Showing papers in "Canadian Journal of Physics in 1961"
TL;DR: In this article, the occurrence at high latitudes of a large number of geophysical phenomena, including geomagnetic agitation and bay disturbances, aurorae, and various irregular distri...
Abstract: This paper is concerned with the occurrence at high latitudes of a large number of geophysical phenomena, including geomagnetic agitation and bay disturbances, aurorae, and various irregular distri...
1,320 citations
TL;DR: In this paper, an expansion in powers of some parameter is needed in order to solve the master equation by a systematic approximation method, and the appropriate parameter is the reciprocal size of the system.
Abstract: In order to solve the master equation by a systematic approximation method, an expansion in powers of some parameter is needed. The appropriate parameter is the reciprocal size of the system, defin...
439 citations
TL;DR: Two general procedures for the measurement and analysis of angular correlations of gamma radiations from nuclear reactions are described in this article, which have wide applications in nuclear spectroscopy for the detection of nuclear reactions.
Abstract: Two general procedures for the measurement and analysis of angular correlations of gamma radiations from nuclear reactions are described which have wide applications in nuclear spectroscopy for the...
283 citations
TL;DR: In this article, the motions set up in a liquid due to the passage of a drop of an immiscible liquid have been examined for a number of liquid-liquid systems.
Abstract: The motions set up in a liquid due to the passage of a drop of an immiscible liquid have been examined for a number of liquid–liquid systems. Wake configurations corresponding to Reynolds numbers b...
192 citations
TL;DR: In this paper, a horizontal electric dipole which is located above or below the plane surface of a conducting half-space is considered, and expressions for the fields are obtained using three different ap...
Abstract: The problem considered is a horizontal electric dipole which is located above or below the plane surface of a conducting half-space. Expressions for the fields are obtained using three different ap...
178 citations
TL;DR: The theory of translational infrared absorption in gases was developed in this paper, where invariant expressions for the integrated absorption coefficients were derived and the absorption coefficients are expanded in powe...
Abstract: The theory of translational infrared absorption in gases is developed. Invariant expressions for the integrated absorption coefficients are derived. The absorption coefficients are expanded in powe...
137 citations
TL;DR: The boron flame bands have been observed in absorption during the flash photolysis of mixtures of Boron trichloride and oxygen and detailed analysis of the spectrum has shown that the bands arise from...
Abstract: The boron flame bands have been observed in absorption during the flash photolysis of mixtures of boron trichloride and oxygen. Detailed analysis of the spectrum has shown that the bands arise from...
123 citations
TL;DR: In this paper, the electronic conductivity for any degree of ionization, radio frequency, and d-c was evaluated for various electron speed power law variations of the electron speed.
Abstract: Values are presented for the electronic conductivity for any degree of ionization, radio frequency, and d-c. magnetic field strength, and various electron speed power law variations of the electron...
119 citations
TL;DR: In this paper, a theory was developed for the scattering of radio waves by the electron density fluctuations that exist in an ionized gas in thermal equilibrium, and the theory treated the theory with respect to radio frequency.
Abstract: In an earlier paper (Fejer 1960) a theory was developed for the scattering of radio waves by the electron density fluctuations that exist in an ionized gas in thermal equilibrium. The theory treate...
106 citations
TL;DR: In this article, the absolute transition probability for the (b −a) system was found to be 2.5 × 10−3 −1sec−1 with an uncertainty of a factor of 2.
Abstract: The Q branch of the (0,0) band of the electric quadrupole transition in O2 has been observed at 1.908 μ in the emission spectrum of a discharge through O2 and He. By a comparison with the (0,0) atmospheric O2 band , the absolute transition probability for the (b–a) system has been found to be 2.5 × 10−3 sec−1, with an uncertainty of a factor of 2. The (0,0) band of the infrared atmospheric system of O2 has also been observed in emission. Using the observed intensity of the (0,1) atmospheric O2 band in the aurora and airglow one may predict that the (0,0) (b–a) band should be detectable in a strong aurora if observations are made from high altitude.
106 citations
TL;DR: The Raman spectrum of hydrogen as a pure gas and in mixtures with helium and argon was studied in the pressure range 100 to 2000 atmospheres at room temperature.
Abstract: The Raman spectrum of hydrogen as a pure gas and in mixtures with helium and argon was studied in the pressure range 100 to 2000 atmospheres at room temperature. Frequency shifts and half-widths of...
TL;DR: In this article, it was shown that the temporary distortion of a previously stable belt of energetic charged particles, trapped in the earth's magnetic field, results in a system of ionospheric currents and magnetospheric motions.
