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The issue presents the results of studies of methods for increasing the corrosion resistance of fuel claddings made from zirconium alloy E110, performed at the SRC RF TRINITI, using coatings (Al, Al2O3, Cr) by pulsed laser deposition, as well as magnetron sputtering and galvanic deposition of chromium. Also presented some results of studies of adhesion, microstructure and corrosion resistance of chromium coatings deposited by various methods. It was revealed that the corrosion resistance of the cladding of fuel rods with chrome coatings at temperatures of 1100 – 1200 °С practically does not depend on the method of their application. However, the coating method has a significant effect on their adhesion, with coatings obtained by atomic deposition methods and characterized by a continuous uniform structure have the greatest adhesion. The depth of oxidation of the outer surface of the cladding of a fuel rod when applying a chromium coating decreases by an average of 30 times for sponge-based alloy E110.

The deficiencies of existing standard iron and nickel samples for calibration by means of X-ray diffraction are noted. These standards cannot be used in calibration by magnetic noise recording. A new calibration method based on X-ray diffraction is proposed, using plane samples of the material employed in the manufacture of the actual structures. Theoretical analysis provides the basis for the development of null standards in which a plane sample is deformed by pure flexure or in a cantilever-beam configuration.

The existing excimer lasers with pulse durations in the nanosecond range and high pulse and average power afford a unique possibility of influencing the surface of materials and developing new, efficient technologies. It is shown in this article that surface treatment with a periodic-pulse UV laser cleans surfaces by removing oxides, reduces roughness, and increases hardness. Different variants of pulsed laser deposition of aluminum and Al2O3 are used to form protective, composite, cermet layers that suppress surface corrosion of EP-823 steel fuel-element cladding in lead in contact with air at 650–720°C.

The created experimental magnetron sputtering system allows preliminary cleaning of the substrate surface and subsequent deposition of coatings on long cylindrical products within a single system using a coaxial magnetron discharge at a working gas pressure of 150 mTorr. The coating discharge has reverse electrodes polarity relative to the cleaning discharge. A theoretical calculation of the discharge parameters has been carried out.

The treatment conditions of fuel claddings of the E110 alloy by using powerful UV or IR laser radiation, which lead to the increase in the corrosion resistance at the high-temperature (T = 1100°C) oxidation simulating a loss-of-coolant accident, are determined. The possibility of the complete suppression of corrosion under these conditions by using pulsed laser deposition of a Cr layer is demonstrated. The behavior of protective coatings of Al, Al2O3, and Cr planted on steel EP823 by pulsed laser deposition, which is planned to be used in the BREST-OD-300, is studied. The methods of the almost complete suppression of corrosion in liquid lead to the temperature of 720°C are shown.

In this paper the application technology of the ultrasonic testing method in the process of the PS-90A aircraft engine manufacturing is considered. It is known that the development and implementation of monocrystalline turbine blades for aircraft gas turbine engines are aimed at ensuring the material effectiveness or increasing the blade service life in comparison with polycrystalline blades. It is achieved at the cost of the increased long-term material strength in the same temperature range. Based on the results of the process and metallographic studies analysis, it has been established that during the structure formation under the internal stress action, hot crystallization cracks with an opening from 3 to 8 μm or more and a length of 3 to 35 mm along the grain boundaries can appear. Grains formation in most blades happens with their subsequent exit to the lock end, a bridge. The formation of hot cracks most likely occurs at a large grain disorientation angle (more than 25°). Grain boundaries on blades with hot crystallization cracks are located, as a rule, on the bridge at the junction of the blade root with the blade shank (“bottleneck”) with orientation along the blade axis. The method of contact laser-ultrasonic flaw detection (CLUFD) was tested on blades in the region of bridges using both pilot samples and standard parts in order to solve an urgent production and technical problem, that is timely detection of hot crystallization cracks in rotating turbine engine blades at the manufacturing stage. The use of the phased antenna array technology (PAR) in combination with a portable X-32 flaw detector represents a new level of blade ultrasonic testing. The flaw detector operates in a wide frequency range, which allows solving a very large range of various ultrasonic testing problems. The advantages and possibilities of the PAR technology with the portable X-32 flaw detector can be considered on the example of the turbine blade lock testing. S-scan (sector-scan) makes it possible to interpret the received signals quickly and easily.

