[en] A bromine doped self-quenching Geiger-Mueller tube having an operational life expectancy in excess of 1,200 hours at a temperature of 315⁰C is described. The tube comprises a passivated metal coated cathode which is conditioned or aged for operation at room temperature, thus obviating the necessity of thermally cycling the tube at progressively elevated temperatures. Useful metal coatings for the cathode include chromium, platinum, and nickel-copper alloys deposited in a layer less than about 1 mil thick. A method for passivating the metal coated cathode and subsequently conditioning the tube and its contents is disclosed. (auth)

[en] A highly sensitive Geiger-Mueller radiation detector with improved temperature stability and working life uses a cylindrical cathode made from a nickel copper alloy preferably containing predominantly nickel. This alloy is resistant to attack by halogen quench gases used in the tube and provides an excellent surface for the electrodeposition of platinum to provide a low porosity surface

[en] We have experimentally studied the local ionization state of the plasma in a low-voltage highly ionized arc. We investigate a low-voltage cesium arc at vapor pressures of papprox.1 torr, and currents up to 50 A. The density of cesium atoms is measured by resonance holographic interferometry, with interferograms recorded on double exposures. We present a schematic optical system whose basic elements are a dye laser with an optical pump, and a double-beam Mach-Zehnder interferometer. The electron temperature and charged-particle density are measured spectroscopically, using the intensity and spectral distribution of the 6P recombination continuum of cesium. We compare our atomic density data with the equilibrium values computed from the experimental T_e and n using the Saha formula. In this way we determine the degree of ionization in the plasma, and we establish that local ionization equilibrium exists throughout the plasma volume. We illustrate this by means of an example in two regimes

[en] The phonon dispersion curves as well as high energy magnetic excitations in La₂CuO₄ were investigated by inelastic neutron scattering on a large single crystal (V ∼ 0.8 cm³). A few low energy phonon branches were determined at the Kurchatox Institute in Moscow, whereas the main part of the experiments was carried out at Saclay. The magnetic excitations were studied up to E + 76.5 meV at 18 K and 295 K. They were found to exhibit a linear dispersion of 0.89 eV · Angstrom. Nearly all phonon branches were determined in the main symmetry directions (100), (110) and (001) (in tetragonal notation). Most measurements were done at room temperature but additional measurements were performed above the structural phase transition (495 K) to explore the influence of the tilting of the octahedra on the lattice dynamics

[en] Single hadron azimuthal asymmetries of positive and negative hadrons produced in muon semi-inclusive deep inelastic scattering off longitudinally polarised deuterons are determined using the 2006 COMPASS data and also combined all deuteron COMPASS data. For each hadron charge, the dependence of the azimuthal asymmetry on the hadron azimuthal angle φ is obtained by means of a five-parameter fitting function that besides a φ-independent term includes four modulations predicted by theory: sin φ, sin 2φ, sin 3φ and cos φ. The amplitudes of the five terms have been extracted, first, for the hadrons in the whole available kinematic region. In further fits, performed for hadrons from a restricted kinematic region, the φ-dependence is determined as a function of one of three variables (Bjorken-x, fractional energy of virtual photon taken by the outgoing hadron and hadron transverse momentum), while disregarding the others. Except the φ-independent term, all the modulation amplitudes are very small, and no clear kinematic dependence could be observed within experimental uncertainties. (orig.)