Abstract: It is shown that the temporary distortion of a previously stable belt of energetic charged particles, trapped in the earth's magnetic field, results in a system of ionospheric currents and magnetospheric motions. The currents are caused by the charge separation which occurs in the course of the subsequent adiabatic motion of the energetic particles. The resulting current system closely resembles the well known Ds current system. The polarization fields, which drive these currents, give rise to magnetospheric motions similar to those of Axford and Hines and the implications of their work then also result. The distortion of the belt could be caused either directly, by the introduction of a new group of trapped particles mainly on the day side of the magnetosphere, or indirectly, through the relatively sudden compression of the earth's field on the day side, caused by the arrival of a neutral stream of charged particles from the sun.
TL;DR: In this article, 12 bands of HNO and 18 bands of DNO in the region 6,000 to 10,000 A have been photographed in emission during the reactions of hydrogen and deuterium atoms with nitric oxide.
Abstract: Twelve bands of HNO and 18 bands of DNO in the region 6,000 to 10,000 A have been photographed in emission during the reactions of hydrogen and deuterium atoms with nitric oxide. Two of the HNO bands and 3 of the DNO bands show a sharp breaking-off in the K-rotational structure, due to predissociation of the molecule in the excited state. Upper limits for the dissociation energies of HNO and DNO are 48.6 kcal/mole and 49.1 kcal/mole respectively.
TL;DR: In this article, the progression of ammonia bands which extends from 1689 to 1400 A has been photographed in absorption at high resolution and six bands have been analyzed and found to be of the perpendicular type.
Abstract: The progression of ammonia bands which extends from 1689 to 1400 A has been photographed in absorption at high resolution. Six bands have been analyzed and found to be of the perpendicular type. Th...
TL;DR: In this paper, the correlation functions of the matrix elements between different spin states of the interaction coupling were used to calculate the nuclear spin-lattice relaxation times T 1 in liquids and gases.
Abstract: Calculation of nuclear spin–lattice relaxation times T1 in liquids and gases involves the correlation functions of the matrix elements between different spin states of the interaction coupling the ...
TL;DR: In this article, the problem of growth of instabilities (fingers) in displacement processes in porous media is analyzed from a statistical viewpoint, where the relative area occupied by fingers is represented as a "satur...
Abstract: The problem of growth of instabilities (fingers) in displacement processes in porous media is analyzed from a statistical viewpoint. The relative area occupied by fingers is represented as a "satur...
TL;DR: In this paper, the eigenvalue equation for the velocity and the formulae for the components of the displacement and energy-flow vectors are summarized, and the velocities of propagation, directions of displacement and directions of energy flow for the three waves have been calculated for many orientations of the wave normal.
Abstract: In non-isotropic single crystals the normals to the wavefronts of elastic waves are not colinear with the vectors representing either the energy flow or the particle displacement. Calculations have been carried out on the propagation characteristics of sound waves in two particular trigonal crystals, α-quartz and sapphire.The development of the eigenvalue equation for the velocity and the formulae for the components of the displacement and energy-flow vectors are summarized. The assumption that the wave has a plane wavefront normal to a given direction leads to three solutions, one representing a quasi-longitudinal wave and the other two representing quasi-transverse waves. The velocities of propagation, directions of displacement, and directions of energy flow for the three waves have been calculated for many orientations of the wave normal. Detailed results for propagation near one of the pure-mode axes are presented.
TL;DR: In this article, the T(α,γ)Li7 reaction was observed using thin targets of tritium absorbed in zirconium bombarded by singly charged helium ions of energy from 0.5 to 1.9
Abstract: The T(α,γ)Li7 reaction has been observed using thin targets of tritium absorbed in zirconium bombarded by singly charged helium ions of energy from 0.5 Mev to 1.9 Mev. The cross section rises smoothly with energy in a fashion characteristic of a direct radiative capture process. The ratio of the intensities of transitions to the first excited state at 478 kev and to the ground state is 0.40 ± 0.05. The angular distribution is, to within errors, isotropic at Eα = 0.8 Mev but is significantly higher at 0° than at 90° for Eα = 1.6 Mev. The total capture cross section at a mean alpha-particle energy in the target of 1.32 Mev is 3.58 ± 0.60 microbarns and the corresponding astrophysical S factor is 0.064 ± 0.016 kev barn in the center of mass system. The results are compared with recent theoretical results on the direct radiative capture process.
TL;DR: In this paper, self-diffusion coefficients of crystal-bar zirconium have been measured between 1500 °C and 1100 °C, using radioactive Zr95 as a tracer.
Abstract: Self-diffusion coefficients of crystal-bar zirconium have been measured between 1500 °C and 1100 °C, using radioactive Zr95 as a tracer. The results may be represented byThe pre-exponential factor ...
TL;DR: In this article, the (2.0) bands of the A2Σ+−X2Π system of SH and SD have been photographed for the first time.
