Showing papers in "Canadian Journal of Physics in 1960"
TL;DR: In this paper, the proper interpretation of irregular motions in the upper atmosphere has been investigated by a variety of techniques, but their proper interpretation has yet to be established. But their proper meaning has not yet been established.
Abstract: Irregularities and irregular motions in the upper atmosphere have been detected and studied by a variety of techniques during recent years, but their proper interpretation has yet to be established...
1,886 citations
TL;DR: In this article, a cylindrical electrostatic electron selector is described which provides a 10−7 ampere beam of electrons whose energy may be varied from 0 to 50'ev and whose energy spread is less than 100'mv.
Abstract: A cylindrical electrostatic electron selector is described which provides a 10−7 ampere beam of electrons whose energy may be varied from 0 to 50 ev and whose energy spread is less than 100 mv. Spa...
163 citations
TL;DR: In this article, the infrared fundamental band of liquid and solid hydrogen was investigated over a range of para-concentrations from 25% to 100% with a prism spectrometer and, in part, with a grating Spectrometer.
Abstract: The infrared fundamental band of liquid and solid hydrogen was investigated over a range of para-concentrations from 25% to 100% with a prism spectrometer and, in part, with a grating spectrometer
154 citations
TL;DR: In this article, a theory for the scattering of radio waves by density fluctuations which exist in an ionized gas in thermal equilibrium was developed for the frequency power spectrum of the scattered radio waves.
Abstract: A theory is developed for the scattering of radio waves by density fluctuations which exist in an ionized gas in thermal equilibrium.Expressions for the frequency power spectrum of the scattered wa...
148 citations
TL;DR: The specific heat of commercially pure cold-rolled copper and of annealed and heavily cold-worked 99.999% pure copper have been measured in the temperature range 20° to 300 deg;K.
Abstract: The specific heats of commercially pure cold-rolled copper and of annealed and heavily cold-worked 99.999% pure copper have been measured in the temperature range 20° to 300 deg;K. When results are...
86 citations
TL;DR: In this article, the rotational spectra of gaseous Zn(CH3)2, Cd(CH 3), Hg(CH), and fully deuterated molecules have been photographed with a 21-ft grating.
Abstract: The pure rotational spectra of gaseous Zn(CH3)2, Cd(CH3)2, Hg(CH3)2, and of the fully deuterated molecules have been photographed with a 21-ft grating. The spectra are typical of symmetric top molecules and consist of many evenly spaced rotational lines having a separation of about 0.45 cm−1. An analysis of the spectra yielded the rotational constants (in cm−1)From these constants the following metal—carbon bond lengths were determined: Zn—C = 1.929 A, Cd—C = 2.112 A, and Hg—C = 2.094 A. Relations for the C—H bond lengths and HCH angles were also obtained.
75 citations
TL;DR: A series of red-degraded absorption bands has been observed between 2650 and 3200 A and is attributed to a 2Π-2Π transition of the NCO radical as discussed by the authors.
Abstract: A series of red-degraded absorption bands has been observed between 2650 A and 3200 A and is attributed to a 2Π-2Π transition of the NCO radical. The bands probably represent a progression of the upper-state stretching vibration . The rotational structure of one band has been analyzed. Diffuseness in some of the bands indicates predissociation of the upper state, and is discussed in terms of the dissociation energy of NCO.
72 citations
TL;DR: A simple formula based on the work of Klein and Rees was developed for calculating potential energy curves, except near the dissociation limit, for electronic states of diatomic molecul.
Abstract: A simple formula, based originally on the work of Klein and Rees, is developed for calculating potential energy curves, except near the dissociation limit, for electronic states of diatomic molecul...
69 citations
TL;DR: In this paper, the rotational and vibrational energy bands in solid hydrogen, developed previously, are applied to the interpretation of the infrared and Raman spectra of solid parahydrogen.
Abstract: The theory of the rotational and vibrational energy bands in solid hydrogen, developed previously, is applied to the interpretation of the infrared and Raman spectra of solid parahydrogen. A comparison of the theory with the experimental results yields information about the nature of the rotational and vibrational motions of the molecules in the solid, and about the anisotropic intermolecular forces. A calculation of the intensity of the infrared rotational and vibrational lines is given, which is based on the induction mechanisms introduced previously to explain the induced absorption in gaseous hydrogen. Satisfactory agreement with the experimental values is obtained. The importance of the interaction between other than nearest neighboring molecules, and of the interference effects affecting the single transitions, is pointed out. A frequency analysis is given of the infrared and Raman rotational and vibrational lines in the solid, and a consistent theory of the shifts and splittings of the various line...
