Showing papers in "Canadian Journal of Physics in 1968"
TL;DR: In this article, an efficient method for computing the best straight line by least squares when there are statistical errors in both coordinates is given, and exact expressions for the variances of the slo...
Abstract: An efficient method is given for computing the best straight line by least squares when there are statistical errors in both coordinates. Exact expressions are obtained for the variances of the slo...
527 citations
TL;DR: In this paper, fast, light ions (e.g. protons and α particles) in crystals containing displaced atoms are discussed on the basis of Lindhard's theory, with the particular purpose of applying channeli...
Abstract: Channeling of fast, light ions (e.g. protons and α particles) in crystals containing displaced atoms is discussed on the basis of Lindhard's theory, with the particular purpose of applying channeli...
341 citations
TL;DR: In this paper, the orientation dependence of the backscattered yield of 1.0-MeV helium ions has been used to investigate the lattice characteristics of silicon and germanium implanted at room temperature with 40-...
Abstract: The orientation dependence of the backscattered yield of 1.0-MeV helium ions has been used to investigate the lattice characteristics of silicon and germanium implanted at room temperature with 40-...
255 citations
TL;DR: In this article, the channeling of ions with through thin (0.24-1.5 μ) silicon samples has been studied for ion energies ranging from about 100 keV to 500 V.
Abstract: The channeling of ions with through thin (0.24-1.5 μ) silicon samples has been studied for ion energies ranging from about 100 keV to 500 keV. The effects of radiation damage and sample misorientat...
174 citations
TL;DR: The absorption spectrum of SiH2 in the visible region has been photographed at high dispersion and the rotational structure of three bands has been analyzed in the lower electronic state 1A1.
Abstract: The absorption spectrum of SiH2 in the visible region has been photographed at high dispersion and the rotational structure of three bands has been analyzed. In the lower electronic state 1A1 the H...
157 citations
TL;DR: In this paper, the angular behavior of the sputtering ratio for Ar+ on (100) Cu turned around a [011] axis was studied for energies of 5, 10, 15, 20, and 35 V.
Abstract: Measurements of the angular behavior of the sputtering ratio for Ar+ on (100) Cu turned around a [011] axis are presented for Ar+ energies of 5, 10, 15, 20, and 35 keV. It is shown that the widths ...
145 citations
TL;DR: In this article, the rotational analysis showed conclusively that the molecule responsible is a diatomic molecule containing two carbon nuclei, a conclusion that was further confirmed by the observation of the corresponding system using 13CH4 instead of 12CH4.
Abstract: A new system of very simple Σ–Σ bands in the region 4800–6000 A has been observed in flash discharges in CH4, both in absorption and emission. The rotational analysis shows conclusively that the molecule responsible is a diatomic molecule containing two carbon nuclei, a conclusion that is further confirmed by the observation of the corresponding system using 13CH4 instead of 12CH4. Neither the upper nor the lower state is one of the known states of C2. None of the predicted low-lying states of C2 fits the observed new states. Two possibilities remain: either the new system corresponds to two fairly highly excited levels of C2 or it is due to the C2− ion. The latter alternative finds some support in the similarity of the new system to the near ultraviolet bands of N2+ (which has the same number of electrons). However, the doublet splitting required by this interpretation has not been resolved, nor has the study of perturbations in the upper state given clear-cut evidence for doublet structure. On the other...
138 citations
TL;DR: In this article, a generalized pair of space-correlation and wave-number spectrum functions, which has properties indicated by fluid dynamics and by intuition, is proposed, in contrast with previously used comb...
Abstract: A new generalized pair of space-correlation and wave-number spectrum functions, which has properties indicated by fluid dynamics and by intuition, is proposed. In contrast with previously used comb...
130 citations
TL;DR: A simple derivation using group theory is given of the spherical harmonic expression for the most general multipole interaction between two charge distributions in this article, and simplifications in the general expression which result when the charge distributions are of symmetrical shape are discussed.
Abstract: A simple derivation using group theory is given of the spherical harmonic expression for the most general multipole interaction between two charge distributions. Simplifications in the general expression which result when the charge distributions are of symmetrical shape are discussed.
