Advanced Materials Research Vol. 1084

Abstract: The paper studies the processes occurring in low-temperature plasma in the magnetic field. It shows that the laser excitation of molecular oxygen can increase the fraction of singlet pairs formed as a result of collisions between oxygen and carbon molecules. This facilitates the separation of ¹²С and ¹³С isotopes.

Abstract: This work presents the experimental and theoretical research of low pressure discharge characteristics in a large sized hollow cathode using treated work pieces. The dependence of discharge voltage on gas pressure and system geometry has been obtained. It is demonstrated that the high plasma homogeneity with concentration up to 10¹² cm² and plasma temperature within the order of 1 eV is obtained. It is shown that the external discharge current enables the independent control of discharge current and its voltage.

Abstract: Necessary conditions of quasi-bound state formation of η-meson with isotopes ³He, ⁴He have been found within the framework of optical potential model. These conditions have been compared with the findings about helium nucleus densities and with the available information about ηN-scattering length. Thus, we have concluded that within the framework of discussed model η−³He quasi-bound state formation is not possible, but η−⁴He quasi-bound state formation is possible with great probability.

Abstract: The possibility of using radiation of relativistic electrons in optical fibers using the properties of dielectric materials for diagnosing beams was theoretically suggested by the authors X. Artru and C. Ray. (Nucl. Instrum. Meth. B vol. 309 (2013). The aforementioned work studies the properties of various types of radiation induced in fibers by the electromagnetic field of relativistic electrons. In this paper, we present the experimental research of the influence of surface waves on the radiation propagating along a fiber. The work also investigates the properties of various types of coherent millimeter wave radiation that was induced in dielectric fibers by the electromagnetic field of relativistic electrons. The results also include the experimental analysis of nature and properties of coherent radiation in fibers, the analysis being performed for different positions of fiber in relation to the electron beam.

Abstract: The article discusses the problem of radiation generated during the interaction between the field of relativistic charged particles and metamaterials based on a one-dimensional periodic wire structure. The work includes the experimental study of the reverse coherent transition radiation emitted by these structures in the millimeter wavelength range for two orthogonal directions of radiation polarization. Under the same experimental conditions, authors also compared the intensity of this radiation with the reverse transition radiation from solid conductive targets. The study elucidates the asymmetrical polarization of radiation emitted by a metamaterial wire structure.

Abstract: In an experiment conducted at the Tomsk synchrotron "Sirius", the photon yield of parametric X-ray radiation generated by 500 MeV electrons in a tungsten monocrystal in Bragg geometry has been studied. The (111) tungsten monocrystal, having a thickness of 1.7 mm and a surface mosaicity of not more than 80^², was oriented at the Bragg angle θ_B = 45^° to the direction of the electron beam. The photons were detected at the angle 2θ_B = 90° relative to the electron beam. A comparison of PXR angular distributions with calculations has been carried out with taking into account the actual conditions of the experiment.

Abstract: The review is devoted to the analysis of the present state-of-the-art and development trends of the new methods and equipment being developed in Tomsk Polytechnic University (TPU), for DC vacuum arc-based ion and plasma materials processing. The features and advantages are demonstrated for the method of high-concentration implantation with compensation of surface ion sputtering by metal plasma deposition, the method of metal plasma deposition under repetitively – pulsed ion mixing with ion beams and plasma flow formed in the «Raduga-5» source, and the method of coating deposition and ion implantation, including an application of the filtered DC metal plasma source and high-frequency short-pulsed negative bias voltage with a duty factor in the range 10–99 %.

Abstract: The system model «high power ion beam – metal» is suggested. Regularities of impulse formation of mechanical load in the volume of metal target subjected to the action of ion beams of different component composition in the range of power density 10⁷...10¹⁰ W/cm² have been considered. The influence of generation mechanisms on the profile and amplitude-to-time parameters of shock-wave excitation is studied.

Abstract: This paper considers the features of coherent synchrotron radiation generated when relativistic electron bunches pass the field of short magnets. A significant contribution to the spectral and angular characteristics of radiation can be made by a factor of the limited length of the magnetic field disposed along the trajectory of the electrons. Furthermore, a substantial contribution to these features can be made by a radiation coherence factor. This work comprises the theoretical analysis of these effects and the results of experimental studies in the millimeter wavelength range

Abstract: Ab initio calculations of electronic structures of Zr–H and Zr–He systems have been done. The influence of hydrogen or helium impurities on the electron density distribution of the host metal has been considered. Extremely inhomogeneous redistribution of the metal valence charge density within the first coordination sphere of the impurity was found. The character of the observed anisotropy depends on the impurity type.