61 citations
TL;DR: In this paper, a theory of the temperature dependence of the shape of paramagnetic resonance lines is developed for temperatures sufficiently low to make the effects of the spin-lattice interaction and thermal ex...
Abstract: A theory of the temperature dependence of the shape of paramagnetic resonance lines is developed for temperatures sufficiently low to make the effects of the spin–lattice interaction and thermal ex...
56 citations
TL;DR: In this article, the rotational constants of HD were determined from a PbS infrared grating spectrometer and the 3-0 and 4-0 rotation-vibration bands were photographed with a 21-ft concave GRating spectrograph.
Abstract: The 1–0, 2–0, and 3–0 rotation–vibration bands of HD have been observed with a PbS infrared grating spectrometer and the 3–0 and 4–0 bands have been photographed with a 21-ft concave grating spectrograph. From these spectra precise values of the vibrational and rotational constants of HD in its electronic ground state have been determined. The variation of Bv and ΔG with v is similar to that recently established for H2, that is, the values for v = 0 and 1 are markedly above the values corresponding to a linear extrapolation of the subsequent points. This leads to an uncertainty in the ωe and Be values which is much greater than that of the ΔG and Bv values. The (very low) intensity of the rotation–vibration spectrum of HD is in close agreement with that predicted. The decrease of intensity in going from 1–0 to 4–0 is strikingly slow, far slower than in a normal series of fundamental and overtone bands. This also is in qualitative agreement with theoretical expectation for a molecule like HD which does not...
TL;DR: In this paper, a reproducibility of better than ± 0.15% of the magnetic susceptibility balance of copper, silver, and gold from 295° to 295° was described.
Abstract: A magnetic susceptibility balance is described which has a reproducibility of better than ±0.15%. The temperature dependence of the magnetic susceptibility of copper, silver, and gold from 295° to ...
TL;DR: In this article, an apparatus is described which detects γ-rays emitted by a thin target placed in a well-denned neutron beam, from which the ratio of the resonance integral to the 2200m/s cross section for radiative neutron capture in Pu-240 has been deduced, using Au as a reference standard.
Abstract: An apparatus is described which detects γ-rays emitted by a thin target placed in a well-denned neutron beam. It has been used to determine the Cd ratios of Au and Pu-240, from which the ratio of the resonance integral to the 2200 m/s cross section for radiative neutron capture in Pu-240 has been deduced, using Au as a reference standard. Using this ratio and previously measured values of the resonance integral of Pu-240 and its effective cross section in two positions in the NRX reactor, three separate estimates of the 2200 m/s cross section of Pu-240 have been made. The mean value is 270 ± 17 barns.In an auxiliary experiment to indicate the shape of the epithermal spectrum of the neutron beam, the activation Cd ratios of Mn and In were compared with that of Au. These results, combined with the known 2200 m/s capture cross sections of these nuclides, yield new values of the radiative capture resonance integrals for both Mn and In.
TL;DR: In this article, the cracks were observed to form in a hexagonal symmetry with respect to the grain boundaries and to the direction of the stress, and the rate at which these cracks formed decreased very markedly as the creep rate approached a constant value.
Abstract: Observations were made at one temperature on the cracks that form in ice during creep under constant compressive load. The ice had a hexagonal symmetry with respect to the grain boundaries. The load was applied perpendicular to the long axis of the grains. A piezoelectric crystal was used to detect the cracking activity in the ice.Two stages of cracking were observed. The first occurred during the transient period of the creep, and the plane of these cracks tends to be parallel to the grain boundaries and to the direction of the stress. The rate at which these cracks formed decreased very markedly as the creep rate approached a constant value. Above a certain stress, the creep rate continuously increased with time. Under this condition the second stage of cracking was observed. These cracks tend to be more irregular in direction and to occur in planes that are at 45° to the applied stress.
TL;DR: In this paper, the Raman spectrum of CH4 was obtained with a spectral resolution of 0.3 cm−1, and rotational analyses of the ν and ν2 bands were carried out.
Abstract: The Raman spectrum of CH4 was obtained with a spectral resolution of ~0.3 cm−1, and rotational analyses of the ν and ν2 bands were carried out. The B0 values obtained from the ν2 and ν3 bands are 5...
TL;DR: The time distribution of positron annihilations in the metals aluminum, lithium, sodium, potassium, and cesium have been measured with a fast time-to-amplitude converter.
