Showing papers by "Atomic Energy of Canada Limited published in 1969"
TL;DR: In this article, the equilibrium shapes of inert gas bubbles in zinc were determined by annealing foils which had been supersaturated with argon by ion bombardment, and the anisotropy of solid-vapour surface free energ...
Abstract: The equilibrium shapes of inert gas bubbles in zinc were determined by annealing foils which had been supersaturated with argon by ion bombardment. The anisotropy of solid-vapour surface free energ...
53 citations
TL;DR: In this article, a semi-empirical method was given to obtain the relative full-energy peak efficiency ϵγ of a Ge(Li) diode over the γ-ray energy range 50 to 1400 keV.
46 citations
TL;DR: In this paper, a floating-zone refined and pulled Si crystals doped with 1015 B atoms/cm3 were quenched from 800 to 1150°C into liquid nitrogen or water.
Abstract: Floating-zone refined and pulled Si crystals doped with 1015 B atoms/cm3 were quenched from 800 to 1150°C into liquid nitrogen or water. As many as 1015 donors/cm3 were created by both types of quench. No evidence was obtained, either from electrical conductivity or from photoconductivity measurements, that single vacancies, divacancies, or vacancy-oxygen pairs were retained by the quenches. Approximately 50% of the quenched-in defects annealed out near 300°K with a migration energy of (0.81 ± 0.04) eV. An energy level 0.4 eV from the top of the valence band was associated with these defects.
Zonengeschmolzene und Czochralski Si-Kristalle, welche mit 1015 B-Atomen/cm3 dotiert worden waren, wurden von 800 bis 1150°C in flussigem Stickstoff oder in Wasser abgeschreckt. 1015 Donatoren/cm3 wurden durch beide Abschreckarten erzeugt. Weder durch Messungen der elektrischen Leitfahigkeit noch durch Photoleitfahigkeitsmessungen konnte nachgewiesen werden, das Einzelleerstellen, Doppelleerstellen, oder Leerstellen-Sauerstoffpaare durch Abschrecken erhalten werden. Ungefahr 50% der durch Abschrecken erzeugten Defekte heilten bei 300°K mit einer Wanderungsenergie von (0,81 ± 0,04) eV aus. Ein 0,4 eV oberhalb des Valenzbandes gelegenes Energieniveau wird mit diesen Defekten in Verbindung gebracht.
44 citations
TL;DR: In this paper, changes in the vertical distribution of acid-soluble ferrous and total iron in filtered lake water were measured weekly for 12 months using the organic reagent bathophenanthroline.
Abstract: Changes in the vertical distribution of acid-soluble ferrous and total iron in filtered lake water were measured weekly for 12 months using the organic reagent bathophenanthroline. Acid-soluble ferrous iron was present throughout all strata, the concentration fluctuating in a definite annual pattern. Values of Fe*+ changed hourly and followed a diurnal pattern, It is suggested that the concentration of Fe’+ in lake water is controlled by photochemical reactions and, perhaps, also by metabolic activity of microorganisms.
41 citations
TL;DR: In this article, the scattering of high-energy neutrons from liquid is discussed in terms of the Gram-Charlier series expansion of the incoherent scattering function, and it is shown that the series falls naturally into two parts.
Abstract: The scattering of high-energy neutrons from liquid ${\mathrm{He}}^{4}$ is discussed in terms of the Gram-Charlier series expansion of the incoherent scattering function. It is shown that the series falls naturally into two parts. The first part, which corresponds to keeping only the leading term in each coefficient in the limit of large momentum transfer $\ensuremath{\kappa}$ can be summed exactly and gives the impulse approximation (IA). The second part, which vanishes in the limit $\ensuremath{\kappa}\ensuremath{\rightarrow}\ensuremath{\infty}$, describes the effect of final-state interactions which are neglected in the IA. The first two coefficients in the latter series are evaluated and indicate that final-state interactions are not negligible in the recent experiments of Cowley and Woods, a fact which probably explains why these authors failed to see a sharp peak, due to the condensate, which had been predicted by Hohenberg and Platzman on the basis of the IA. It is also shown that final-state interactions produce a shift in the position of the maximum of the energy distribution of scattered neutrons, and the calculated value is in rough agreement with the value observed by Cowley and Woods.
40 citations
TL;DR: In this article, a study of the potentials developed across growing oxide films on zirconium alloys, and the currentvoltage characteristics of these oxide films has shown that a simple treatment of the oxidation potential to give transport numbers for ions and electrons is not possible for these alloys.
40 citations
TL;DR: The diffusion coefficient of 60Co in the b.c. β phase of 99.99% pure polycrystalline zirconium has been measured over the temperature range of 920 to 1700°c as discussed by the authors.
