Generation of multiply charged refractory metals in an electron-cyclotron resonant discharge in a direct magnetic trap

The possibility of additional ionization of refractory metal ions in the vacuum arc plasma injected to a magnetic trap due to additional heating of electrons by microwave radiation under the conditions of electron-cyclotron resonance is demonstrated. High-power short-wave radiation of gyrotrons used in experiment makes it possible to work with a higher (on the order of 10¹³ cm⁻³) density of the plasma and to ensure the confinement parameter at a level of 3 × 10⁸ cm⁻³ s at an electron temperature sufficient for multiple ionization.     

Effect of the pulse repetition rate on the composition and ioncharge-state distribution of pulsed vacuum arcs

The plasma composition and ion charge-state distributions of pulsed vacuum arcs have been investigated for carbon, aluminum, silver, platinum, and tantalum cathodes using a time-of-flight (TOF) charge-to-mass spectrometer. With the exception of carbon, it was found that all results depend on the arc pulse repetition rate, a fact which, up to now, has not been reported in the literature. It is shown that adsorption of gas on the cathode between are pulses leads to contamination of the metal plasma and to a reduction of metal ion charge states. These usually undesired effects can be avoided by operating at high arc pulse repetition rates of order 10 Hz or more. The results can be interpreted in terms of cathode spot type 1 (on contaminated cathode surfaces) and type 2 (on clean surfaces) which are well known from their different brightness and erosion behaviour. The transition between these modes was found to be gradual     

Summation of signals during energy extraction from 3-cm range oversized cavities

Data on the summation of signals from two synchronously operating resonant microwave (3-cm) compressors with oversized cavities are described. The energy was extracted with interference switches. The summation was performed in a waveguide tee and a 3-dB three-slot bridge. For a signal duration of ∼30 ns at a level of 0.5, a peak power of ∼1 MW, and an efficiency of ∼30%, a gain was found to approach ∼11 dB.     

Acousto-optic processing of images in visible and ultraviolet light

The paper concerns processing of optical images by means of tunable acousto-optic filters. Experimental and theoretical research showed that longitudinal chromatic aberrations cause a suffcient decay of the spatial resolution in the devices. It is shown that a proper choice of an optical cheme of an imager reduces the longitudinal aberrations all over the tuning range of the filters.     

Extreme-ultraviolet source based on the electron-cyclotron-resonance discharge

An extreme-ultraviolet (EUV) source based on a low-pressure discharge sustained in a magnetic trap by the high-power millimeter-wave radiation under electron-cyclotron-resonance (ECR) conditions is discussed. Multiply charged ions are efficiently generated and excited in such a discharge (tin ions injected into the trap from a vacuum-arc discharge were used) and emit line radiation in the desired wavelength range. A radiation power of 50 W in a wavelength range of 13.5 nm ± 1% and an efficiency of about 1% for the conversion of the micro-wave radiation absorbed in the plasma to the extreme ultraviolet radiation were achieved in the preliminary experiments.     

Suppression of Small-Scale Magnetic Field Generation by Transformation of the Kinetic Energy Spectrum

Journal of Experimental and Theoretical Physics - The stabilization of a small-scale dynamo caused by a change in the energy spectrum of a conducting plasma flow is investigated. Such a change in...     

Effect of magnetic field on tempering processes in silicon iron

The effect of magnetic fied on the annealing of silicon iron (3% Si) was studied in the temperature range 480–680°C. The imposition of a magnetic field at 480°C leads to more complete tempering by comparison with similar annealing without field. The effect of the magnetic field on the primary recrystallization texture of the silicon iron is shown: this is expressed in the enhanced scattering of deformation type orientations in the annealing texture.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 82–87, January, 1973.     

Study of the blow-up of solutions of systems of equations of hydrodynamic type

Mathematical Notes - We study the initial boundary-value problem for three-dimensional systems of equations of pseudoparabolic type. The system is similar to the Oskolkov system, but differs from...     

Observation of the decay B- → D(s)((*)+) K- ℓ- ν(ℓ)

We report the observation of the decay B- → D(s)((*)+) K- ?- ν(?) based on 342 fb(-1) of data collected at the Υ(4S) resonance with the BABAR detector at the PEP-II e+ e- storage rings at SLAC. A simultaneous fit to three D(s)(+) decay chains is performed to extract the signal yield from measurements of the squared missing mass in the B meson decay. We observe the decay B- → D(s)((*)+) K- ?- ν(?) with a significance greater than 5 standard deviations (including systematic uncertainties) and measure its branching fraction to be B(B- → D(s)((*)+) K- ?- ν(?)) = [6.13(-1.03)(+1.04)(stat)±0.43(syst)±0.51(B(D(s)))]×10(-4), where the last error reflects the limited knowledge of the D(s) branching fractions.     

Roll waves in an annular channel

The goal of this study is to analytically construct periodic wind perturbations in an annular channel that are numerically produced by a regularized model. R. Dressler’s technique in the shallow water approximation is used to prove the nonexistence of smooth periodic solutions, and discontinuous solutions related to roll waves on inclined surfaces are constructed. The constraints on the accelerating and dissipating forces are obtained under which periodic solutions can exist. A numerical analysis of the problem is carried out, and a qualitative comparison of the numerical and theoretical results is presented.