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.
Parametric X-ray radiation produced during the interaction of charged particles with polycrystals is regarded. A review of the existing theories, perspectives of application and performed experiments is presented. The evolution of experimental capabilities as well as the progress in the process comprehension is illustrated. The state of the art of PXR in polycrystals is presented.
The Röntgen-1 setup which is intended for use in investigating the spectral-angular characteristics of X-rays generated due to the interaction between a 7-MeV electron beam and substances, including different shaped surfaces, is described. The setup is distinguished by a low radiation background, enabling the determination of low-intensity radiation spectra. The results of measuring the characteristics of the polarized bremsstrahlung of relativistic electrons from media with different atomic structures are presented.
A set of experiments to study the guiding of 10keV electrons by tapered glass capillaries was performed. It is shown that the 10keV electron beam can be tightly focused by the tapered macrocapillaries. The charge/discharge processes of the capillary inlet are shown and discussed. The guiding effect was obtained for 10keV electrons by a tapered glass capillary of a simple shape. The electron beam transmission was measured for several angles.
The collimated spectra of polarization bremsstrahlung (PB) produced by 7MeV electrons in Al, Ni, Cu, Mo and W poly crystalline foils are measured and the angular dependences of the PB characteristics are studied. A comparison of the experimental results with theoretical predictions is performed. Polarization bremsstrahlung sensitivity to texture and grain size of the target in the backscattering geometry is shown. The possibility of developing a new method based on the characteristics measurement of the coherent PB component for the diagnostics of polycrystalline materials is considered.
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 conditions such that the size of the region of coherent X-ray 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 effective.
For the first time a classical model was developed to describe quantitatively the dynamics of charge distribution formation on a planar dielectric surface during its irradiation by fast electrons at a grazing incidence. The dynamic effects of the mutual influence of the beam and the dielectric surface charge predicted by the developed model are in a good agreement with the performed experiments. The proposed model can be used to describe time dependent processes of the electron beam–dielectric surface interaction, charging up and discharging for dielectric channels of more complex shapes.
Исследуется эффект бесконтактного прохождения (guiding) электронов с энергией 10 кэВ в диэлектрических цилиндрических каналах и плоских каналах, образованных стеклянными пластинами. В экспериментах с двумя пластинами наблюдались обычные в таких случаях захват и распространение электронного пучка вдоль оси канала. Исследование отражения пучка от одной пластины выявило отклонение угла отражения от зеркального и зависимость характера отражения от длины пластины и величины тока.
The effect of the contactless transmission (guiding) of 10 keV electrons through cylindrical dielectric channels and planar channels formed by glass plates is studied. The capture and propagation of an electron beam along the channel axis, usual in these cases, are observed in the experiments with two plates. The deviation of the reflection angle from the specular angle and its dependence on the plate length and beamcurrent value under beam reflection from a single plate are investigated.
The spectrum of polarization Bremsstrahlung is measured in backscattering geometry for 7-MeV electrons and a polycrystalline Ni foil without texture. The average size of grains in the foil is 300 nm. The results show the possibility of using a new method in the diagnostics of the atomic structure of polycrystalline materials with nanosized grains. The method is based on measuring the coherent component of polarization Bremsstrahlung.