124 citations
TL;DR: The hydrodynamic origin of cosmic rays (Colgate and Johnson 1960) depends upon the shock ejection of the outer layers of the supernova as discussed by the authors, where the increase in energy of the shock to c2 per gram occurs relatively deep within the star where the fraction of mass external to this layer is 10−4.
Abstract: The hydrodynamic origin of cosmic rays (Colgate and Johnson 1960) depends upon the shock ejection of the outer layers of the supernova. The increase in energy of the shock to c2 per gram occurs relatively deep within the star where the fraction, F, of mass external to this layer is 10−4. The relativistic shock wave continues to increase in strength in the decreasing density of the envelope. When the shock "breaks through" the surface denned as one Compton scattering mean free path at radius R, then the energy factor . The temperature in the proper frame of the shock is determined by the condition aT4 = 2γs2ρ0, where ρ0 is the initial rest density ahead of the shock. For a typical presupernova star, , and polytrope of index 3, the temperature becomes (1.7–2) × 105 eV at the surface layer. Photons emitted from the moving surface layer will be Doppler-shifted from their mean proper frame value of 3kT to a final energy .Photons originating in, and emitted from, the surface layer before the layer expands adiab...
120 citations
TL;DR: In this paper, the intensities of rotational lines in 3Σ-1Σ electronic transitions of linear molecules were investigated, allowing for the effects of spin-spin interaction.
Abstract: Formulae are given for the intensities of rotational lines in 3Σ–1Σ electronic transitions of linear molecules, allowing for the effects of spin–spin interaction. For transitions an error in the re...
TL;DR: In this paper, it was shown that the dip observed in the Q branch of the pressure-induced vibrational spectra at high densities is an interference effect due to the correlations existing between the dipole moments induced in successive binary collisions.
Abstract: The dip observed in the Q branch of the pressure-induced vibrational spectra at high densities is shown to be an interference effect due to the correlations existing between the dipole moments induced in successive binary collisions. A similar dip is predicted to exist in the translational spectra of inertgas mixtures at zero frequency. This intercollisional interference effect has the same origin as the dip in the spectral density of the intermolecular force, discussed by Purcell in connection with nuclear electric dipole relaxation. The effect does not occur for the anisotropic part of the induced dipole moments, and this explains the observed absence of any splitting of the S lines and of the QQ component of the Q branch of the induced infrared spectra.
TL;DR: In this paper, the concentration profiles of 32P ions implanted into silicon crystals have been studied over the energy range 10 −110 kV using an electromagnetic separator, where the beam directions near the major channel were studied.
Abstract: Concentration profiles of 32P ions implanted into silicon crystals have been studied over the energy range 10–110 keV, using an electromagnetic separator. Beam directions near the major channeling ...
TL;DR: The scattering of Ar, Ne, and He ions from the Cu {100} face has been investigated by a digital computer technique; only binary elastic collisions of ions with the lattice atoms have been considere...
Abstract: The scattering of Ar, Ne, and He ions from the Cu {100} face has been investigated by a digital computer technique; only binary elastic collisions of ions with the lattice atoms have been considere...
TL;DR: In this paper, data obtained from the Alouette II satellite are used to examine various high-latitude boundaries of the outer radiation zone as a function of local magnetic time.
Abstract: Data obtained from the Alouette II satellite are used to examine various high-latitude boundaries of the outer radiation zone as a function of local magnetic time. Four different boundaries are defined and these are referred to as the 35-keV "background" boundary, the 35-keV "smooth" boundary, the 35-keV "sharp" boundary, and the 3.9-MeV "background" boundary. All of the boundaries show a marked dependence on local magnetic time. The 35-keV "smooth" and the 3.9-MeV "background" boundaries are identified with the stable trapping region and show a 1100–2300-hour asymmetry of about 3°. The 35-keV "background" boundary falls at higher latitudes than the other boundaries at all local times; a noon–midnight asymmetry of about 6° is observed as well as a marked dawn–dusk asymmetry. The 35-keV "background" boundary is tentatively associated with the boundary of closed geomagnetic field lines and it is suggested that there is a dawn–dusk asymmetry in the field configuration. The 35-keV "sharp" boundary is identifi...
