Microfocus Bremsstrahlung Source Based on a Narrow Internal Target of a Betatron

The paper addresses the research into the properties of bremsstrahlung generated by interaction of the internal electron beam of the 18 MeV betatron with narrow targets, 50 and 8 μ m thick Si crystals and 13 μ m thick Ta foil with a length of 4 mm along the electron beam, mounted in the goniometer inside the betatron chamber. The radiation beams generated in the targets were used to obtain the images of a microstructure of thin wire pairs and an object that consisted of four steel bars with 10 μ m gaps between them. The images indicate high absorption contrast of their components due to a small horizontal size of the radiation source the width of which in the cases of Si crystals and Ta foil was 30-, 187- and 115-fold smaller than the diameter of the electron beam, respectively. The edge phase-contrast was also observed due to high spatial coherency of the radiation with the linear microfocus generated in the source based on the B-18 betatron with a narrow target inside.