Atomic Energy of Canada Limited

About: Atomic Energy of Canada Limited is a company organization based out in Ottawa, Ontario, Canada. It is known for research contribution in the topics: Neutron & Zirconium alloy. The organization has 4845 authors who have published 4826 publications receiving 102951 citations.

Nature of the 5f electrons in uranium nitride: A photoelectron spectroscopic study of UN, U, UO/sub 2/, ThN, and Th

Abstract: Ultraviolet and x-ray-photoelectron spectra of core and valence levels in U metal, UN, U${\mathrm{O}}_{2}$, Th, and ThN have been obtained. These spectra demonstrate the existence in uranium nitride of a sharp band of $f$ states (containing 2.2\ifmmode\pm\else\textpm\fi{}0.5 electrons) at the Fermi level. The anomalously broad $4f$ core levels in UN are discussed in terms of several possible energy-loss mechanisms, including configuration interaction and alternating valency. No change is seen in the density of $f$ states of UN on cooling through the antiferromagnetic transition.

Experimental Studies of Damping and Hydrodynamic Mass of a Cylinder in Confined Two-Phase Flow

Abstract: This paper presents the results of experiments done to determine the effects of cylinder mass and flow regime on the damping and hydrodynamic mass characteristics of a cylinder vibrating in simulated two-phase air-water flows. It was found that two-phase damping varied in inverse proportion to the combined cylinder and two-phase hydrodynamic masses. This is in agreement with a postulated detuning process for damping in two-phase flow. As in earlier studies, the two-phase hydrodynamic mass was found to be less than that calculated from the mixture density, for all flow conditions. 4 refs.

Elastic Scattering of Identical Spin-Zero Nuclei

Abstract: Elastic scattering measurements have been carried out on the ${\mathrm{C}}^{12}$+${\mathrm{C}}^{12}$ and ${\mathrm{O}}^{16}$+${\mathrm{O}}^{16}$ systems in the energy range from 6 to 35 Mev using heavy-ion beams from the Chalk River tandem accelerator and Au-Si surface barrier detectors. At energies below the Coulomb barriers the Mott scattering predictions are in excellent accord with the measurements as functions of both angle and energy. At energies above the barrier the O+O excitation curve drops exponentially below the Mott predictions to a value of 10 mb/sr at ${E}_{\mathrm{c}.\mathrm{m}.}=16.5$ Mev and remains approximately constant thereafter at that value; in contrast, the C+C excitation curve shows marked resonant interference structure. The states involved have $\ensuremath{\tau}\ensuremath{\gtrsim}{10}^{\ensuremath{-}21}$ sec, large compound elastic branching ratios $\frac{{\ensuremath{\Gamma}}_{c}}{\ensuremath{\Gamma}}$, and appear to correspond to resonant absorption of high-order partial waves, hence have high angular momentum. It is suggested that these states reflect a quasi-molecular interaction mechanism which is involved in grazing collisions of these nuclei and which is critically dependent upon the structure of the nuclei involved.

Binding energies in cubic metal surfaces

Abstract: Surface binding energies are calculated using Morse potentials for the (100), (110) and (111) surfaces of seven f.c.c. and 9 b.c.c. metals. Estimates are made for a further seven metals. Surface relaxation effects are included and their effect discussed. The surface binding energies are found to be greater than the sublimation energy per atom of the solid. Qualitative arguments are proposed to explain the ordering of binding energies between crystal faces. Comparison with experimental data for the adsorption energies of tungsten atoms on tungsten crystal faces indicates the plausibility of the calculated valucs.