Parametric x-ray radiation in the backward geometry

Parametric X-ray Radiation registered in the backward geometry is analysed. The main properties of the radiation for such geometry are discussed. The advantages of the backward geometry over other configurations regarding the intensity, the spectral width and the possibility to discriminate the contributions form different radiation mechanisms to the total radiation yield are presente

Evolution of the characteristics of Parametric X-ray Radiation from textured polycrystals under different observation angles

The Parametric X-Ray radiation (PXR) spectra and yield dependencies on the orientation angle are measured during the interaction of 7 MeV electrons with a tungsten textured polycrystalline foil for different observation angles. The effects of PXR spectral density increase and PXR yield orientation dependence broadening in the backward direction is shown experimentally for the first tim

Principales aspectos de la gestión del agua subterránea en un espacio periurbano del departamento Toay, La Pampa, Argentina

El trabajo caracteriza los principales aspectos inherentes a la gestión del agua subterránea en un es pacio periurbano, con viviendas carentes de redes de saneamiento y distribución de agua potable. Los indicadores urbanísticos muestran un sostenido proceso de ocupación, a partir de la transformación de un estilo residencial de ocupación temporaria en otro, de viviendas con uso permanente. Este escenario requiere ordenar el manejo del recurso hídrico subterráneo, para lo cual se implementó un programa de monitoreo que incluye mediciones de la fluctuación del nivel freático y toma periódica de muestras de agua subterránea. Los registros freatimétricos muestran una profundización del nivel freático mayor a 1 m, con una componente estival, atribuible a la intensificación estacional del bombeo. La caracterización hidroquímica muestra, dados los bajos valores de nitrato, que el acuífero aún no ha sido afectado por la disposición “in situ” de efluentes domiciliarios.The paper deals with some aspects inherent to groundwater management in a peri-urban area, without water supply and sanitation system. Urban indicators show an increasing housing development that requires an adequate groundwater planning. In that sense, began a monitoring program to obtain periodically measurements of water table fluctuations and groundwater samples. Piezometric record shows a downward trend of groundwater level with a seasonal component, related to an intensive exploitation during summer. Hydrochemical data, specially the low concentration of nitrate, indicates that aquifer is not yet contaminated with domestic wastewater.Universidad Nacional de La Plat

Diagnostics of nanodisperse polycrystals based on the polarization bremsstrahlung of relativistic electrons

The spectra of polarization bremsstrahlung are measured in the backscattering geometry during the interaction of 7 MeV electrons with a polycrystalline Ni foil. Measurement is conducted under condi tions such that the size of the region of coherent Xray radiation scattering in a target is on the order of 10 nm. The obtained results make it possible to suggest that using polarization bremsstrahlung as a new method for the diagnostics of the atomic structures of nanodisperse polycrystals is effectiv

Investigation of contactless electron transmission through dielectric channels

The effect of the contactless transmission (guiding) of 10 keV electrons through cylindrical dielectric channels and planar channels formed by glass platesis studiedyesBelgorod State Universit

Modeling of guiding of 10 keV electron beam by planar dielectric surface

Study of 10 keV electron beam reflection from a single planar dielectric surface was made. Guiding effect for some part of the beam was observed within grazing angles of incidence. Ionization, electron emission and drain of the surface charge were considered in the computer model to explain the result

X-ray studies of the distribution function of crystalline grains over orientation angles in mosaic crystals

The paper is devoted to theoretical and experimental studies of the new approach to X-ray diagnostics of mosaic crystals being proposed. The model of the scattering process on the crystals with the arbitrary distribution function of the crystalline grains over orientation angles is considered in detail. Experimental setup created on the base of this model is described as well as the first results of experimental studies conducted using highly oriented pyrolytic graphite with mosaicity 0.4 and 0.8 degrees

Parametric X-ray Radiation in the backward geometry

Parametric X-ray Radiation registered in the backward geometry is analysed. The main properties of the radiation for such geometry are discussed. The advantages of the backward geometry over other configurations regarding the intensity, the spectral width and the possibility to discriminate the contributions form different radiation mechanisms to the total radiation yield are presented.Аналізується параметричне рентгенівське випромінювання, зареєстроване в геометрії «строго назад». Обговорюються основні властивості випромінювання для такої геометрії. Представлено переваги геометрії «строго назад» у порівнянні з іншими геометріями в залежності від інтенсивності, спектральної ширини і можливості поділу внесків від різних механізмів випромінювання в загальний вихід випромінювання.Анализируется параметрическое рентгеновское излучение, зарегистрированное в геометрии «строго назад». Обсуждаются основные свойства излучения для такой геометрии. Представлены преимущества геометрии «строго назад» по сравнению с другими геометриями в зависимости от интенсивности, спектральной ширины и возможности разделения вкладов от различных механизмов излучения в общий выход излучения

Enhancement effects of transition and Vavilov-Cherenkov radiation mechanisms under grazing interaction of fast electrons with a thick substrate applied by thin layer

The paper presents the results of a theoretical study and a mathematical model of radiation processes occurred during the grazing interaction of fast electrons with semi-infinite targets applied on a thin amorphous layer. The developed model considers Vavilov-Cherenkov and transition radiation mechanisms and predicts the possibility to enhance the angular radiation density under grazing incidence of fast electrons on the layer. The characteristics of possible extreme vacuum ultraviolet and soft X-ray sources are estimate

Enhancement Effects of Transition and Vavilov-Cherenkov Radiation Mechanisms Under Grazing Interaction of Fast Electrons With a Thick Substrate Applied by Thin Layer

The paper presents the results of a theoretical study and a mathematical model of radiation processes occurred during the grazing interaction of fast electrons with semi-infinite targets applied on a thin amorphous layer. The developed model considers Vavilov-Cherenkov and transition radiation mechanisms and predicts the possibility to enhance the angular radiation density under grazing incidence of fast electrons on the layer. The characteristics of possible extreme vacuum ultraviolet and soft X-ray sources are estimated