and angular distributions of the emergent neutrons from the Be9(He3, n)C11 reaction have been obtained for an incident He3-particle energy of 2 Mev with the technique of observing proton recoil in photographic emulsions. The cross sections were normalized to Be9(He3, p)B11 data observed simultaneously at 90° to the beam. The lack of similarity in the (He3, n) and (He3, p) mirror reactions to some residual states suggests a direct interaction mechanism rather than compound nucleus. An attempt to analyze some of the data in terms of double particle stripping has been made.
THE LOW-TEMPERATURE RESISTIVITIES AND THERMOPOWERS OF α-PHASE COPPER–ZINC ALLOYS
Authors: Henry W. G. , Schroeder P. A.
Published: April 2011

The thermopowers and resistivities of α-phase copper–zinc alloys have been measured between 4.2° and 300° K. A phonon-drag contribution to the thermopower exists for all zinc concentrations. It initially decreases in magnitude, as the zinc concentration increases, but above 10 at.% it begins to increase. This is attributed to the approach of the Fermi surface to the {200} faces of the Brillouin zone. The characteristic temperature θR is derived from the resistivity results and correlated empirically with the position of the phonon-drag maximum. The thermopower, for concentrations greater than 10 at.%, is very sensitive to the thermal history of the alloy.
ON THE HARMONIC RESPONSE OF SOME NONLINEAR SYSTEMS
Authors: Makow D. M. , Hurd R. A.
Published: April 2011

The harmonic components and the describing function for several types of nonlinear characteristics are calculated. The nonlinear effects take the form of threshold, curvature, saturation, negative slope, and infinite slope in various combinations. Both antisymmetrical and asymmetrical characteristics are considered. Two kinds of sinusoidal excitation are dealt with: (a) operating point at the origin, signal amplitude unrestricted; (b) operating point not at the origin, amplitude smaller than the bias.The calculations are based on approximating the actual characteristic by the product of a linear and a squared exponential function. As examples of the method, approximations to the tunnel diode characteristic and to a system with threshold and saturation were made using this function.
RANGE OF Xe133 AND Ar41 IONS OF KEV ENERGIES IN TUNGSTEN
Authors: McCargo M. , Davies J. A. , Brown F.
Published: April 2011

An accurate electrochemical technique for the removal of extremely thin (10–1000 Å) uniform layers of metal from a tungsten target has been developed analogous to that used previously for range studies in aluminum. This technique has been used to obtain the range distributions of Xe133 and Ar41 ions in rolled tungsten foils as a function of energy over the region 2–200 kev approximately. The distributions consist of an asymmetric peak followed by a point of inflection and a very penetrating "tail". Unlike the earlier distributions in aluminum, the "tail" in tungsten is exponential only over a limited region; it eventually decreases in an approximately Gaussian manner. Comparison with theory shows that in tungsten the median range is about a factor of two larger than that predicted by the Lindhard theory.A range distribution has also been obtained for 40-kev Kr85 ions in amorphous WO3. This distribution shows no penetrating "tail", a result which is in accordance with recent computer studies by Robinson and Oen (1963), who suggest that the "tails" observed in crystalline (metallic) targets are due to channeling of the incoming ions by the crystal lattice. Also, in WO3, the median range is in reasonable agreement with theory.
SPECTRAL OBSERVATIONS ON A RADIO-FREQUENCY EXCITED NITROGEN JET
Authors: Pleiter D.
Published: April 2011

A spectroscopic survey has been made over the wavelength range of 3000 Å to 9000 Å of the light from various regions of a jet of excited nitrogen flowing into an evacuated chamber. The jet of nitrogen, which was excited by a high-frequency transmitter, formed a nodular or beadlike flow pattern. Bands of the Goldstein–Kaplan, Gaydon green, and Herman infrared systems were observed in a flow boundary which surrounded a sharply defined cylindrical surface, presumably a high-density shock region.
THE COBALT RESONANCE CAPTURE INTEGRAL
Authors: Eastwood T. A. , Werner R. D.
Published: April 2011

