The experimental study of the surface current excitation under the influence of a relativistic electron electromagnetic field

The problem of the surface current excitation in a conductive targets by a relativistic electron electric field as the origin of such radiation mechanisms as diffraction and transition radiation of relativistic electron was considered in frame of both surface current and pseudo-photon methods. The contradiction between these viewpoints in respect to the surface current on the target downstream surface necessitated the experimental test of this phenomenon. The test performed on electron beam of the 6 MeV microtron showed, that not any surface current is induced on the target downstream surface under the influence of a relativistic electron electromagnetic field in contrast to the upstream surface. This is important implication for the understanding of the forward transition and diffraction radiation nature.Comment: Was Presented at the symposium Channeling 2008 (Charged and Neutral Particles Channeling Phenomena), October 25 - November 1, 2008 Erice (Trapani - Sicily), Italy, and was accepted for publication in proceedings of symposiu

Shadowing of the electromagnetic field of a relativistic electron

In coherent radiation sources (diffraction radiation, Smith-Purcell effect, etc.) based on relativistic electrons passing by a material radiator, the electron self-field is partly shadowed after each part of the radiator over a distance of the order of the formation length g2l. This effect has been investigated on coherent diffraction radiation (DR) by electron bunches. An absorbing half-plane screen was placed at various distances L before a standard DR source (inclined half-plane mirror). The DR intensity was reduced when the screen was at small L and on the same side as the mirror. No reduction was observed when the screen was on the opposite side. The shadowing effect can significantly reduce the total energy radiated in a long radiator.Comment: Was Presented at the symposium Channeling 2008 (Charged and Neutral Particles Channeling Phenomena), October 25 - November 1, 2008 Erice (Trapani - Sicily), Italy, and was accepted for publication in proceedings of symposiu

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

“Shadowing” of the electromagnetic field of relativistic charged particles

VIII International Symposium Radiation from Relativistic Electrons in Periodic Structures (RREPS-09), Zvenigorod, Russia, Sept. 7-11, 2009International audienceIn radiation processes such as a transition radiation, diffraction radiation, etc. based on relativistic electrons passing through or near an opaque screen, the electron self-field is partly shadowed after the screen over a distance of the order of the formation length γ2λ. This effect has been investigated on coherent diffraction radiation (DR) by electron bunches. Absorbing and conductive half-plane screens were placed at various distances L before a standard DR source (inclined half-plane mirror). The radiation intensity was reduced when the screen was at small L and on the same side as the mirror. No reduction was observed when the screen was on the opposite side. It is worth noting that absorbing and conductive half-plane screens produce the same shadowing effect. The shadowing effect is responsible for a bound on the intensity of Smith-Purcell radiation

Endothelial Dysfunction as a Consequence of Endothelial Glycocalyx Damage: A Role in the Pathogenesis of Preeclampsia

The endothelial glycocalyx is an intravascular compartment which consists of carbohydrate part of membrane glycoconjugates, free proteoglycans and associated proteins. It is thought to play an important role in the vascular tone regulation, vascular permeability and thromboresistance. It was suggested that the leading cause of endothelial dysfunction in various cardiovascular, inflammatory, and kidney diseases is the damage of the endothelial glycocalyx. This review presents the changes in the composition and structure of the endothelial glycocalyx in the settings of damage and under systemic inflammatory response, and the impact of these changes on the functions of endothelial cells and intercellular contacts, mediating the interaction of endothelium and the immune cells. The second issue, discussed in this article is a possible role of endothelial glycocalyx in the pathogenesis of preeclampsia—a complication of pregnancy associated with hypertension, proteinuria and edema. The reviewed data contribute a new insight in the endothelial dysfunction pathogenesis

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