Abstract: The time distribution of positron annihilations in the metals aluminum, lithium, sodium, potassium, and cesium have been measured with a fast time-to-amplitude converter. The decay curves appear to be complex, with about 5% of the events having a mean life of approximately 5×10−10 sec. The main (95%) components of the decay curves show the following mean lives, in units of 10−10 sec: Al, 1.9 ± 0.2; Li, 2.9 ± 0.2; Na, 3.15 ± 0.2; K, 4.0 ± 0.2; Cs, 4.3 ± 0.2. The results for the alkali metals disagree with the previously published measurements of De Benedetti and Richings (1952). These results are discussed, and the lifetimes for other metals are predicted roughly from them and from the angular correlation measurements of other workers.
TL;DR: In this paper, the resonance frequency of the Cl35 nuclear quadrupole in KClO3 has been measured as a function of temperature in the range 15 deg;K to 77 deg,K.
Abstract: The resonant frequency of the Cl35 nuclear quadrupole in KClO3 has been measured as a function of temperature in the range 15 deg;K to 77 deg;K; previous work between 77 deg;K and room temperature has been confirmed. Comparison has been made with Bayer's theory based on lattice vibrations and agreement is excellent. The ratio of the quadrupole coupling constant eQqzz of the two isotopes (Cl35 and CI37) has been measured at room and liquid air temperatures; significant changes have been observed in the measurements. Finally the possibility of using this temperature dependence as the basis of a sensitive thermometer has been studied; the accuracy of such a thermometer would be ±0.005 deg;K at 60 deg;K and ±0.05 deg;K at 20 deg;K.
TL;DR: The absolute abundances of the isotopes of fissionproduct xenon and krypton in six uranium minerals have been determined mass spectrometrically using the isotope dilution technique as mentioned in this paper.
Abstract: The absolute abundances of the isotopes of fission-product xenon and krypton in six uranium minerals have been determined mass spectrometrically using the isotope dilution technique. The fission pr...
TL;DR: In this paper, the shape of the oscillator potential for a systsm of single fermions in an anisotropic oscillator with Nilsson spin-orbit coupling is calculated.
Abstract: The shape of the oscillator potential necessary to give the minimum energy for a systsm of single fermions in an anisotropic oscillator with Nilsson spin-orbit coupling is calculated. The number of particles is limited to 50 or less and is even. The preferred distortion parameters ( beta and gamma ) are plotted vs. number of particles, and energy maps (energy vs. beta ) are given for various amounts of spin-orbit coupling. Implications of the calculations, e.g., that the Bohr strong coupling approximation and the Davydov- Filippov model cannot easily be justified, are discussed. (D.L.C.)
TL;DR: Coleman, Gaydon, and Vaidya as discussed by the authors used a 21ft concave grating spectrograph to photograph the methyl iodide flanle bands, lying in the region 4100 to 6300 a, and confirmed the assignment of the bands to the I0 molecule.
Abstract: The "methyl iodide flanle bands", lying in the region 4100 to 6300 a, have been photographed using a 21-ft concave grating spectrograph. The bands are shown to arise from an A211 + X211 transition of the I0 molecule. Rotational and vibrational analysis of the bands has been carried out and the molecular constants of I0 obtained. ISTRODUCTION A number of red-degraded bands, now ICIIOWII as the "methyl iodide flame bands", was first observed bl. Vaidya (1937) in emission from a flame of methyl iodide mixed with ~nethyl alcohol or coal gas. The bands were a~~alyzed into two systems, A and B, and were tentatively assignecl to the I0 or CI molecule. Coleman, Gaydon, and Vaidya (1948) obtained the bands in e~nission from all oxyhydrogen flame to which iodine was added, thus supporting the assignment to 10. These authors observed approximately 40 bands in the region 4100 to 6300 A and showed that all the bands could be arranged into one system instead of t~vo. Vibrational constants were given but no rotational analysis was attempted since the balds were observed only ~vith low resolution. Durie ancl Ramsay (1958) observed six bands of the same system in absorption cluring the flash photolysis of mixtures of iodine vapor and oxygen. The bands were observed with high resolution but no rotational analysis of the absorption bands was attempted since the same bancls, extencling to much higher J values, were also observed in emission from an oxyhyclrogen fla~ne to which methyl iodide was added. AlIost of the bands reported by Coleman, Gaydon, ancl Vaiclya were rephotographed under high resolution by Durie and Iiamsay. The rotational and vibrational analysis of these bands forms the main subject of the present paper and confirms the assignment of the bands to the I0 molecule. The source ~~sed to excite the methyl iodide flame bands consisted of a diffusion flame of hydrogen, saturated with methyl iodide vapor at room temperature, burning in an atmosphere of oxygen. The bands were photographed using the second order of a 21-ft concave grating spectrograph ancl Eastman I
TL;DR: In this article, the rotational and vibrational intensity distribution of the 0-0 first negative band was analyzed and the results were shown to be consistent with a fluorescent excitation process in which the rotation and vibration degrees of freedom of the ions come into radiative equilibrium with the solar radiation.
