1,237 research outputs found
Experimental test of the shadowing effect in Smith-Purcell radiation
The observation of a shadowing effect of a relativistic electron Coulomb field for the Smith-Purcell radiation generation is presented in this paper. For this purpose the surface current from the closest surface of grating element
to the electron beam was measured for a downstream one shadowed by upstream element. The experimental results showed that shadowing effect for Smith-Purcell radiation depends on grating geometry
Electromagnetic field features at interaction of relativistic electron with matter
The features of electromagnetic field of relativistic electrons passing through a hole in an absorbing screen as a function of the distance from the screen in the range of radiation formation length were investigated for the transversal and longitudinal field components. The analysis of the obtained results allows approving the existence of a semi-bare electron with a particularly deprived Coulomb field, which turns into the stable state of the usual electron at the distance of radiation formation length
Experimental Research of the Diffraction and Vavilov-Cherenkov Radiation Generation in a Teflon Target
Geometry of Vavilov-Cherekov (VChR) radiation when an electron moves close to
a dielectric target is in analogy to diffraction radiation (DR) geometry. In
this case we may expect DR generation from the upstream face of the target
besides that VChR. The joint observation of these booth types of radiation is
very interesting from the pseudo-photon viewpoint, which is applicable for
relativistic electrons. Unexpected results obtained in our experiment insist on
reflection about nature both DR and VChR. The experiment was performed on the
relativistic electron beam of the microtron of Tomsk Polytechnic University.Comment: This article will be published in Journal of Physic
The coherent Vavilov-Cherenkov radiation for a bunch length diagnostic
Coherent Vavilov-Cherenkov radiation generated by a 6.1MeV
bunched electron beam traveling in the vicinity of a solid dielectric target (PTFE and Paraffin) has been investigated experimentally. In addition, we have also demonstrated the simple scheme of the Cerenkov interferometer for non-invasive longitudinal electron bunch length diagnostics
Evolution of the Velocity Ellipsoids in the Thin Disk of the Galaxy and the Radial Migration of Stars
Data from the revised Geneva--Copenhagen catalog are used to study the
influence of radial migration of stars on the age dependences of parameters of
the velocity ellipsoids for nearby stars in the thin disk of the Galaxy,
assuming that the mean radii of the stellar orbits remain constant. It is
demonstrated that precisely the radial migration of stars, together with the
negative metallicity gradient in the thin disk,are responsible for the observed
negative correlation between the metallicities and angular momenta of nearby
stars, while the angular momenta of stars that were born at the same
Galactocentric distances do not depend on either age or metallicity. (abridged)Comment: Astronomy Reports, Vol. 86 No. 9, P.1117-1126 (2009
Radioluminescence properties of nanocomposite scintillators with BaF 2 fillers
In this paper, studies of the luminescence properties of nanocrystalline BaF 2 samples synthesized by laser ablation and pulse electron beam evaporation method are presented. The measurements of X-ray excited luminescence (XEL) showed the dependence between luminescence intensity and the shape of the spectrum on the morphology and particle size. Also, studies of X-ray excited luminescence, decay curves and optical transmittance for nanocomposite materials containing BaF 2 nanopowder are presented. Barium fluoride nanopowder, obtained by pulsed electron beam evaporation method is characterized by a lower intensity than the initial microcrystalline powder, but at the same time, XEL spectrum of the nanocomposite material with this nanocrystalline filler is more intense, then that for nanocomposite material with initial powder. © Published under licence by IOP Publishing Ltd
Noninvasive daily termokarting of the brain in ischemic stroke at of the craniocerebral hypothermia
THE CONTROL UNIT OF THE PULSE CATHODOLUMINESCENT ANALYZER
The control unit is designed for the pulse electron beam and luminescent analyzer (“KLAVI-R” equipment) in order to realize the strobe mode which should improve the capabilities of luminescent measurements.Работа выполнена при финансовой поддержке Минобрнауки РФ (стипендия Президента РФ - 2015) и УрФУ (грант молодым ученым - кандидатам наук)
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