TL;DR: In this paper, the authors studied the interplanetary magnetic field radial gradients between 0.81 and 1.0 AU noting microstructure, mesostructure, macrostructure and directional distribution of discontinuities.
Abstract: Interplanetary magnetic field radial gradients between 0.81 and 1.0 AU noting microstructure, mesostructure, macrostructure and directional distribution of discontinuities
TL;DR: In this paper, the mean squared torque due to anisotropic multipolar, induction and dispersion interactions has been calculated for the CH4-N2 and CH4−N2 systems.
Abstract: Extensive measurements of the methane ν3 and ν4 fundamental vibration–rotation bands in CH4–He mixtures and the ν3 band in CH4–He, CH4–N2, and CD4–He mixtures have been carried out in infrared absorption at 295 °K to pressures of 3000 atm. Some profiles of the ν3 band in CH4–Ar mixtures and in pure CH4 have also been obtained. Rotational correlation functions, band moments, and intermolecular mean squared torques have been determined from the ν3 band profiles. Theoretical calculations of the mean squared torque due to anisotropic multipolar, induction and dispersion interactions have been carried out. The theoretical and experimental torques are in order-of-magnitude agreement for the CH4–N2 and CH4–CH4 systems; for CH4–He, CD4–He, and CH4–Ar the theoretical values are two to three orders of magnitude too small to account for the experimental values, indicating that in these cases the dominant contribution to the torques is given by the anisotropic overlap forces.
TL;DR: In this paper, an inverse power-law approximation for the interaction potential between a fast-moving projectile and the atoms of an amorphous target into which it penetrates was proposed.
Abstract: By using an inverse power-law approximation for the interaction potential between a fast-moving projectile and the atoms of an amorphous target into which it penetrates, it is possible to calculate...
TL;DR: The cross section for the muon bremsstrahlung process is calculated as a function of the nuclear form factor in the Born approximation following the Bethe and Heitler theory as mentioned in this paper.
Abstract: The cross section for the muon bremsstrahlung process is calculated as a function of the nuclear form factor in the Born approximation following the Bethe and Heitler theory. The influence of the n...
TL;DR: Sputtering efficiency is defined in this article as the fraction of bombarding ion energy leaving a crystal via sputtering and backscattering, and is defined for the case of perpendicular incidence on a crystal.
Abstract: Sputtering efficiency is denned as the fraction of bombarding ion energy leaving a crystal via sputtering and backscattering. This quantity is calculated for the case of perpendicular incidence on ...
TL;DR: In this paper, the width of the rotational Raman lines of H2 was studied in the region of density from 1 to 100 amagats at room temperature, and collisional narrowing and broadening of the lines were observed with a minimum in the width occurring near a density of 10 amagiats.
Abstract: The width of the rotational Raman lines of H2 was studied in the region of density from 1 to 100 amagats at room temperature. Collisional narrowing and collisional broadening of the lines is observed with a minimum in the width of the lines occurring near a density of 10 amagats. A comparison of the width of the S0(0) and S0(1) lines indicates that collisions which produce the broadening and the collisions which produce the narrowing are uncorrelated. The observations are only qualitatively in agreement with the theory of the width of the lines.
TL;DR: The optical emission spectrum of the BH radical produced in a discharge tube designed to give high electric fields shows Stark effects as discussed by the authors, and the dipole moments of the X(1Σ+) and A(1 Π) states are obtained from these.
Abstract: The optical emission spectrum of the BH radical produced in a discharge tube designed to give high electric fields shows Stark effects. From these, the dipole moments of the X(1Σ+) and A(1Π) states...
TL;DR: In this paper, two new band systems of the NH+ molecule have been photographed at high dispersion and analyzed, one consisting of a single band at 4348.5 A and the second consisting of three bands of a 2Σ−−2Π transition with the strongest (0−0) band lying at 4628.9 A.
Abstract: Two new band systems of the NH+ molecule have been photographed at high dispersion and analyzed. One system consists of a single band at 4348.5 A which arises from a 2Δ–2Π transition and the second consists of three bands of a 2Σ−–2Π transition with the strongest (0–0) band lying at 4628.9 A. A number of the vibrational and rotational constants of these states have been determined. From a study of the isotopic species 14NH+, 15NH+, and 14ND, it has been established that the ground state of NH+ is the 2Π state and that a 4Σ− state lies 354 cm−1 higher. The spectrum has allowed us to determine the wavelengths at which cometary spectra and interstellar absorption lines of NH+ are expected to fall and to predict that the transition between the two lowest levels, which may be of interest to radio astronomy, occurs at 13 500 mc/s.
