Yu.A. Gaponov

Fast, parallax-free, one-coordinate X-ray detector OD3

Abstract A second version of fast, parallax-free, one-coordinate X-ray detector OD3.2 destined for X-ray diffraction experiments is presented. The construction, basic principles of operation, results of the test with isotopic source 55Fe and X-ray beam test are being discussed.

THE STATION FOR TIME-RESOLVED INVESTIGATION IN WIDE AND SMALL ANGLES OF DIFFRACTION

Abstract The description of the experimental station installed on 5-b th beam line of VEPP-3 storage ring (Budker Institute of Nuclear Physics SB RAS, Novosibirsk) is presented. The synchrotron radiation (SR) from viggler generating 2 beams is used. The station is intended for X-ray diffraction research of various biological objects and other materials in small and wide diffraction angles.

Structure changes in the sol–gel systems of hydrated oxides

This work was undertaken partly with financial support of the RBRF of the Ministry of Science of the Russian Government (N95-03-09682a) and partly with financial support of the Ministry of Education, Science, Sports and Culture (MONBUSHO) of the Government of Japan.Sols of hydrated aluminium oxide, hydrated zirconium oxide and their mixtures were investigated during the xerogel-amorphous-product-crystalline-product transition by SAXS using synchrotron radiation. In the different temperature regions certain changes in structure and morphology were observed. Some correlation between the characteristics of the initial sols and their mixtures (the size and shape of the pores) was observed. In the temperature region 298-1173 K the characteristics of the mixed sol are defined by the characteristics of the initial sols.

A station for studying solid-state chemical reactions by the Laue method

Abstract A station for studying solid-state chemical reactions by the X-ray diffraction Laue method is described. A two-coordinate position-sensitive X-ray detector is used as the registration device. In the reaction chamber the sample is kept at a controlled temperature and under pressure of a gaseous atmosphere (or vacuum). The possibility of investigating the kinetics during solid-state chemical reactions is shown for the example of crystal hydrate dehydration in vacuum.

Thermal decomposition of crystal hydrates by the Laue method

A method is developed to study the reaction interface during thermal decomposition topochemical processes. Requirements and limitations imposed on this method are considered. The possibility of using the synchrotron radiation space-resolved diffractometry method for solving solid-state chemistry problems is shown for an example of dehydration of the crystal hydrate CaSO4∗2H2O. A computer simulation is proposed for the interpretation of changes in the reaction interface.

A study of the sol-gel process of sols of hydrated oxides by SAXS using synchrotron radiation

Abstract Sols of some electrochemically produced hydrated oxides (original sols) and their mixtures (binary sols) are studied by SAXS using synchrotron radiation (SR). The presence of 1–2 nm scattering entities (primary particles) is a characteristic property of the investigated sols. During gelation and concentration of the original sols the interparticle distance varies in different ways. The binary sols gelate without concentration of the system. Particles with different sizes are observed in the binary sols. It is possible to separate two sections (time intervals) on the kinetic curves of the structural parameters concerning the changes in the binary sols.

Portable high precision small/wide angle X-ray scattering diffractometer

AbstractTheportablehighprecisionsmall/wideangleX-rayscatteringdiffractometer(modifiedBonze–Hartopticalscheme)was designed and developed for the investigation of structure rearrangement during liquid state–solid statetransformations (with reaction time of 10h or more) for the investigation of the process of solid state phaseformation.TheFEMdetectorsareusedasmonitoranddetector.ThedoublecrystalSi 111 analyzer(withchangeablerelative angle of the second crystal) is used as analyzer. All controlling electronics are designed in CAMAC. ThediffractometeriscontrolledbyaSunSPARCStationwithSVIC/VCCmodulesunderaSolaris2.4operatingsystem,and allows one to obtain the SAXS curves with accuracies (on s-vector for photon energy 8keV) of aboutds 0.002nm 1 , s min 0.005nm 1 (scattering centers with the size of about 200–500nm may be observed) ands max 50nm 1 (scatteringangleisabout808).# 2001ElsevierScienceB.V.Allrightsreserved. PACS:07.85.Qe;07.85.Jy;07.05.Hd;07.85.KfKeywords:Synchrotronradiation;SAXS;Diffractometer;Dataacquisition;Dataanalysis

Comparative study of the structure rearrangement in mixed and binary Zr–Ti sol–xerogels ☆

Abstract Structure rearrangement during gelation and thermal decomposition of the Zr/Ti sol–xerogels, chemically identical but prepared by different methods (mixed and binary), was studied by SAXS/WAXD with the use of SR. Observed, primary, particles in the systems under investigation in the sol state differ both in size and in shape. In the case of a mixed sol, a primary particle consists, probably, of a particle of hydrated titanium dioxide surrounded by particles of hydrated zirconium dioxide. In this case, during gelation the primary particle changes to a much smaller particle. In the case of a binary sol the primary particle is a complex Zr–Ti particle and changes insignificantly during the gelation. During the thermal decomposition of both xerogel systems, the formation of the final product (titanium zirconium oxide) goes through the mechanism of nucleation and growth of the new phase.

Object library for a new generation of experiment-controlling applications under the UNIX operating system.

The Interface Object Library based on the Motif extension of the X Windows system and on the ESONE SVIC-VCC Library is presented. Some features of the applications for controlling a synchrotron radiation experiment are discussed. The Interface Object Library is written in the object-oriented C++ language. The library class-hierarchy structure is presented and discussed. Several interfaces were realized in the Interface Object Library: the Windows interface, the CAMAC interface and the interface for supporting the experiment. The behaviour of the objects describing the CAMAC crate and CAMAC block is discussed. The application of these protocols for controlling the fast one-coordinate position-sensitive X-ray detector OD3 is presented.

Position sensitive x‐ray detector OD‐3

A fast one‐coordinate x‐ray detector of a new design aimed for angular measurements in diffraction experiments was developed in BINP. The detector is based on a multiwire proportional chamber with x‐ray absorption drift volume. It allows acceptance of photons in the energy range from 6 keV to 20 keV with a maximum rate of 10 MHz/detector and coordinate resolution about 0.1 mm (rms) in linear scale. The first OD‐3 chamber has a 0.4‐mm‐thick Be inlet window 200 mm x 10 mm, a photoabsorbtion length of 50 mm, and a parallax‐free cathode structure for angles up to ±15 degrees at variable focal length (from 300 mm to 450 mm without any modification and to infinite at cathode plane replacement). The first tests of the detector at synchrotron radiation beamline 5‐b VEPP‐3 and with a x‐ray tube show a good performance. The detector construction specifics and test results will be discussed in the report.