[en] The screen allows X-ray and γ ray conversion into luminous photons. It includes a thick layer of a material deposited on a support and made of Gd₂O₂S doped with a rare earth type, an organic polymer allowing the doped material to be thickened and having a good resistance to radiations together with a good transparency to the emission light of the doped material

[en] High-spin states in ¹⁶⁶Yb have been studied via the ¹⁵⁴Sm (¹⁶O,4n)¹⁶⁶Yb reaction with 80 Mev ¹⁶O ions from the NBI tandem accelerator. γ-γ coincidence data were accumulated with an array of four Ge(Li) and four NaI(Tl) detectors to favour high multiplicity events. Totally about 3 x 10⁸ events were accumulated in the coincidence experiment. Measurements of the angular distribution of the γ-radiation and the conversion coefficients were furthermore performed. Four weakly populated side bands are observed besides the yrast cascade which is followed up to its 24⁺ member. The ground state band has thus been identified to its 18⁺ state, while the crossing Stockholm band becomes the yrast band from its 16⁺ member. The S-band is established from its 12⁺ state. The observed level energies and transition rates are well reproduced in calculations within the particle rotor model. (author)

[en] The study of constrained dynamical systems is a subject of interest because all the theories exhibiting gauge invariance are constrained. In a previous work the theory of canonical transformations for these systems was developed. This theory introduces the concept of an equivalence class of canonical transformations for these systems was developed. This theory introduces the concept of an equivalence class of canonical transformations and suggests studying the actions of Lie groups on these systems in this framework. Here the actions of groups for singular systems are studied in the framework of the theory of canonical transformations for presymplectic systems. Symplectic realizations as well as nonsymplectic ones arise in a natural way. As a typical example the author constructs the Poincare realizations for the relativistic free massive particle

[en] Ion processing can induce contamination on the bombarded surface. However, this process is essential for the microelectronics device fabrication. Auger electron spectroscopy has been used to study the simultaneous deposition of carbon impurity during ion bombardment of magnetron rf-sputtering deposited aluminum oxide film. Ion bombardment on aluminum oxide results in a preferential removal of surface oxygen and a formation of a metastable state of aluminum suboxide. Cosputtered implanted carbon contaminant appears to have formed a new state of stoichiometry on the surface of the ion bombarded aluminum oxide and existed as an aluminum carbide. This phase has formed due to the interaction of the implanted carbon and the aluminum suboxide. The Ar⁺ ion sputter etching rate is reduced for the carbon contaminated oxide. The electrical resistance of the aluminum oxide between two gold strips has been measured. It is found that the electrical resistance is also reduced due to the formation of the new stoichiometry on the surface

[en] The development of large and complex nuclear and process plants requires high-performance control systems, designed with rigorous multivariable techniques. This work is part of an analytical study demonstrating the real potential of multivariable methods. It covers every step in the design of a multi-variable controller for a Gentilly-2 type CANDU 600 MWe nuclear power plant using the Inverse Nyquist Array (INA) method. First the linear design model and its preliminary modifications are described. The design tools are reviewed and the operations required to achieve open-loop diagonal dominance are thoroughly described. Analysis of the closed-loop system is then performed and a feedback matrix is selected to meet the design specifications. The performance of the controller on the linear model is verified by simulation. Finally, the controller is implemented on the reference non-linear model to assess its overall performance. The results show that the INA method can be used successfully to design controllers for large and complex systems

[en] The investigation of the occurrence of nonlinear electrostatic waves (viz., solitary waves and double layers) in degenerate plasmas was the main concern of the article presented by Roy et al.[Phys. Plasmas 19, 033705 (2012)]. The equations of state used in the article were the limits explained by Chandrasekhar [Mon. Not. R. Astron. Soc. 170, 405 (1935)]. It was designated as “misleading” by some authors, which is opposed in this reply with explanation.

[en] The crystallization kinetics of strontium tungstate from unstirred saturated solutions in sodium tungstate melts was studied by continuous cooling from initial crystallisation temperatures T₀ = 1000⁰ to 800 ⁰C to room temperature at cooling rates Rsub(T) = 0.67⁰ to 3.3 ⁰C min^-1. The main crystal growth was diffusion rate-controlled; the final crystal growth was rate-controlled by the development rate of excess solute concentration. The estimated diffusion rate constant (ksub(D)) values increased with cooling rates and initial crystallisation temperatures. They are higher than the rate constants for diffusion-controlled growth of calcium tungstate from sodium tungstate melts, but very much smaller than those for strontium tungstate from lithium chloride melts. (author)

[en] Investigations following the rupture of Pickering Unit 1 pressure tube G16 in 1983, led to the shutdown of Units 1 and 2 for pressure tube replacement and numerous other upgrades. They were recommissioned in 1987 and 1988 respectively. This paper surveys the procedures used during the reactor physics recommissioning of these two reactors and presents the results of these measurements. Special note is made of the differences between this recommissioning work, and the initial commissioning of new CANDU reactors. From a physics point of view, the restarted units differed substantially from the original design. The main difference in the core configuration involved the conversion of 10 of the original adjuster rods into shutoff rods. The reactivities of the remaining adjusters were increased. These substantial changes to the core, together with the full core of fresh fuel, necessitated a complete set of reactor physics recommissioning experiments. Some of our procedures differed from those used to commission a new reactor. This was due mainly to the high levels of tritium in the moderator D₂O and to radiological hazards on the reactivity deck. Also, the high residual activities in the rebuilt cores lead to increased difficulties in neutron monitoring and higher subcritical neutron count rates (hence a higher than usual reactor power at first criticality). In general the results of our recommissioning measurements closely matched the results of presimulations using the OHRFSP and SMOKIN computer codes. Results for Unit 2 were generally better than those for Unit 1. This was due to improved procedures which resulted from our experiences with Unit 1. (author). 4 tabs., 9 figs

[en] A generalised method for the straightforward evaluation of Coulomb-Born cross sections for 1s → ns excitation of any hydrogen-like ion by electron impact is formulated. This new method does not involve partial-wave analysis and is very simple and economical for the computation of electron-ion scattering cross sections at any energy and for any value of n. The results cover energies up to six times the excitation threshold and for n and Z both varying from two to infinity. The dependence of the scattering cross section on n and z is discussed. (author)

[en] Rotational bands in the neutron-deficient Pb nuclei ^{192,194,196-201}Pb have been reported recently. Band members are connected by L = 1 transitions, with crossover L = 2 transitions observed at the higher γ-ray energies. Regular and irregular patterns of γ-ray energies are observed. Conversion coefficients determined from intensity balance suggest the L = 1 transitions are M1. The bands have generally been interpreted as collective oblate, involving deformation aligned high-j proton configurations such as π(s_1/2^-2h_9/2i_13/2), and rotation aligned i_13/2^-n neutrons. Evidence for a similar band in ¹⁹³Hg has been obtained. ¹⁹³Hg was populated in the reaction ¹⁷⁶Yb(²²Ne,5n) at E_i(²²Ne) = 110 MeV. Reaction γ rays were detected with the Ge detector array HERA. A new 'collective' structure was observed with E_x>5.7 MeV. States of the structure extend from I≥47/2 to I +10, and they decay with competing dipole and quadrupole transitions. The ratio B(M1)/B(E2), ∼ 2μ²/(e b)², is approximately 10x lower in ¹⁹³Hg than in the Pb bands. The lowest member is produced with ∼20% of the ¹⁹³Hg cross section. Evidence for a similar band in ¹⁹⁶Hg will be presented at this meeting