Abstract: The (2,0) bands of the A2Σ+−X2Π system of SH and SD have been photographed for the first time. More accurate values for the vibrational constants of the A2Σ+ state have been obtained. The dissociation energy of SH in the excited state is from which it is possible to deduce that the ground state dissociation energy (SH) is 28,480 ± 1000 cm−1 (81.4 ± 2.9 kcal/mole, 3.53 ± 0.12 ev).
TL;DR: A rocket experiment to study the charged particles associated with auroral radio absorption is described in this paper, where a primary electron flux, probably in the form of beams or columns, with a maximum intensity of 2'×'106 particles cm−2 sec−1 sterad−1 was observed.
Abstract: A rocket experiment to study the charged particles associated with auroral radio absorption is described. A primary electron flux, probably in the form of beams or columns, with a maximum intensity of 2 × 106 particles cm−2 sec−1 was observed. The integral electron energy spectrum could be represented by exp (−E/22 kev) at energies above 30 kev. The angular distribution of the incident electrons was approximately isotropic over the upper hemisphere. Two other types of angular distributions, involving large intensities of upward-moving particles, were observed. The measured electron flux was sufficient to account for the observed radio absorption.Protons in the energy range greater than 500 kev were recorded with a maximum intensity of 6 × 102 particles cm−2 sec−1 sterad−1. The proton intensity was relatively steady and was not correlated with the electron flux either in space or in time. Most of the protons appeared to enter the atmosphere to the south of Fort Churchill.
TL;DR: In this article, the authors investigated the pressure pulse produced by a large explosion in the atmosphere and represented the explosion in terms of the excess pressure and normal velocity on a closed surface.
Abstract: The pressure pulse produced by a large explosion in the atmosphere is investigated. The explosion is represented in terms of the excess pressure and normal velocity on a closed surface, outside of ...
TL;DR: In this article, the 1.63-Mev gamma ray following the 3.34-mev unobserved gamma ray from the 4.97mev state in Ne/sup 20/ was found to disagree with theory.
Abstract: Angular correlation of the 1.63-Mev gamma ray following the 3.34-Mev unobserved gamma ray from the 4.97-Mev state in Ne/sup 20/ was found to disagree with theory (Litherland, A. E., and Ferguson, A. J., Can. J. Phys. 39, 788(1961)). An explanation is given. (L.N.N.)
TL;DR: A rotational analysis of the 2780-A emission band obtained in a microwave discharge through CCl4 vapor and photographed on a 20-ft grating spectrograph showed that a 2Δi(b)
Abstract: A rotational analysis of the 2780 A emission band obtained in a microwave discharge through CCl4 vapor and photographed on a 20-ft grating spectrograph shows that a 2Δi(b) → 2Πr(a) transition of the CCl radical is responsible, not 2Σ → 2Π(a) as reported by previous workers. Molecular constants are given for the combining states, as well as a vibrational analysis that identifies the 2780 A band as the (0–0) band.
TL;DR: In this article, the dielectric behavior of several ferroelectric ceramic materials when a two-dimensional stress was applied normal to the axis of polarization was studied and it has been shown that the...
Abstract: Studies have been made of the dielectric behavior of several ferroelectric ceramic materials when a two-dimensional stress was applied normal to the axis of polarization. It has been shown that the...
TL;DR: The temperature of the superconducting transition has been measured for high purity lead samples from three different sources as discussed by the authors, and the transition temperature for all samples agreed to within 0.001° and
Abstract: The temperature of the superconducting transition has been measured for high purity lead samples from three different sources. The transition temperature for all samples agreed to within 0.001° and...
TL;DR: In this paper, it was shown that the most favorable distribution of radiant energy in a diffraction pattern is that which corresponds to the best concentration around the center O. This hypothesis is expressed by an extremal condition on the factor of encircled energy E(W), that is, the ratio of the energy inside a circle of radius W and centered on the diffraction patterns, to the total energy in the same.
Abstract: It is recognized that the most favorable distribution of radiant energy in a diffraction pattern is that which corresponds to the best concentration around the center O. This hypothesis is expressed by an extremal condition on the factor of encircled energy E(W), that is, the ratio of the energy inside a circle of radius W and centered on the diffraction pattern, to the total energy in the same.A study of the effects of spherical aberration on this factor of encircled energy has shown that aberration always tends to decrease the factor from the value obtained with an Airy pattern. However, this factor may be increased by the use of an amplitude filter at the pupil of the optical system.In treating the case of amplitude filters one may use a rigorous analysis in terms of Taylor's series in (1−x2)p−1 or a polynomial Tn(x) of degree n−1 in terms of (1−x2).The corresponding amplitudes in the diffraction pattern are Г(W) and Гn(W); the maximum factor of encircled energy E(Wm) and En(Wm). The following converge...