The resonance integral of cobalt has been measured by comparison of the cadmium ratios for gold and cobalt in 1/E slowing-down spectra in two thermal reactors. The value obtained was 69.9 barns, for a cadmium cutoff of 0.5 ev, with the 1/v part included. The error, including uncertainties in the thermal neutron cross sections for cobalt and gold and the resonance integral for gold as well as the experimental error, is estimated to be ±3.5 barns. The reduced resonance integral, i.e. after subtraction of the 1/v part, is 53.1 ± 3.5 barns, and the s√(T0/T) value in the Westcott nomenclature is 1.60±0.08.
THE EFFECTS OF PRESSURE ON THE PARAMAGNETIC–ANTIFERROMAGNETIC TRANSITION OF DYSPROSIUM
Authors: Landry Peter , Stevenson Richard
Published: April 2011

The shift of temperature with pressure of the paramagnetic–antiferromagnetic phase transition of dysprosium at 177° K has been found to be −(0.55±0.02) × 10−3 deg K/(kg/cm2). Pressure was applied to the substance by compressing the metal between two pistons in a cylinder. The transition point was determined by measuring the magnetic moment of the sample as a function of temperature at various pressures up to 8400 kg/cm2. The results appear to be consistent with current theories of the magnetic properties of dysprosium.
ZEEMAN EFFECT ANALYSIS OF THE NEUTRAL SPECTRUM OF LUTETIUM
Authors: Pinnington E. H.
Published: April 2011

Results are presented for the Zeeman effect obtained in a field of 27,000 gauss for 40 lines due to Lu 1. These lines were excited in an electrodeless discharge in lutetium iodide activated by 2450-Mc/s microwave radiation. The assignment of spectroscopic terms to energy levels in Lu 1 is discussed, the Zeeman effect data being used to identify six new terms and to confirm nine others, and a summary is presented of all similar pertinent data.The presence of a relatively large hyperfine structure in some of the Lu lines investigated has been found to cause marked deviations in the resultant Zeeman patterns from that to be expected on the basis of L–S coupling. These deviations are discussed and compared with what may be expected when appreciable A-and B-h.f.s. splitting factors are involved.
A WAVE-GUIDE METHOD OF MEASUREMENT OF THE DIELECTRIC CONSTANT OF LOW-LOSS LIQUIDS
Authors: Dagg I. R. , Reesor G. E.
Published: April 2011

A method of measurement of the real and imaginary parts of the dielectric constant of low-loss liquids is described. The real part of the dielectric constant is derived from the impedance change at an air–dielectric interface in a wave guide; the imaginary part is derived from attenuation measurements made on a liquid-filled guide. The results of initial measurements on carbon tetrachloride and heptane in the frequency range 8.2 to 12.4 Gc/s are given.
ELECTRICAL IMPEDANCE OF ELECTRODES IMMERSED IN MOVING PLASMA
Authors: Smy P. R.
Published: April 2011

The electrical impedance of two cold electrodes immersed in moving argon plasma has been measured. The plasma is formed by a shock wave moving at 4–8 × 105 cm/sec into argon at an initial pressure of 0.01–1 mm Hg. It is found that a pronounced discontinuity in electrode impedance exists under all experimental conditions at electrode voltages in the neighborhood of 50 volts. An appreciable capacitance, which is dependent both on electrode area and on plasma density, is detected in the electrode impedance with electrode voltages of less than about 50 volts. This is ascribed to displacement currents in a sheath at the surface of one or both electrodes. Values of sheath thickness calculated from the observed "capacities" show order-of-magnitude agreement with the calculated plasma Debye length. Since the sheath electric fields corresponding to an electrode voltage of 50 volts and these sheath thicknesses are in the range 106–108 volts/cm, it is thought that the observed impedance discontinuity arises from the onset of electron emission from the cathode.
ELECTRICAL AND OPTICAL STUDIES OF THE ARGON PLASMA JET
Authors: Watson M. D. , Ferguson H. I. S. , Nicholls R. W.
Published: April 2011

