Dispersion and radiating ability of relativistic electronic gas

In the paper the dispersion and conditions of formation of nonequilibrium radiation in the relativistic electronic gas are considered. For a case of a high-density electron bunch in the cw-approach and a wave-zone unharmonic oscillator the general kind of transfer plane-parallel front of nonequilibrium radiation equation is obtained.Розглянуті дисперсія й умови формування нерівновагого випромінювання в релятивістському електронному газі. Для випадку великої густини електронного згустку в квазістаціонарному наближенні в хвильовій зоні ангармонічного осцилятора отримано загальний вид рівняння переносу плоскопараллельного фронту нерівновагого випромінювання.Рассмотрены дисперсия и условия формирования неравновесного излучения в релятивистском электронном газе. Для случая большой плотности электронного сгустка в квазистационарном приближении в волновой зоне ангармонического осциллятора получен общий вид уравнения переноса плоскопараллельного фронта неравновесного излучения

Some aspects of the nonlinear interaction between global teleconnection patterns

The chaotic behavior in the global climate system of the Earth and the nonlinear interaction between some teleconnection patterns during different epochs of the twenty century are studied. To study the influence of low frequency variations, the wavelet decomposition is applied. We use the cross-redundancy and Granger causality for detailed componentsof the wavelet decomposition.Анализируется хаотическое поведение в глобальной климатической системе Земли и нелинейное взаимодействие между телеконнекционными паттернами на протяжении разних эпох 20-го столетия. Для определения влияния низкочастотных вариаций применен метод вейвлет-разложений. Использована взаимная информация и причинность Грангера для анализа детализованных компонент вейвлет-разложений.Аналізується хаотична поведінка у глобальній кліматичній системі Землі й нелінійна взаємодія між телеконекційними паттернами протягом різних епох 20-го сторіччя. Для визначення впливу низькочастотних варіацій застосовано метод вейвлет-розкладань. Використано взаємну інформацію та причинність Грангера для деталізованих компонентів вейвлет-розкладань

Compact electron linac LU-7-2 for radiography of large-scale objects

At RFNC-VNIIEF there was started up a compact LU-7-2 linear electron accelerator designed for industrial application in the field of radiography of objects with a large mass thickness as well as for development of radiation technologies. For accelerator microwave power supply there was used a magnetron operating on a wavelength of 10.7 cm with a pulse power of 2.5 MW. Accelerating structure was created on the basis of a circular disc-loaded waveguide with varying geometry of accelerating cells, operating on a traveling wave of 2π/3 mode. Electrons are injected by a diode type 50 kV electron gun. The achieved parameters allow to use the accelerator for radiography of objects with a large mass thickness

Galactic cosmic rays-clouds effect and bifurcation model of Earth global climate

The possible physical linkage between the cosmic rays cloud and indirect aerosol effects is discussed using the analysis of the first indirect aerosol effect (Twomey effect) and its experimental representation as the dependence of mean cloud droplet effective radius versus aerosol index defining the column aerosol number. It is shown that the main kinetic equation of Earth climate energy-balance model is described by the bifurcation equation (relative to the surface temperature of the Earth) in the form of fold catastrophe with two controlling parameters defining the variations of insolation and Earth magnetic field (or cosmic rays intensity in the atmosphere) respectively. The results of comparative analysis on the time-dependent solution of Earth climate energy-balance model taking into account nontrivial role of galactic cosmic rays and the known experimental data on the paleotemperature from the Vostoc ice core are presented. In the framework of the bifurcation model (i) the possibility of abrupt glacial climate changes analogous to the Dansgaard-Oeschger events due to stochastic resonance is theoretically argued, (ii) the concept of the climatic sensitivity of water (vapour and liquid) in the atmosphere is introduced. This concept reveals the property of temperature instability in the form of so-called hysteresis loop. On the basis of this concept it is shown that the simulated time series of global ice volume over the past 730 kyr are in good agreement with time series of seawater δ¹⁸O (ice volume proxy). (iii) Also, the so-called "doubling CO₂" problem is discussed

Production of radiation destructant from spent butyl rubbers on the linac LU-10-20

Radiation methods of materials modification applied in technological chains can have significant economical and ecological advantages as compared to the established chemical, thermal and mechanical methods. Each year the problems of nature resources economy through the use of production and consumption wastes acquire a more significant value, as it allows to solve also ecological issues along with economical ones. This is mostly acute in relation to polymeric systems based on saturated rubbers, for example butyl rubber (BR) used in tyres industry, as due to their high resistance to the action of oxygen, ozone, solar radiation and bacteria they contaminate the environment for rather a long period. At VNIIEF and KSPU there were carried out experiments on application of electron beams with energy from 6 to 10 MeV for radiation destruction of spent rubber based on butyl rubber. Reclaim is tested in the formulation of initial diaphragm mixture, rubber mixture for producing rubberized fabric, roofing

Gluon polarization in the nucleon from quasi-real photoproduction of high-pT hadron pairs

We present a determination of the gluon polarization Delta G/G in the nucleon, based on the helicity asymmetry of quasi-real photoproduction events, Q^2<1(GeV/c)^2, with a pair of large transverse-momentum hadrons in the final state. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarized muon beam scattered on a polarized 6-LiD target. The helicity asymmetry for the selected events is = 0.002 +- 0.019(stat.) +- 0.003(syst.). From this value, we obtain in a leading-order QCD analysis Delta G/G=0.024 +- 0.089(stat.) +- 0.057(syst.) at x_g = 0.095 and mu^2 =~ 3 (GeV}/c)^2.Comment: 10 pages, 3 figure

Experimental study of negative photoconductivity in n-PbTe(Ga) epitaxial films

We report on low-temperature photoconductivity (PC) in n-PbTe(Ga) epitaxial films prepared by the hot-wall technique on -BaF_2 substrates. Variation of the substrate temperature allowed us to change the resistivity of the films from 10^8 down to 10_{-2} Ohm x cm at 4.2 K. The resistivity reduction is associated with a slight excess of Ga concentration, disturbing the Fermi level pinning within the energy gap of n-PbTe(Ga). PC has been measured under continuous and pulse illumination in the temperature range 4.2-300 K. For films of low resistivity, the photoresponse is composed of negative and positive parts. Recombination processes for both effects are characterized by nonexponential kinetics depending on the illumination pulse duration and intensity. Analysis of the PC transient proves that the negative photoconductivity cannot be explained in terms of nonequilibrium charge carriers spatial separation of due to band modulation. Experimental results are interpreted assuming the mixed valence of Ga in lead telluride and the formation of centers with a negative correlation energy. Specifics of the PC process is determined by the energy levels attributed to donor Ga III, acceptor Ga I, and neutral Ga II states with respect to the crystal surrounding. The energy level corresponding to the metastable state Ga II is supposed to occur above the conduction band bottom, providing fast recombination rates for the negative PC. The superposition of negative and positive PC is considered to be dependent on the ratio of the densities of states corresponding to the donor and acceptor impurity centers.Comment: 7 pages, 4 figure

Measurement of the Spin Structure of the Deuteron in the DIS Region

We present a new measurement of the longitudinal spin asymmetry A_1^d and the spin-dependent structure function g_1^d of the deuteron in the range 1 GeV^2 < Q^2 < 100 GeV^2 and 0.004< x <0.7. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarised muon beam and a large polarised 6-LiD target. The results are in agreement with those from previous experiments and improve considerably the statistical accuracy in the region 0.004 < x < 0.03.Comment: 10 pages, 6 figures, subm. to PLB, revised: author list, Fig. 4, details adde