Bekhzodjon Abdurahmonovich Abdurakhimov

As the methods, instrumentation, and resolution of three-dimensional spatial analysis have improved over the past twenty years, it is now possible to image the internal microstructure of multiphase materials in detail in three dimensions. Three-dimensional X-ray microtomography offers a unique opportunity for high spatial resolution imaging that can be achieved in compact desktop systems using X-ray microfocus sources. Recently, a modern desktop cone-beam X-ray microtomography system for quantitative analysis of materials in three dimensions was installed at the Institute of Nuclear Physics of the Ministry of Energy of the Republic of Kazakhstan. This paper presents the design, description of the main components, and technical parameters of this X-ray microtomography system, called IMAX. This system is designed to acquire, process, store X-ray images, and reconstruct three-dimensional data from angular projections for the study of internal structures and non-destructive testing of materials. The system consists of a microfocus X-ray source providing an X-ray energy range from 35 to 80 keV, a flat panel scintillation detector system allowing high-resolution digital imaging, optomechanical platforms for sample positioning, and radiation shielding. The first results of test measurements using this X-ray system are presented.

Our paper presents the preliminary results of the measurement of some ceramic fragments that come from the archeological excavations from the settlement that was formed around the castellum of the stone vallum, from Constanța. These ceramic artifacts date from the Byzantine period (10th-11th centuries).

The systematic studies of composition and spatial distribution of main phases inside volume of 25 fragments of Byzantine ceramic obtained in archeological works in the Dobrudja region, Romania, have been performed using neutron diffraction and tomography, and Raman spectroscopy. The obtained structural data on the content of phases, the presence of calcite grains and pores, and the uniformity of phase spatial distribution made it possible to systematize the studied fragments and correlate them with clay sources or pottery workshop. The experimental possibilities of neutron methods of nondestructive structural diagnostics as well as the structural markers provided by them in the studies of ceramic samples are discussed.

The rock fabric of two lamprophyre dike samples from the Koy-Tash granitoid intrusion (Koy-Tash, Jizzakh region, Uzbekistan) has been studied, using the neutron tomography method. We have performed virtual segmentation of the reconstructed 3D model of the tabular igneous intrusion and the corresponding determination of dike margins orientation. Spatial distributions of inclusions in the dike volume, as well as further analysis of size distributions and shape orientations of inclusions, have been obtained. The observed shape preferred orientations of inclusions as evidence of the magma flow-related fabric. The obtained structural data have been discussed in the frame of the models of rigid particle motion and the straining of vesicles in a moving viscous fluid.

The structure and spatial distribution of corrosion in the volume of the medieval Qarakhanid dirham dated the X–XII century A.D. (Anno Domini) has been investigated using non-destructive structural X-ray diffraction and neutron tomography methods. The phase composition and their spatial distribution inside the coins were obtained. The main phase of the studied dirham is the silver-copper alloy with copper fraction dominance up to 74 wt %. The basic phases of the corrosion fraction are cuprite Cu₂O, tenorite CuO and chalcocite Cu₂S. The non-uniform distribution of the corrosion penetration in the coin bulk was constructed.