A preliminary study has been made of the physical processes occurring in an argon plasma jet flowing at Mach 2.5. Axial electron and ion temperatures and densities were measured as functions of distance along the jet, using spectroscopic and electrical probe techniques. Estimates were also made of the degree of ionization, the electron–ion recombination coefficient, and the ambipolar diffusion coefficient. It was found that electron temperatures (~4000° K) were about twice as large as the effective rotational temperatures of N2 molecules (~1500° K) and thus of ion temperatures. Electron densities were ~1012 cm−3. The degree of ionization was ~6 × 10−4. The dominant mechanism for deionization was found to be dissociative recombination (between electrons and A2+ ions) over the first 8 cm of the jet, after which ambipolar diffusion appeared to become important.
THE DECANTED INTERFACE
Authors: Hunt M. D. , Spittle J. A. , Smith R. W.
Published: April 2011

Dilute tin, lead, and bismuth alloy crystals have been grown horizontally under conditions which gave rise to a cellular substructure and their decanted interfaces have been examined. From the results, it is concluded that the liquid film remaining after the decanting will only replicate those structural details of the original solid–liquid interface which are large and widely spaced compared with the thickness of the film. If the liquid undergoes a contraction on freezing, it may also reveal the presence of relatively deep and narrow depressions.
ROTATIONAL CONSTANTS AND ELECTRIC DIPOLE MOMENT OF NaF
Authors: Bauer R. K. , Lew H.
Published: April 2011

Transitions between the J = 0 and J = 1 rotational levels of Na23F19 have been measured by the molecular beam electric resonance method in the three lowest vibrational states. The following rotational constants have been determined (all frequencies in Mc/sec):[Formula: see text]The Na quadrupole interaction constants in the J = 1 level are:[Formula: see text]The spin-rotation interaction constant for Na in the J = 1 level for ν = 0, 1, and 2 is[Formula: see text]The equilibrium internuclear distance computed directly from Be is[Formula: see text]The electric dipole moment is:[Formula: see text]
DIELECTRIC THEORY OF PLASMA OSCILLATIONS AND ITS EXTENSION TO THE EXCITON PROBLEM
Authors: Horie C.
Published: April 2011

A new form of the microscopic expression for the dielectric constant is derived and used to obtain the dispersion relation for plasma modes. It is found that the usual dispersion relation for plasma modes derived using the random phase approximation contains higher-order correlation effects than is usually believed. The dielectric approach to the plasma problem is extended to the exciton problem by introducing a nonlocal charge density instead of the local charge density appearing in the case of the plasma modes. The same equation determining the energy of the exciton states as derived in a previous paper is obtained.
A PRECISION IRON-FREE π√2 BETA-RAY SPECTROMETER OF 35-CM OPTIC CIRCLE RADIUS
Authors: Wolfson J. L. , King W. J. , Park J. J. H.
Published: April 2011

An air-core high-resolving-power, high-luminosity double-focusing spectrometer of the high-aperture type is described. Focusing up to the fourth order in the axial departure angle is achieved with the use of three pairs of magnet coils. A compact coil structure was devised which enables electrons of up to 2.5 Mev in energy to be focused without undue rise in conductor temperature, thus preserving the feature of high precision in the measurement of relative electron momenta. For point sources the instrument is designed to achieve resolutions of 0.01%, 0.1%, and 1.0% in momentum, at transmission values of 0.08%, 0.38%, and 1.2% respectively. The use of a curved exit slit enhances the luminosity of the instrument by permitting the use of long sources.The narrowest experimental line width attained has been 0.014% in momentum at half the maximum intensity, at a transmission of 0.06% and using a source 0.1 mm in width.
METASTABLE Ar+ IONS NEAR THE Ar++ THRESHOLD
Authors: McGowan J. Wm. , Kerwin Larkin
Published: April 2011

When applied to the mass spectrum of argon, the techniques of Aston banding and I.P. curve comparison reveal the presence of metastable states of Ar+ near the ionization threshold of Ar++. These metastable states make possible the collision charge-exchange reaction 10/20 with an over-all cross section at 1 kev of a least 2.5 Å2.
DELAYED IMPLOSION OF THE Z-PINCH IN NITROGEN
Authors: Curzon F. L. , Hodgson R. T. , Churchill R. J.
Published: April 2011