Abstract: The diffusion coefficient of 60Co in the b.c.c. β phase of 99.99% pure polycrystalline zirconium has been measured over the temperature range of 920 to 1700°c. The Arrhenius plot of log D versus 1/T shows some evidence of positive curvature above 1600°c but below that it is strictly linear and can be represented by: Anomalies in the concentration profiles were noted in experiments at temperatures below 1200°c. An account of their origin is suggested.
36 citations
TL;DR: In this paper, X-ray diffraction analysis has been used to examine the phase change introduced in U3Si thermally, by irradiation at 60°C and by plastic deformation.
35 citations
TL;DR: In this paper, the authors used replica electron microscopy of fracture surfaces to examine the stability towards irradiation of fission-gas bubbles and sintering pores in UO2.
33 citations
TL;DR: In this paper, the linear polarization sensitivity of a single rectangular Ge(Li) detector, 4 × 2.5 × 0.35 cm3, has been measured and used to study the polarization of the prominent γ-rays emitted in the 100Mo(α, 2n)102Ru reaction.
32 citations
TL;DR: The diffusion coefficient of 60Co in the bcc β phase of 9999% pure polycrystalline zirconium has been measured over the temperature range of 920 to 1700°c.
Abstract: The diffusion coefficient of 60Co in the bcc β phase of 9999% pure polycrystalline zirconium has been measured over the temperature range of 920 to 1700°c The Arrhenius plot of log D versus 1/T shows some evidence of positive curvature above 1600°c but below that it is strictly linear and can be represented by: Anomalies in the concentration profiles were noted in experiments at temperatures below 1200°c An account of their origin is suggested
TL;DR: The phase equilibria in the system ZrCr2 have been studied by metallography, X-ray and electron diffraction, electron-probe microanalysis, hardness and thermal analysis in the composition ranges 0-2.25 Wt.% chromium and 0-2400 p.m. oxygen.
Abstract: Phase equilibria in the system ZrCrO have been studied by metallography, X-ray and electron diffraction, electron-probe microanalysis, hardness and thermal analysis in the composition ranges 0–2.25 Wt.% chromium and 0–2400 p.p.m. oxygen. A binary (α-zirconium + ZrCr2) eutectoid forms over a temperature range that expands with oxygen concentration up to about 135 °C for a 2400-p.p.m.-oxygen alloy. Oxygen also increases the chromium concentration of the eutectoid from between 0.7 and 0.95 wt.% for a o-p.p.m.-oxygen alloy and 1.25 wt.% for a 2400-p.p.m.-oxygen alloy. The oxygen concentration of the α solid solution has a derived maximum of about 9000 p.p.m. at approximately 900 °C. The crystal structure determined for ZrCr2 (MgCu2 type, a = 7.21 A ) confirms earlier work. The impurity iron dissolves completely in ZrCr2 but, up to 3 wt.% iron, has no observable effect on the lattice parameter. Outstanding microstructural features are the formation of a twinned martensitic product in quenched 0.2 to 1.5 wt.% chromium alloys, the existence of a hexagonal omega phase ( a = 5.02 A , c = 3.12 A , c a = 0.622 ) in a quenched 2.25-wt.%-chromium alloy and the appearance, at certain cooling rates, from the β and α + β regions of a grain-boundary “alpha-like” phase.
TL;DR: In this article, the Coulomb excitation of 28Si with 60 MeV 32S ions was studied and a mean life τm = 0.73 ± 0.05 ps and static quadropole moment Q =0.22 − 0.09 b were measured.
TL;DR: The pairing model of nuclear physics for a single j shell is shown to define a para-Fermi statistics of order j + 1 2 ; the parafermion is a pair with total spin zero and is usually represented by the quasi-spin raising operator of Kerman as mentioned in this paper.
TL;DR: In this paper, an acid-free solvent extraction technique, using bathophenanthroline, was proposed for measuring dissolved ferrous iron in filtered lake water, where the absence of HCl from the reagents eliminates the influence of acid and light on ferrous IR determinations.
TL;DR: In this paper, the properties of three Si(Li) detectors have been studied over the temperature range 8.5 to 200°K, and the best performance was achieved in the range 50 to 80°K.
TL;DR: In this paper, the L-subshell conversion line intensity ratios of five pure M1 transitions have been measured with the Chalk River iron-free, π√2 β-spectrometer at momentum resolutions ranging from ≈ 0.04% to 0.19%.
TL;DR: In this paper, the transverse position coordinates of a charged particle moving through an end zone of a quadrupole lens are derived by iterating integral equations obtained from the first-order differential equations.
TL;DR: In this paper, the energy dependence of lattice disorder has been studied by implanting bismuth ions of energy 20 to 225 keV into silicon crystals at room temperature, and the observed disorder increases linearly with implantation energy over the whole range studied.