The work is devoted to the study of the influence of the parameters of ultrasonic shot peening on the physicomechanical properties of the surface layer of flat samples of 08ps steel, AMg2 and M2 alloys. The results of determination of residual stresses, microhardness are given. As a result, it was established that the processing time makes the largest contribution in the selected modes.

A helium-3 adsorption refrigerator cooled with a pulse-tube cryocooler is developed. The refrigerator has two stages of adsorption pumping. The first stage is designed for the condensing and pumping of helium-4, whose cooling capacity is used for the condensation of helium-3. The second stage is designed for pumping helium-3. The final temperature reached by the refrigerator is 0.305 K. This temperature is retained for at least 24 h. The time required for helium recondensation and the obtainment of low temperature is 1.5 h. The cryostat is a self-contained instrument, as it contains no external gas-supply pipelines and the working gas is stored directly within the working volume of the refrigerator. The work is performed in the Frank Laboratory of Neutron Physics of the Joint Institute for Nuclear Research.

Analytical expressions for the calculation of drawing stress and the optimal channel angle of the drawing tool, making it possible to operatively evaluate the influence of various manufacturing factors on the energy-power parameters of the process and on the longitudinal stresses in the layers of bimetallic composite, are derived for designing the drawing process of bimetallic wares. Disadvantages of the proposed formulas are noted.

When designing the drawing process of sections with a regular polygon profile, it is convenient to use analytical expressions that make it possible to operatively evaluate the effect of different manufacturing factors. A calculation procedure for stress in this process is proposed. The relationships are derived for the calculation of the drawing stress, the optimal angle for the drawing-tool channel, the limiting deformation rate with the use of a standard tool, and the stress-state characteristic in the axial part of the deformation zone. The application of a drawing tool with optimum angles decreases the accumulation rate for defects of the metal structure and makes it possible to decrease the number of intermediate thermal treatments during multiple drawing.

The process of drawing rectangular sections is conveniently designed with the use of analytical expressions that make it possible to operatively evaluate different manufacturing factors. The application of a drawing tool with optimum angles makes it possible to cut down power inputs and reduce the failure and unsoundness of a blank. A design procedure for the drawing stress of the rectangular section is advanced. Formulas for calculating the drawing stress and determining the optimum angles of a channel of the drawing tool are derived. It is shown that the optimum angles depend on the friction coefficient and the reduction ratio.

In the design of metal forming processes it is widely used to obtain a linear model of damage accumulation and scalar failure criterion. The process of plastic deformation can be described by the kinetic equation of nonlinear dynamics for systems with a strong positive correlation. This paper considers the failure criterion and condition of deformation without destroying in multi-step process of plastic deformation. Check of applicability of criterion showed that it can be used for solving practical problems of processing of metal forming processes.

The design of a compact ultrahigh-vacuum nitrogen-free helium cryostat is described. The volume of the helium vessel of the cryostat is 2.7 l, and the time of operation after filling it with liquid helium is >65 h. The cryostat satisfies the requirements imposed on ultrahigh-vacuum systems, allows heating to 200°C, and ensures operation at an evacuation level of 10−10 Torr.

Time differential perturbed angular gamma-gamma-correlation (TDPAC) method on 111Cd nuclei probes inserted in ZrZn1.9 is used to measure the magnetic hyperfine fields (MHF) at Zr and Zn sites and the electric field gradient (EFG) Vzz at Zn sites as a function of temperature at various pressures and as a function of pressure at the temperature 4 K. Our data indicate that the local magnetic moment of Zr in the magnetically ordered state is substantially larger than its value obtained from the macroscopic measurements and that there is also an induced magnetic moment at the Zn site. We conclude that ZrZn2 is not a simple ferromagnet and discuss a possible type of its magnetic ordering., 7 pages, 6 figures, submitted for publication

100-g silicon detectors (known as “ZIPs,” Z-resolving Ionization and Phonon detectors) developed by the Cryogenic Dark Matter Search Experiment have been tested at charge bias voltages of up to 200 V/cm, significantly above their usual operating range (∼3–6 V/cm). Thermal gain factors in excess of 50 were observed due to the primary ionization drifting in the large applied field, with only minimal increase in phonon noise. The observed thermal gain corresponds to an intrinsic threshold of 20 eV, resulting in detectors that have direct application for use in a neutrino magnetic moment measurement based on a 40-MCi tritium source.