The paper presents the first photographic evidence of the delayed implosion of the Z-pinch in nitrogen at pressures in excess of 375 μ Hg. Two implosions are observed before the discharge column is compressed to its minimum diameter. The time interval between the two implosions is found to increase linearly with pressure.The radius of the discharge column as a function of time is measured with a framing camera and is also calculated from the electrical characteristics of the discharge. By comparing the computed and measured values of the radius of the discharge column at given pressures, it has been shown that the second implosion does not arise from a transfer of the discharge current into material near the walls of the discharge vessel, in contrast to results commonly observed in very energetic discharges.
INTRINSIC LOSS AT THE EDGES OF ANISOTROPIC PLASMAS
Authors: Hurd R. A.
Published: April 2011

The electromagnetic field near the edge where three sectors meet is investigated. The three sectors are composed of anisotropic plasma, perfect conductor, and isotropic material. With the static magnetic field parallel to the edge, it is found that intrinsic loss occurs at the edge when the frequency lies in a certain range. The loss is found to be closely related to degenerate surface waves at the plasma–metal interface. The conditions under which these waves can exist are investigated. Comparisons are made with the ferrite case which was investigated previously.
ON THE ANOMALOUS SELF-DIFFUSION IN BODY-CENTERED CUBIC ZIRCONIUM
Authors: Kidson G. V.
Published: April 2011

Results of recent diffusion studies in the BCC phase of Zr give unusually low values of the parameters Q and D0 in the expression for the diffusion coefficient D = D0 exp(−Q/RT). Measurements in the high-temperature range show a marked departure from linearity in a plot of log D vs. 1/T. A simple model is proposed to account for these results based on the assumption that excess vacancies introduced by impurities (probably oxygen) predominate in the low-temperature region. It is found that for zirconium the measured diffusion coefficient can be represented over the whole temperature range by D = 1.34 exp (−65,200/RT) + 8.5 × 10−5 exp (−27,700/RT) cm2/sec. The calculated concentration of excess vacancies is 0.038 atomic per cent.
STUDY OF A PROPOSAL FOR DETERMINING THE g-FACTOR ANOMALY FOR ELECTRONS BY RESONANCE EXCITATION IN A MAGNETIC FIELD
Authors: Byrne J.
Published: April 2011

Following recent proposals for the experimental determination of the electron g-factor anomaly, a study has been made of the properties required of a perturbing electromagnetic field for the production of particular transitions between the states of an electron moving in a constant homogeneous magnetic field. The matrix elements have been calculated for the transitions of interest and some suggestions have been advanced for the solution of certain experimental problems indicated by the results of the study.
CANALISATION D'ONDES ÉLECTROMAGNÉTIQUES PAR DIFFRACTION ITÉRÉE
Authors: Boivin Germain , Tremblay Réal
Published: April 2011

The determination of a state of steady wave propagation through a periodic sequence of lenses with minimal beam power loss is based on a previously published study of encircled energy in the visible region. The amplitude function T(x) derived from an extremum of the factor of encircled energy E(W) for a fixed abscissa W = Wm = 5 can be replaced with sufficient accuracy by the varied function [Formula: see text]; the periodic sequence of lenses illuminated by a field distribution [Formula: see text] is analogous to a low-loss beam wave guide.With regard to this theoretical analysis and practical application, the authors describe the characteristics of a beam wave guide for millimeter waves which maintains an optimum compromise between diffraction losses and line dimensions. This analysis is completed by experimental results from a microwave beam wave guide operating at the 1.25 cm wavelength.
A QUANTITATIVE STUDY OF THE LIMITING POLARIZATION OF HIGH-FREQUENCY RADIO WAVES
Authors: Reddy C. Abhirama
Published: April 2011

A detailed numerical investigation of the characteristics of the "limiting region" in the ionosphere is carried out, using both Booker's criterion (1936) and Budden's equation (1952) for determining the "limiting region". The results show that, in the case of vertically downcoming high-frequency radio waves, the "limiting region" always occurs at levels of very low electron density for all conditions of normal layer propagation, thus justifying the method of computing the limiting polarization (from the Appleton–Hartree equation) with N = 0.The possibility that irregular ionization patches in the lowermost ionosphere might give rise to multiple "limiting levels" and thus affect the limiting polarization of downcoming radio waves is investigated; it is shown that such an effect, though theoretically possible, is not likely to occur frequently.
A NEW METHOD FOR MEASURING THE DEPTHS OF EMBEDDED RADIOTRACER ATOMS USING A PRECISION β-RAY SPECTROMETER
Authors: Graham R. L. , Brown F. , Davies J. A. , Pringle J. P. S.
Published: April 2011

