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

Abstract

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 μm gaps and 13 μ 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 μm gaps between their neighbor surfaces was placed on goniometer. The 13 μm 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.