Papers by Keyword: Pulsed Electron Beam

Abstract: The paper presents measurements taken with a high-speed infrared pyrometer for the surface temperature of VT1-0 titanium alloy during pulsed electron beam irradiation at different pulse energy densities. Also presented are numerical simulation data on thermal fields for the same conditions, showing a good agreement with the measurements. The results demonstrate that the heating rate of the VT1-0 surface depends on the main beam parameters, and its solidification occurs at a temperature ≈ 280 °C lower than the melting point.

Abstract: Wheat grain has been irradiated by 200 keV and 305 keV of pulsed electron beams for changing of sowing parameters. Total microbial number, germination and germination energy were compared for both of electron kinetic energy settings for the same ranges of the energy input. The electron beam of 305 keV showed better disinfecting effect for energy input values of less than 4 J/g. That mode eliminates seed germination ability after irradiation of more than 2 J/g and can be used for grain storing. The mode of 200 keV beam keeps seed germination ability up to 5 J/g with the similar disinfecting effect after the irradiation energy input of more than 4 J/g. This mode can be used for pre-sowing seed treatment procedure.

Abstract: The theoretical model for investigation of the electron beam propagation in the gas medium is developed. The main feature of the model is the possible to analyze the time evolution of the differential current which allows obtaining the energy distribution function of electron. The equations for electromagnetic fields created by the electron beam are the time dependence function. The elastic collision and ionization are considered as a basic interaction processes between beam and gas medium.

Abstract: The paper presents the results of the experimental investigation of the pulsed electron beam propagation propagated in a drift tube filled with oxygen. The pressure was 50, 300, and 760 Torr in the drift tube. The experiments were carried out using a TEA-500 pulsed electron accelerator (450 kV accelerating voltage; 10 kA electron beam current; 80±1 ns pulse duration to the base; up to 200 J pulse energy; and 5 cm diameter beam). The electron beam was propagated in the drift tube (40 cm long), 14 cm in diameter composed of two sections equipped with two reverse current shunts. The experiments were carried out which fixed the absorbed dose registered on the walls of the drift chamber.

Abstract: Paper presents the results of experiments on multicapillary carbon-epoxy as a candidate material for a cathode of a pulsed electron accelerator. A high voltage pulse of 350 kV, 350 ns (FWHM) was applied to the cathode. The pulse repetition rate was 20 pps. The optical image of the cathode surface after 4×10⁴ shots of electron beam was changed as well as electrical characteristics of the electron diode.

Abstract: This paper presents results of study of dissipation processes of pulsed electron beam in the oxygen and hydrogen (300 Torr). These gases are chosen owing of their use as a operating environment at pulse plasmochemical synthesis of nanosized oxides of metals. Experimental studies are conducted on the laboratory TEU-500 electron accelerator (500 keV electron energy; 10 кА ejected electron current; 60 ns half-amplitude pulse duration; 5 pps pulse repetition rate; diameter of a bunch is 5 cm). The electron beam was removed in a drift pipe through the anode window which is the supporting lattice (with optical transparency of 95%) and through aluminum foil 140 microns thick. The pipe of drift is equipped with three shunts of the return current which are fixing a signal at the same time. The received results of researches allow to make a conclusion. It is necessary to increase length to 80 cm and diameter to 30 cm of a pipe of drift for optimum absorption of a pulse electron beam by operating gas, for obtaining high efficiency of electron accelerator of pulse plasmochemical synthesis of nanosized oxides of silicon and the titan.

Abstract: Influence of electron beam irradiation on the morphology and contact angle of polypropylene was investigated. Electron beam processing was carried out at 8 – 10 kV accelerating voltage and a pressure of 5 – 10 Pa. Beam current density was up to 4.5 A/cm², and the pulse duration - from 150 to 300 μs. The morphology of irradiated polymer material was studied by scanning-electron and atomic-force microscopy methods. It was established formation of extended equally oriented “hills” divided by “valleys”. The height of hills increases with the growth of energy flux density per pulse.

Abstract: For materials, science it is important to study the structure and behavior of matter at the deepest level. Currently, modern microscopes allow one to see the atomic structure of matter. Materials should be prepared in a special way, for research in the microscope, but thus the natural structure of the material may changed. Especially, the processes at the atomic level are difficult to explore. In a computer model of matter, one can account the properties of atoms and even its electron structure. In this paper, by molecular dynamics method the structure and evolution of the palladium and its compounds with hydrogen are investigated. In the work equilibrium structure of the crystal lattice of palladium was obtained and determined the equilibrium lattice parameter at different temperatures. The behavior of the hydrogen atom inside the crystal lattice of palladium was studied. The structural and diffusion properties system palladium-hydrogen were obtained

Abstract: The temperature fields arising in a Ti film – Al substrate system and bulk Ti specimen irradiated with a submillisecond intense electron beam are calculated in the one-dimension approximation. It is found that the temperature fields in the irradiated bulk Ti specimen and Ti film – Al substrate system differ greatly. Electron beam irradiation conditions which allow solid-phase and liquid-phase alloying of aluminum with titanium are defined

Abstract: The structure and properties of a Ti film – Al substrate system alloyed by an intense pulsed electron beam are studied. It is shown that electron beam melting of this system provides the formation of a multiphase submicrocrystalline structure with high strength and tribological properties in the surface layer. Irradiation modes, which allow an increase in the microhardness of the material and a decrease in its wear rate, are defined. Physical substantiation of this phenomenon is given.