TL;DR: Hall effect and resistivity measurements from room temperature to 4.2 °K have been carried out on silicon samples implanted with 400-keV phosphorus, lithium, and boron ions as discussed by the authors.
Abstract: Hall effect and resistivity measurements from room temperature to 4.2 °K have been carried out on silicon samples implanted with 400-keV phosphorus, lithium, and boron ions. Implantations were carr...
TL;DR: In this paper, the emission yield from single crystals doped with β emitters was investigated and it was shown that energetic electrons emitted from a lattice position show a peak in yield up to 2.4 times the no...
Abstract: The emission yield from single crystals doped with β emitters is investigated. In the axis direction, energetic electrons emitted from a lattice position show a peak in yield up to 2.4 times the no...
TL;DR: The theory of nuclear quadrupole spin-lattice relaxation in anharmonic crystals was developed in this article, both in terms of ordinary perturbation theory and in the terms of phonon Green functions.
Abstract: The theory of nuclear quadrupole spin–lattice relaxation in anharmonic crystals is developed, both in terms of ordinary perturbation theory and in terms of phonon Green functions. The important relaxation processes are shown to be the direct, first-order Raman, and anharmonic Raman (aR) processes. The aR process is a second-order process due to a combination of the linear spin–lattice coupling and the cubic anharmonic lattice forces, and can be interpreted as arising from the second-order self-energy term in the single-phonon Green function. The effect on the relaxation of the higher-order phonon self-energy and lifetime effects is investigated and shown to be of minor importance. A new method of treating polarization mixing in the Dyson equation for the phonon Green functions is presented. The theory is applied to nuclear quadrupole relaxation in alkali halide crystals and the aR process is shown to be dominant. Nuclear electric dipole and electron paramagnetic relaxation are also discussed.
TL;DR: In this paper, the excitations of cobalt fluoride have been studied with the technique of slow-neutron inelastic scattering using a triple-axis crystal spectrometer.
Abstract: The excitations of cobalt fluoride have been studied with the technique of slow-neutron inelastic scattering. A triple-axis crystal spectrometer was used throughout in its constant Q mode of operat...
TL;DR: In this article, vertical cutoff rigidities have been calculated for a world grid 5 degrees in latitude and 15 degrees in longitude using the Finch and Leaton sixth-degree simulation of the quiescent geomagnetic field.
Abstract: Vertical cutoff rigidities have been calculated for a world grid 5 degrees in latitude and 15 degrees in longitude using the Finch and Leaton sixth-degree simulation of the quiescent geomagnetic field. These calculations utilized the trajectory-tracing procedure at intervals of 0.01 BV throughout the penumbral region to determine an "effective" vertical cutoff rigidity defined by Shea et al. (1965). When experimental cosmic-ray intensity data are plotted using threshold rigidities derived from this grid, greater coherence of these data is found than is obtained using previously published threshold values. However, small deviations from an intuitively pleasing smooth curve indicate we may have reached a limitation in the usefulness of vertical cutoff rigidities, and perhaps second-order effects should be included when using cutoff rigidity as a parameter in the analysis of very precise cosmic-radiation intensity data.
TL;DR: In this article, a computer program is developed which follows the trajectories of fast ions in crystals, based on the assumption of classical dynamics and binary collisions, and it can be used to calculate the velocity of a fast ion in a crystal.
Abstract: A computer program has been developed which follows the trajectories of fast ions in crystals, based on the assumption of classical dynamics and binary collisions. Initial work has been directed at...
TL;DR: A review of radiation damage and diffusion phenomena in a large variety of ionic crystals (oxides and halides) and two metals following ion bombardment is given in this paper, where both light and heavy ion beams are used.
Abstract: A review is given of radiation damage and diffusion phenomena in a large variety of ionic crystals (oxides and halides) and two metals following ion bombardment. Ion beams of both light and heavy n...