Simulation of the Betatron Magnetic Field at the Electron Beam Displacement in Comsol Multiphysics

This article describes the betatron magnetic field simulation in Comsol Multiphysics software package. The model makes it possible to evaluate the betatron focusing properties at the moment of electron displacement onto the target. The simulation results coincide with the experiment described earlier. The study shows the vertical size of the target affects the focal spot size. However, a target size decrease leads to low output dose, since not all electrons reach it. Therefore, the vertical size of the target should be greater than or equal to the vertical dimension of the accelerated beam

X-ray tomography of the aerospace products

Currently, non-destructive methods are increasingly being used to inspect the critical components in different branches of industry. Special focus is on the usage of high-energy X-ray microtomography used to inspect large objects with high density. This method provides high accuracy and a possibility to measure the internal and external dimensions of the test sample without its destruction. It allows obtaining the information about internal defects and damages as well as manufacturing and assembling quality. This article describes a tomographic study of a medium-size high-density sample with a resolution about of 70 microns

Observation of refraction-contrast effect in images obtained with microfocus bremsstrahlung gamma-rays generated in a narrow internal target of 18 MeV betatron

The first results of experiments demonstrating refraction contrast in magnified (x2.5) images obtained using the Bremsstrahlung gamma radiation of 18 MeV betatron with a narrow tantalum (Ta) target inside are presented. The Ta foil-target with a thickness of 13 urn and a length of 4 mm along the electron beam was mounted in a goniometer inside the chamber of the betatron to guide her along the electron beam. In this case, a linear microfocus source of Bremsstrahlung gamma radiation with vertical and horizontal dimensions of 1.5 and 0.013 mm, respectively, is realized for direct-forward emission of radiation. The obtained magnified images of rectangular steel plates with thicknesses in the region of 15-0.3 mm and lead foils with thickness of 25 urn demonstrated a high resolution of their edges due to the refraction contrast effect, which is realized due to the refraction of microfocus gamma radiation on the surfaces of the lateral faces of the samples

Detectability of flat microdefects in radiographic images obtained using linear microfocus bremsstrahlung source based on 18 MeV betatron with narrow target inside

For the determination of ability of microfocus Bremsstrahlung (Bs) source based on B-18 betatron to detect flat microgaps and microinclusions in heavy material products the investigations were carried out. The radiographic images of 10 [mu]m gaps and 13 [mu] m tantalum (Ta) foil into steel bulk which were oriented at different angles with respect to the direction of radiation were investigated. The assembly of four steel blocks having 10 [mu]m gaps between their neighbor surfaces was placed on goniometer. The 13 [mu]m Ta foil having the length of 4 mm along radiation beam was mounted in a plastic holder which was also placed on the goniometer. For modeling narrow gaps and thin inclusions inside the bulk of steel detail, the experimental samples were placed before a thick steel plate. The radiographic images of the samples were obtained with a 2.4-fold magnification at different orientations of narrow gaps and Ta foil with respect to the radiation beam and at the thick steel plates of different thicknesses. The results illustrate high sensitivity of detecting of the microgaps inside steel bulk and flat microinclusions from heavy material in the bulk of detail made from a lighter material due to the microfocus of Bs source

Effect of Preliminary Irradiation of 321 Steel Substrates with High-Intense Pulsed Ion Beams on Scratch Test Results of Subsequently Deposited AlN Coatings

The paper presents the effect of irradiation of 321 steel substrates with a high-intense pulsed ion beam (HIPIB) on changes in functional properties of the surface layers and tribological characteristics of AlN coatings subsequently deposited above by the reactive magnetron sputtering method. The morphology of the modified surface layers, their microhardness and free surface energy levels are presented for different HIPIB energy densities. HIPIB irradiation of the substrates caused variations in the results of scratch tests combined with the acoustic emission signal processing. Their analysis has enabled concluding that the crack initiation threshold could be at least doubled for the studied coating/substrate system due to preliminary HIPIB irradiation. Finally, the obtained data were discussed, and future research directions were proposed

New microfocus bremsstrahlung source based on betatron B-18 for high-resolution radiography and tomography

New microfocus source of hard bremsstrahlung (photon energy > 1 MeV), based on the betatron B-18 with a narrow Ta target inside, for high-resolution radiography and tomography is presented. The first studies of the source demonstrate its possibilities for practical applications to detect the microdefects in products made from heavy materials and to control gaps in joints of parts of composite structures of engineering facilities. The radiography method was used to investigate a compound object consisting of four vertically arranged steel bars between which surfaces were exposed gaps of 10 [mu]m in width. The radiographic image of the object, obtained with a magnification of 2.4, illustrates the good sensitivity of detecting the gaps between adjacent bars, due to the small width of the linear focus of the bremsstrahlung source