A quantitative method has been developed for measuring the mean depth within a solid of those radioactive atoms which decay with the emission of monoenergetic conversion electrons. By acceleration to kev energies in a mass separator 16.8-hour Xe125 atoms were injected into metal foils, and the intense K 54.96 and K 188.4 conversion lines were then scanned in the Chalk River π√2 β-ray spectrometer. The manner in which these conversion line shapes varied with Xe125 depth was calibrated by covering the foil surfaces with known thicknesses of Al or Au; it was found that the peak heights decreased in an approximately exponential manner with increasing Xe125 depths. With this calibration, mean depths can be determined under unknown conditions; the maximum sensitivity is about 6 atom layers (15 Å) under the most favorable conditions. Examples are given of the application of the method to metal oxidation studies and to Xe125 range measurements.
LABORATORY SIMULATION OF THE SOLAR WIND MAGNETOSPHERE INTERACTION
Authors: Osborne F. J. F. , Shkarofsky I. P. , Gore J. V.
Published: April 2011

A controlled plasma–magnetic field interaction has been achieved, the conditions of which are such as to fulfill generally the scaling considerations of some aspects of geophysical phenomena, in particular the initial commencement of a magnetic storm. The preliminary measurements indicate the sweeping action on a magnetic field by a moving plasma; the formation of a magnetic cavity; the motion of the "dip pole" under perturbed conditions; the stand-off of plasma; a quasi Van Allen belt whose drift westward can be suggested as a ring current mechanism; and a polar trapping region. The correlations between the laboratory observations, geophysical measurements, and related theories, where possible, show no serious discrepancies as yet.
INCLUSION OF FLOW TERMS IN THE CARTESIAN TENSOR EXPANSION OF THE BOLTZMANN EQUATION
Authors: Shkarofsky I. P.
Published: April 2011

The Cartesian tensor expansion of Boltzmann's equation as given by Johnston (1960) is extended to include terms denoting gradients in flow velocity. The expansion is performed in intrinsic velocity space. The gradient velocity terms yield a linear contribution to the tensor (f2) part of the angle-integrated distribution function from which the zero-trace pressure tensor is calculable. It is shown that the standard moment equations are obtained by further integration over the magnitude of velocity. For the case of a completely ionized gas, collisional terms are inserted appropriately.
INFRARED ABSORPTION LINES IN BORON-DOPED SILICON
Authors: Colbow Konrad
Published: April 2011

In boron-doped silicon, optical absorption takes place through the excitation of bound holes from the ground state to excited states. This leads to a line spectrum. Because of a lack of sufficient resolution and a failure to make proper allowance for line distortion by the finite spectrometer slit width, previous authors gave a misleading picture of the low-temperature half-width, the temperature dependence of this half-width, and the onset of concentration broadening at low temperatures.New experimental data are presented and explained by introducing the mechanism of statistical Stark broadening due to ionized impurities, and by modifying Baltensperger's (1953) theory for concentration broadening. At low impurity concentration the width is attributed to phonon broadening (Barrie and Nishikawa 1963) and internal strains (Kohn 1957).
CONSISTENT MODEL FOR PbS PHOTODETECTORS: II. NEW MODEL
Authors: Giroux Guy
Published: April 2011

The experimental properties analyzed in Part I of this study are compared with a theoretical analysis of carrier recombination through multiple levels already published by the author. This suggests the possibility of a model of the number theory type. A trap for the electron carriers is located at 0.13 ev below the conduction band and a recombination level at 0.10 ev below the trap level. The Fermi and the recombination levels are coincident. The number of trapping centers is about 1018cm−3, and the number of recombination centers 2 × 1017cm−3. Almost all the experimental evidence used in support of both the barrier and the number theory can be verified by the new model, and the previous contradictions are removed. The behavior of the photodetector under various background illumination levels is also explained.
NUMERICAL SOLUTION OF THE HARTREE–FOCK EQUATIONS
Authors: Froese Charlotte
Published: April 2011