Abstract: The energy dependence of lattice disorder has been studied by implanting bismuth ions of energy 20 to 225 keV into silicon crystals at room temperature. Implant doses have been kept below 6 × 1013 ions cm−2 to avoid approaching “saturation” disorder. Lattice disorder has been measured by means of the orientation dependence of the backscattered yield of a 1.0 MeV helium ion beam (i.e. by the “channeling” technique). Within the experimental precision, the observed disorder increases linearly with implantation energy over the whole range studied. This linear dependence is consistent with the Kinchin-Pease equation, but its slope is at least a factor of two greater than the predicted value. Possible explanations for this discrepancy are discussed. The most reasonable one is that the disorder measured by the channeling technique includes not only the atoms that have been ejected into interstitial positions by the implantation, but also some of the lattice distortion resulting from this primary damage.
[Russian text Ignored].
TL;DR: In this article, pure water, acidified water, and aqueous nitrous oxide solutions have been irradiated with ≈ 100 ns pulses of electrons giving doses between 1019 and 1021 eV gminus;1.
TL;DR: In this article, experiments were made with Zircaloy-2 tubes containing axial slits and they showed that failure stress at 20 and 300 °C is increased by neutron irradiation.
TL;DR: A device for slicing cylindrical polyacrylamide gels with the following advantages: handling of the gel is simple and it need not be frozen, fractionation is rapid and could probably be fully automated if desired.
TL;DR: The thermal conductivities of sintered pellets of ThO2-1.3 wt% U02 were measured at 60°C before and after irradiation.
Abstract: The thermal conductivities of sintered pellets of ThO2-1.3 wt% U02 were measured at 60°C before and after irradiation. The irradiation temperature was below 156°C, and the exposures varied from 3.1 × 1014 to 4.7 × loL7 fissions/cm3. Each fission fragment damaged a region of 2.2 × 10-16 cm3 with the reduction in conductivity saturating by about 1017 fissions/cm3. Samples having exposures from 1015 to 1016 fissions/cm3 were annealed isothermally at 651 °C or isochronally from 300° to 1200° C to study the annealing of damage. Most of the annealing occurred between 500° and 900°C. The width of this interval plus the slow isothermal annealing suggest that the damage is annealed by a number of single order processes with a spectrum of activation energies from 1.8 to 3.9 eV or, less probably, by a high order process with an activation energy of 3.55 ± 0.4 eV.
Patent•
18 Nov 1969TL;DR: In this paper, a light source consisting of a gasfilled pressure vessel to which light from a laser is admitted and focused to a point is revealed, and light emitted by the gas at the focal point is directed by a mirror system to an output pupil to provide a highly collimated light beam.
Abstract: This application discloses a light source consisting of a gasfilled pressure vessel to which light from a laser is admitted and focused to a point. Light emitted by the gas at the focal point is directed by a mirror system to an output pupil to provide a highly collimated light beam.
TL;DR: In this article, the resonant perturbation of spin waves caused by zinc impurities in MnF2 has been observed by means of neutron inelastic scattering, and a Green-function calculation of the impurity-induced changes in the spinwave frequencies and the widths of the neutron groups gives reasonable agreement with experiment.
TL;DR: In this article, the experimental observation of the inelastic scattering of slow neutrons by two-magnon processes and theoretical calculations which account for the shape and wave-vector dependence of the spectrum were presented.
Abstract: We report the experimental observation of the inelastic scattering of slow neutrons by two-magnon processes and present theoretical calculations which account for the shape and wave-vector dependence of the spectrum.
TL;DR: In this article, the authors present a discussion on several studies, such as sending-end filtering, stability, load flow, and dc filter requirements, and a concept for determination of mid-span ground clearance is presented.
Abstract: A dc transmission system proved to be the most economic mode for moving power from the Nelson River to southern Manitoba. This paper presents discussion on several studies, such as sending-end filtering, stability, load flow, and dc filter requirements. The electrical design of the lines is discussed, and a concept for determination of mid-span ground clearance is presented.
TL;DR: In this paper, it was suggested that the cone-to-spiral magnetic transition in holmium metal near 20mm diameter is caused by a soft spin-wave mode of nonzero wave vector.
Abstract: It is suggested that the cone-to-spiral magnetic transition in holmium metal near 20\ifmmode^\circ\else\textdegree\fi{}K is caused by a soft spin-wave mode of nonzero wave vector. Neutron inelastic scattering measurements are presented which support this proposal.
TL;DR: In this article, the effective neutron capture cross section of 35Cl for (n, γ) and p reactions has been measured by the activation method by irradiating samples in a reactor with and without a cadmium cover and by assuming a 1/v dependence in the sub-cadmium region, the 2200 m/sec cross sections and the resonance integrals for both reactions have been calculated using the Westcott convention