E. S. Kovalenko

Multimode X-ray tomography at the mediana Station of the Kurchatov synchrotron radiation source

The synchrotron radiation used in X-ray tomography enables us to vary the recording conditions within wide limits due to the continuous spectrum and the beam’s high brightness and collimation. The possibilities of multimode X-ray tomography at the Mediana station of the Kurchatov synchrotron radiation source, including tomography and microtomography based on white and “pink” beams, imaging with the help of a monochromatic beam, and measurements via axial and refractive phase-contrast methods, are described. The presented results of the reconstruction of different objects have been obtained under different recording conditions.

Synchrotron and Neutron Tomography for the Investigation of Paleontological Objects

X-ray microtomography is used to study the internal structure of paleontological objects, but there are disadvantages of the method which greatly limit the effectiveness of the research. Therefore, in this work tomography using thermal neutrons and synchrotron radiation is applied to study the internal structure of paleontological objects. It is shown that neutron tomography makes it possible to distinguish between minerals and rocks, which can not be distinguished using X-rays. Refraction tomography using synchrotron radiation reveals structures indistinguishable by the standard method. An advantage of imaging using synchrotron radiation and thermal neutrons is shown using some examples of paleontological objects. The prospects of the application of neutron and synchrotron methods to paleontology are discussed.

Observation of small-angle contrast in refraction introscopy via full angular scanning

In this paper we describe experiments in an imaging scheme with two perfect crystals which demonstrate the possibility of using the full angular scanning of images by means of a crystal analyzer for separating absorption, refraction, and small-angle scattering in image formation. The possibility of determining the characteristics of heterogeneous objects using this method is discussed.

A neutron tomograph at the IR-8 reactor of the National Research Centre Kurchatov Institute

A transmission neutron tomograph developed by the National Research Centre Kurchatov Institute is described. The tomograph is located at the monochromatic neutron beam of the fifth horizontal channel of the IR-8 research reactor. The neutron wavelength is 1.56 Å, the beam cross section is 50 × 40 mm2, the field of view of the CCD-based detector system is 93 × 62 mm2, and the spatial resolution at the sample position is ∼400 μm. The internal structure of samples having different origin has been investigated.

Synchrotron and Neutron Tomography of Paleontological Objects on the Facilities of the Kurchatov Institute

The most important results of tomographic studies of paleontological objects on the facilities of the National Research Centre “Kurchatov Institute” are described. It is shown that the use of the synchrotron and neutron tomography makes it possible to obtain new information on the structure of fossil animals, which is of fundamental importance for taxonomy and morphological analysis of extinct fauna.

Study of Bronze Statues “John the Baptist” and “Dancing Cupid” from the Collections of the Pushkin State Museum

Bronze statues “John the Baptist” and “Dancing Cupid” from the collections of the Pushkin State Museum of Fine Arts have been investigated at the National Research Centre “Kurchatov Institute.” These statues were previously damaged in fire. Before carrying out restoration, it was necessary to perform their complex study, including identification of statue materials; elemental and phase analysis of contaminations; estimation of the state of surfaces and internal parts; and detection of technological elements, as well as hidden defects, corroded parts, and cracks. To this end, scanning electron microscopy with X-ray microanalysis, synchrotron radiation diffraction, and neutron radiography and tomography have been used.

A method for obtaining 3D images of a sample by detecting scattered X rays with a pinhole camera

A method for studying the internal structure of a sample by detecting scattered synchrotron radiation using a pinhole camera is considered. The beam for imaging is shaped like a plane that intersects the sample. The characteristic spatial resolution of the method is 100 μm. Examples of the obtaining of images are presented, and the differences of this method from traditional techniques are discussed.

Study of the structure of synthetic opals affected by temperature and pressure

It is demonstrated that synthetic opals, like most natural ones, have a cristobalite rather than quartz basis, change their color from white to blue after losing their water-containing component, and form superlattices. Being affected by temperature and pressure, they undergo partial or complete crystallization to the corresponding polymorphic modifications.