Procedures for solving the Hartree–Fock equations on an automatic computer such as the IBM 7090 are described. Particular attention is given to the question of numerical accuracy and to the problem of devising automatic procedures.
DIRAC'S COSMOLOGY AND RADIOACTIVE DATING
Authors: Kanasewich E. R. , Savage J. C.
Published: April 2011

It has long been recognized that Dirac's principle might imply that the rate of β decay would vary with the age of the universe. If so, the radioactive ages of meteorites and terrestrial rocks as indicated on the one hand by α decay and on the other by β decay should differ. However, the comparison of these ages is complicated by a large uncertainty in the decay constant for Rb87. Thus the age data must be analyzed to determine the decay constant most compatible with the particular theory of β decay which is used. Using this best decay constant for each theory, we find that the data are more consistent with a β decay rate independent of the age of the universe than with the dependence implied by the Dirac principle.
THE VISCOUS DAMPING OF ATMOSPHERIC GRAVITY WAVES
Authors: Pitteway M. L. V. , Hines C. O.
Published: April 2011

Dissipation produced by viscous damping and thermal conduction is important in the study of atmospheric gravity waves, which are themselves important in a study of "irregular" motions in the upper atmosphere. The mathematics of this damping is considered in some detail here, and charts are given to assess the effects of viscous damping and thermal conduction at meteor heights in the upper atmosphere. The results of this paper are consistent with the conclusions of an earlier analysis, insofar as the two overlap, and extend the range of conditions considered.
A ROCKET-BORNE ELECTRIC FIELD PROBE
Authors: Johnson D. W. , Kavadas A.
Published: April 2011

A description is given of an instrument developed to measure electric fields in and near auroral displays. The instrument is carried aloft in a rocket and ejected once the rocket is above the region where air drag is appreciable. During the free fall portion of the flight the instrument continuously measures the ambient electric field and telemeters this information to ground. The sensing element is a voltage-variable capacitor connected between two insulated portions of the container.
THE HEIGHT OF THE 5577-Å NIGHT AIRGLOW LAYER
Authors: Brandy J. H.
Published: April 2011

A statistical triangulation of the height of the 5577-Å night airglow has been carried out. A value of 95 ± 5 km has been obtained.
LORENZ NUMBERS OF PURE ALUMINUM, SILVER, AND GOLD AT LOW TEMPERATURES
Authors: Fenton E. W. , Rogers J. S. , Woods S. B.
Published: April 2011

Measurements have been made of the thermal and electrical conductivities at low temperatures on specimens of pure aluminum, silver, and gold. The resistivities caused by scattering of the electrons by lattice waves and by impurities have been separated and the Lorenz number has been deduced for these specimens. The Lorenz number calculated from the impurity resistivities for these pure metals agrees with the theoretical Sommerfeld value within an experimental error of about [Formula: see text]. The possible influence of an electron–electron interaction on these results is discussed.
THE NEAR-ULTRAVIOLET ABSORPTION SPECTRUM OF CS2
Authors: Kleman Bengt
Published: April 2011

A study has been made of high-resolution absorption spectra of C12S2 and C13S2 in the region 4300–3300 Å. The spectra are shown to arise from transitions from the ground state to two or more excited electronic states. In the lowest excited state the molecule is not linear, and the following constants have been derived for C12S232:[Formula: see text]There is some uncertainty as to the absolute values of v2, and this greatly influences the determination of v3 and v000. With the most probable numbering, v2 = 940 cm−1 and v000 = 26187 cm−1. From a study of the four isotopic species C12S232, C12S32S34, C13S232, and C13S32S34, it is found that, in addition to a stretching and bending force constant, two large interaction constants are needed to describe the force system. Data on the higher excited states are fragmentary. The species of the electronic states is still in doubt.
SOME AVERAGE PROPERTIES OF THE OUTER RADIATION ZONE AT 1000 KM
Authors: McDiarmid I. B. , Burrows J. R. , Budzinski E. E. , Wilson Margaret D.
Published: April 2011