Abstract: Spectra of sunlit auroral rays were obtained from Saskatoon during the auroras of September 3/4 and 4/5, 1958. The resolution of these spectra was sufficiently high to enable measurements to be made of the relative intensities of the lines of the 0–0 first negative band as well as the relative intensities of bands of the Δυ = −1 sequence of this system. An analysis of the rotational line intensities shows they are consistent with an excitation process in which ions in thermal equilibrium with the atmosphere at 2200 °K fluoresce under the influence of solar radiation. The vibrational intensity distribution also is consistent with a fluorescent excitation from a state of thermal equilibrium at about 2050 °K. It is shown that the results are not consistent with a fluorescent excitation process in which the rotational and vibrational degrees of freedom of the ions come into radiative equilibrium with the solar radiation. Earlier conclusions that radiative equilibrium did hold for vibration are shown to be in ...
TL;DR: In this article, the reaction N14(γ,n)N13 has been studied by irradiating dicyandiamide in the X-ray beam of a 25-Mev betatron and measuring the residual activity with a sodium iodide crystal system.
Abstract: The reaction N14(γ,n)N13 has been studied by irradiating dicyandiamide in the X-ray beam of a 25-Mev betatron and measuring the residual activity with a sodium iodide crystal system. The photoneutr...
TL;DR: Most of the low-temperature thermoelectric behavior of annealed and cold-worked silver and gold samples can be accounted for satisfactorily by using Kohler's equation, S = ΣWiSi/ΣWi as discussed by the authors.
Abstract: Most of the low-temperature thermoelectric behavior of annealed and cold-worked silver and gold samples can be accounted for satisfactorily by using Kohler's equation, S = ΣWiSi/ΣWi, to calculate as a function of temperature the diffusion thermoelectricity under the influence of various competing scattering mechanisms in the metals, and by taking account of the phonon-drag contribution to the thermoelectricity. New data are presented and interpreted.
TL;DR: In this article, it was shown that the Goldstein equation for turbulent diffusion implies diffusion currents dependent upon the history of the concentration gradient, and that the hereditary function, by which the history is weighted, is the ensemble autocorrelation function of velocity.
Abstract: It is shown that the Goldstein equation for turbulent diffusion implies diffusion currents dependent upon the history of the concentration gradient. An analysis of the stochastic model upon which the Goldstein equation is based reveals that the hereditary function, by which the history is weighted, is the ensemble autocorrelation function of velocity. Heuristic arguments and an appeal to the theory of irreversible thermodynamic processes lead to the postulation of an integro-differential equation for turbulent diffusion involving the velocity autocorrelations of the diffusate particles.
TL;DR: Extensive thermal analyses have been made on 10 samples (suppliers' analyzed impurity contents <0.2 to <100 p.p.m.) of high purity tin, including zone-refined metal; liquidus points have been inter...
Abstract: Extensive thermal analyses have been made on 10 samples (suppliers' analyzed impurity contents <0.2 to <100 p.p.m.) of high purity tin, including zone-refined metal; liquidus points have been inter...
TL;DR: In this article, a study has been made of the macroscopic structure of the liquid-solid interface which exists during growth of silicon crystals by the Czochralski method.
Abstract: A study has been made of the macroscopic structure of the liquid–solid interface which exists during growth of silicon crystals by the Czochralski method. In two crystals the interface was seen to contain a (111) facet. The development of such facets is discussed with reference to current crystal growth theories.
TL;DR: In this article, the authors considered the two-dimensional problem of diffraction of a plane wave by a narrow slit, where the assumed boundary values on the screen are the vanishing of either the total wave function or its normal derivative.
Abstract: The two-dimensional problem of diffraction of a plane wave by a narrow slit is considered. The assumed boundary values on the screen are the vanishing of either the total wave function or its normal derivative. In the former case, a differential–integral equation is obtained for the unknown function in the slit; in the latter, a pure integral equation is found. Solutions to these equations are given in the form of series in powers of e (where e/π is the ratio of slit width to wavelength), the coefficients of which depend on log e. Expressions are found for the transmission coefficients as functions of e and the angle of incidence; these are compared with previous determinations of other authors.A brief outline is given for the treatment of diffraction of a cylindrical wave by the slit.
TL;DR: For the scalar diffraction of a plane wave by a prolate spheroid, the exact solution is known, and by expanding this in ascending powers of ka, where k is the wave number and 2a is th...
Abstract: For the scalar problem of the diffraction of a plane wave by a prolate spheroid the exact solution is known, and by expanding this in ascending powers of ka, where k is the wave number and 2a is th...