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The results of development work on experimental samples of small fission ionization chambers for recording fast neutrons (En ~ 1–20 MeV) in a reactor core are presented. A technological solution for obtaining a radiator based on ThO2 as a result of nonstationary low-temperature consolidation of an oxide coating from a solution of thorium carboxylate was developed and realized. Samples of ThO2-based radiators on the surfaces of multichannel electrodes of diameter 3 and 5 mm and coatings based on the isotope 238U (in the form U3O8 based on uranium with 235U content 0.00002%) were fabricated and small fission chambers based on them were assembled. Sample radiators were bench tested for stability during thermal cycling (15 cycles, heating to 750°C) and under vibration loads (to 200 Hz). Physico-mechanical and reactor tests of the fission chambers were conducted and the discrimination characteristics of samples and their sensitivity to heat and fast-neutron fluxes were determined. A comparative analysis of the conditions of effective application of small 238U- and 232Th-based fission chambers in long-time operation as well as in single neutron measurements is made.

The development of a new class of information and measurement systems with improved technical and metrological characteristics for prolonged operation during external perturbations (high temperature, pressure, radiation, seismic, electromagnetic, vibration, and other loads), which are characteristic for special-purpose power installations and units of NPP is discussed.

A method of synthesis of metal oxide films by carboxylate pyrolysis on a substrate surface is developed. The optic physical properties of the obtained films are studied by spectrophotometry using specialdesign fiber-optic probes.

Technological processes are developed for fabricating fluoride glass products with the use of different molding methods, such as free molding, controlled molding, mechanically activated injection molding, and forced molding at low temperatures and high pressures. A multimodule facility is designed for fabricating fluorozirconate, fluorohafnate, and fluoroaluminate glass products in the form of disks, plates, cylinders, blocks, tubes, rods, and optical fibers. Fluoride glass products are intended for the use in multifunctional multifiber systems for transmitting molecular, thermal, and other types of information.

Heating of fluoride stock was analyzed. A module for drawing fluoride stock into optical fibres was developed. The transient responses and transmitting functions of the object of control in “current strength—temperature” and “gas flow—temperature” channels were obtained. The structure of a system for controlling heating of fluoride stock was proposed based on the results of the study.

The properties of polycrystalline optical fibers produced by extruding crystals of AgCl1−x Brx(x = 0.5–0.8) solid solutions are studied by optical microscopy, scanning electron microscopy, microstructural analysis, and x-ray microanalysis. The results demonstrate for the first time that the arrangement of polycrystalline regions and recrystallized single-crystal blocks 0.03-–0.10 and 2–5 µm in size, respectively, possesses three- or fourfold symmetry or a mirror plane m, depending on the crystallographic orientation of the parent crystal (cubic symmetry). The effect of the structural properties of the parent crystal on the properties of the fibers is discussed.

The properties of AgCl1 − x Br x ( x = 0.5–0.8) solid solutions prepared by the Bridgman-Stockbarger method are studied using a variety of techniques (x-ray diffraction, microstructural examination, chemical analysis, and x-ray microanalysis). The lattice parameter of the solid solutions is found to exhibit a negative deviation from additivity. The effects of composition and preparation conditions on the structural properties of the solid solutions are discussed. The structural characteristics of abrasively polished surfaces of the samples are shown to be influenced by the preparation conditions.

Fluoride glasses, for the production of IR optical fibers, have a tendency to crystallization. The crystallization of fluoride glasses is one of the main reasons for non-intrinsic optical losses due to scattering in fibers. The crystallization kinetics of 53ZrF4–20BaF2–4LaF3–3AlF3–20NaF (ZBLAN), 53.8HfF4–20.1BaF2–5CeF3–3.1AlF3–17NaF–1.2InF3 (HBCANI), 12.3BaF2–12.3SrF2–12.3CaF2–12.3MgF2–36AlF3–12.3YF3–2.5LaF3 (BSCMAYL), 30InF3–10YF3–25BaF2–5SrF2–10ZnF2–10GaF3–6NaF–4PbF2 (InYBSNZnGaPb) fluoride glasses was investigated at the early stages of glass-to-crystal transformation. The experiment consisted in measuring the contents and sizes of microcrystals in glass interiors as a function of treatment time of the sample at constant temperature. The contents and sizes of crystals were determined by the method of laser ultramicroscopy. Investigations were carried out in the range between glass-forming and softening temperatures. The nucleation rate, W, the linear growth rate of crystals, V, and the temperature dependence of these kinetic parameters were found at the level of conversion of glass-crystal between 10−6% and 10−3%. The nucleation rate was maximum of ∼200 nuclei /( s cm 3 ) near 260°C in ZBLAN, ∼300 nuclei /( s cm 3 ) near 280°C in HBCANI, ∼280 nuclei /( s cm 3 ) near 400°C in BSCMAYL and ∼650 nuclei /( s cm 3 ) near 310°C in InYBSNZnGaPb glass. The results of investigation are useful for optimization of the heat treatment mode of fluoride glasses and to understanding of the processes critical to the optical homogeneity of these glasses.

The separation coefficients of ZrF4(HfF4) and metal fluoride impurities in the process of vacuum sublimation between 900 and 1200 K in the molecular vaporization regime were calculated. The separation coefficients were found to decrease in the order CrF2> MnF2> NiF2> CoF2> MnF3> FeF2> AlF3> CrF3> CuF2> FeF3 . The conditions for purification of ZrF4and HfF4by vacuum sublimation were optimized. The total impurity content in both fluorides was found to increase with the product of the evaporation rate per unit area and the degree of evaporation. Fe was found to be the most difficult-to-remove impurity in ZrF4and HfF4 . The production rate of the sublimating plant is about 100 kg/year of ZrF4and HfF4sublimates. ZrF4was used to prepare optical fibers for laser applications and noncontact fiber sensors for monitoring the composition and temperature of liquid radioactive waste. Fluorohafnate glasses were used to fabricate radiation-resistant scintillating modules of dimensions 20 × 30 × 150 mm, weighing ≤0.5 kg.

The results of physical and material science and technological development of new materials of radiation photonics - nano- and microstructure of radiation-sensitive and radiation- resistant optical glass and fibers based on quartz are presented in the report. The possibility of their application in neutron diagnostics devices of nuclear power objects are considered. Component and construction options for the radiation-sensitive fiber and glass materials (with isotopes 10B, 6Li, Gd, ions of Nd3+, Ce3+ etc.), in which radiation resistance is achieved through the organization of areas of "drain" and annihilation of radiation-induced defects are considered.

Radiation-induced changes in the optical properties of fluoride glasses (FGs) were studied on samples of zirconium fluoride and aluminum fluoride based compositions gamma-irradiated to a total dose of 1.2 MGy. Upon exposure, the fundamental absorption edge smears and shifts toward longer wavelengths. The FGs studied exhibit self-recovery of the optical properties, whereby the radiation-induced absorption decreases in the course of storage without action of any external factors. Photostimulated recovery of the optical properties of the gamma-irradiated FGs was studied in the range of light wavelengths from 400 to 1200 nm at a light intensity of 1–3 mW/cm2. The maximum rate of recovery for both zirconium and aluminum fluoride based glasses was observed for the photoannealing at 600 nm.