The particle detectors in the Alouette satellite have been used to obtain time-averaged intensity distributions for the particles in the outer radiation zone at an altitude of 1000 km. Average intensities of protons in the energy range 1–7 Mev and electrons with energies greater than 40 kev, 250 kev, and 3.9 Mev have been obtained as a function of the invariant latitude, the particle pitch angle, and magnetic activity as determined by the Kp index. Some of the measurements are compared with ground-based measurements of auroral radio-absorption.
PRECISE KINETIC ENERGY MEASUREMENTS AND FINE STRUCTURE IN THE SPONTANEOUS FISSION OF Cf252
Authors: Fraser J. S. , Milton J. C. D. , Bowman H. R. , Thompson S. G.
Published: April 2011

The kinetic energies of the fragments from spontaneous fission of Cf252 have been remeasured in order to provide reliable data for the calibration of semiconductor detectors. The results, which are in satisfactory agreement with a recent measurement by Whetstone (1963), are presented in a convenient form for the energy calibration of semiconductor detectors by means of a least-squares fitting procedure. They are given before and after neutron emission. A fine structure is seen in the mass–energy contour diagram in the region of low fragment excitation energy. As in the slow-neutron-induced fission of lighter elements there are periodic yield maxima at heavy fragment mass numbers of 134, 140, 146, and 152.
HIGH-RESOLUTION RAMAN SPECTROSCOPY OF GASES: XVII. THE PURE ROTATIONAL RAMAN SPECTRUM OF IODOACETYLENE
Authors: Jones W. Jeremy , Stoicheff B. P. , Tyler J. K.
Published: April 2011

A study of the pure rotational Raman spectrum of iodoacetylene has yielded a value of 0.10622 cm−1 for the ground-state rotational constant. From this value, and from assumed C≡C and C—H bond lengths of 1.203 Å and 1.055 Å respectively, the C—I bond length is calculated to be 1.988 Å.
DESIGN OF TWO-REGION SOLENOIDS
Authors: Stevenson Richard
Published: April 2011

A two-region solenoid consists of an inner solenoid placed within the bore of a large outer solenoid. It is shown that a two-region solenoid can always be built which has a higher magnetic efficiency (lower power consumption) than a single solenoid producing the same field over the same volume. The two-region solenoid also gives an important reduction in the stress level. These advantages are expected to be decisive in the design of large high-field cryogenic magnets.
NONLINEAR PROPAGATION OF ELECTROMAGNETIC WAVES IN MAGNETOPLASMAS
Authors: Sodha Mahendra Singh , Palumbo Carl J.
Published: April 2011

In this communication the authors have derived an expression for the conductivity tensor of a Lorentzian plasma in the presence of a static magnetic field, which is correct to terms involving the square of the amplitude of the electric vector. This expression along with the wave equation has been used to obtain a second-order solution for the electric vector in the magnetoplasma. The phenomenon of demodulation of an amplitude-modulated wave has also been briefly discussed.
DIFFUSION IN MULTICOMPONENT METALLIC SYSTEMS: VI. SOME THERMODYNAMIC PROPERTIES OF THE D MATRIX AND THE CORRESPONDING SOLUTIONS OF THE DIFFUSION EQUATIONS
Authors: Kirkaldy J. S. , Weichert D. , Haq Zia-Ul-
Published: April 2011

The second law requirement that the Onsager L matrix for isothermal diffusion in a stable solution be positive definite and the stability condition for such a solution that the Hessian of the Gibb's free energy be positive definite impose on the diffusion D matrix the condition that it always have real and positive eigenvalues. This condition ensures that solutions of the differential equations for diffusion will always relax in a nonperiodic way.
THE ABSORPTION OF HIGH-ENERGY RADIATION, A MONTE CARLO STUDY: III. DENSITY AND TRANSPARENCY DISTRIBUTIONS
Authors: Steenberg N. R. , Crofts W. P.
Published: April 2011

Random spherical arrays of rigid spheres are being studied as a model for a nucleus under high-energy bombardment. This paper reports on the distribution of sphere centers, the matter distribution, and the transparency for such arrays. Low (12.5%) and high (42.2%) nominal densities are treated for arrays numbering 27 and 216 spheres. At high densities a strong surface correlation of geometric origin is observed. Analytic formulas are presented which in general adequately represent the Monte Carlo data.
AN ACTION PRINCIPLE FOR MAGNETOHYDRODYNAMICS
Authors: Calkin M. G.
Published: April 2011

The equations of motion of an inviscid, infinitely conducting fluid in an electromagnetic field are transformed into a form suitable for an action principle. An action principle from which these equations may be derived is found. The conservation laws follow from invariance properties of the action. The space–time invariances lead to the conservation of momentum, energy, angular momentum, and center of mass, while the gauge invariances lead to conservation of mass, a generalization of the Helmholtz vortex theorem of hydrodyanmics, and the conservation of the volume integrals of A∙B and v∙B, where A is the vector potential, B is the magnetic induction, and v is the fluid velocity.
ON THE STRUCTURAL, THERMAL, ELECTRICAL, AND MAGNETIC PROPERTIES OF AuSn
Authors: Jan J.-P. , Pearson W. B. , Kjekshus A. , Woods S. B.
Published: April 2011

The Au1−xSn phase has a homogeneity range within the limits 50.0 and 50.5 at.% Sn. The lattice constants and observed densities vary between the limits:[Formula: see text]The thermal conductivity, electrical resistivity, and absolute thermoelectric power of oriented single crystals of Au1−xSn have been measured between 2.5° K and room temperature. The results exhibit pronounced anisotropies. Measurements of the magnetic susceptibility between liquid air temperature and 650–750° K are also reported for three different Au1−xSn alloys.The various results are discussed, and some speculations are presented regarding the number of conduction electrons in AuSn.
RADIATION FROM AN AXIALLY SLOTTED CYLINDER WITH A RADIALLY INHOMOGENEOUS PLASMA COATING
Authors: Rusch W. V. T.
Published: April 2011

Radiation patterns have been computed for an axial slot on an infinite circular cylinder coated with a radially inhomogeneous plasma sheath. The relative dielectric constant was assumed to have three types of radial dependence: monotonic with a minimum at the inner edge of the sheath but with no portion of the sheath below plasma resonance; monotonic with the inner portion of the sheath below plasma resonance; parabolic with a minimum within the sheath and the inner portion of the sheath below resonance. The radial wave functions within the sheath are obtained in the form of infinite series. The resulting radiation patterns are found to be sharply directed in the forward direction relative to the equivalent free-space pattern. These sharply forward-directed patterns are consistent with the interpretation of a "diffusion-type" process within layers of the sheath below cutoff and a predominantly "refraction-type" process within layers above cutoff.
INFRARED SPECTRA OF NaF AND KF
Authors: Ritchie R. K. , Lew H.
Published: April 2011

The vibrational constants of NaF and KF, derived from their infrared spectra, are:[Formula: see text]The vibrational frequencies of RbF and CsF, obtained by extrapolation, are:[Formula: see text]The rotational constant Be and the internuclear distance of KF, previously obtained by molecular beam methods, have been revised slightly as a consequence of the new data.
DETERMINATION OF AN ABSOLUTE SCALE OF CAPACITANCE
Authors: Dunn A. F.
Published: April 2011

In the past decade or two, the measurement of capacitance has become of much greater importance in many fields of scientific and technological investigation as well as forming the basis of many production applications. The capabilities of the capacitance measuring techniques available are of great importance, and the measurement and maintenance of an absolute scale of capacitance has become of prime importance. In the National Research Council of Canada, the absolute unit of capacitance is now known with an accuracy better than ±0.0005%, with the capability of scaling the unit of capacitance over six decades of capacitance both above and below 1 pf (1 × 10−12 f) without introducing an additional indeterminacy any greater than ±0.0005% or ±0.3 af (af = attofarad = 10−18 f).
THE HUND GRAVITATIONAL EQUATIONS AND THE EXPANDING UNIVERSE
Authors: Chambers Ll. G.
Published: April 2011

A spherically symmetrical solution is found for the Hund gravitational equations. It is shown that this solution is not inconsistent with the known motion of nebulae.