An experiment aimed at directly detecting antineutrino-electron scattering by using a 40-MCi tritium β-active source will make it possible to lower the present-day laboratory limit on the neutrino magnetic moment by two orders of magnitude. The experiment brings together novel unique technologies in studying rare processes of neutrino-electron scattering: (i) an artificial source of antineutrinos from tritium decay of 40-MCi activity with the antineutrino flux density of about 6×1014 cm−2 s−1 and (ii) new types of detectors capable of detecting electrons of energy down to about 10 eV, namely, a silicon cryogenic detector based on the ionization-into-heat conversion effect and a high-pure germanium detector with an internal signal amplification in the electric field. A compact installation located at a specially equipped underground laboratory (≤100 mwe) will provide favorable background conditions for running the experiment. With a background level of about 0.1 event/(kg keV d) and detector assembly masses of 3 and 5 kg for the silicon and germanium ones, respectively, a limit of μ ν ≤3±10− μ B on the electron-antineutrino magnetic moment will be obtained within 1 to 2 years of data acquisition. The status of the experiment and the state of the art are presented.

The compound CaCo2 with the C15 cubic Laves phase structure and an estimated density of 5.21 g/cm3 has been synthesized at 8.0 GPa pressure. Magnetization measurements showed that the compound CaCo2 is a ferromagnet with Curie temperature 528 K and magnetic moment per Co atom 1.75 μB at T=4.2 K. LMTO calculations of the electronic band structure showed that CaCo2 forms as a result of an s-d electronic transition of Ca and in the ground state it is a ferromagnet with a high magnetic moment per Co atom.

A study is made of the temperature and field dependences of the anisotropic magnetization of a quasi-one-dimensional charge-density-wave conductor — the blue bronze K0.3 MoO3. Nonlinearity of the magnetization curves is observed at temperatures below 100 K. The temperature and field dependences of the magnetic moment show the effect to be of a collective nature.

Universal cryostat for applications, in solid state and cryogenic particledetector research, is designed as compact insert with 51 mm fitting diameter and providing temperatures down to 0.3 K. The key features of the cryostat are charcoal pumping of both 3 He and 4 He gases, which are permanently stored inside the cryostat under high pressure, complete electrical control during operation, and direct user application line, making the cryostat universal laboratory cryogenic equipment. This cryostat was developed after analysis of many modern research needs in easy to use and inexpensive cryogenic equipment and optimazed for application in laboratories without long experience in low temperature techiques.

The feasibility of thermoelectric detection in cryogenic detectors was demonstrate at elevated temperature of 1 K with a 33 mm3 volume silicon absorber placed in electrical field. Au:Fe-Nb thermocouple was used as a thermometer, installed directly on the heat absorber. The resolution, provided by Au:Fe-Nb thermocouple with SQUID read-out was 2.10−7 K/Hz1/2, which is one order of magnitude less than expected, and was limited by a noise of SQUID electronics.

A thermal detection of recoil electrons caused by (anti)neutrino scattering is considered in viewpoint of non-zero neutrino magnetic moment. A compact, low-background tritium-based antineutrino source providing a flux of 2.1015cm−2s−1 is proposed. An upper limit of 2.10−12 µB is expected for germanium 1L volume calorimetric detector.

An analysis of the relationship between the local crystal and electronic structure of the Ba1−x KxBiO3 and BaPb1−x BixO3 perovskite systems, which was made in terms of an empirical model based on EXAFS spectroscopy studies of the above compounds, led to the conclusion that superconductivity is possible in the Ba1−x LaxPbO3 system. The Ba1−x LaxPbO3 multiphase compound synthesized at a pressure of 6.7 GPa was found to contain a superconducting phase with a critical temperature T c ⋍11 K.

Research in cryogenic particle detection in Dubna is currently an experimental approach to the theoretically predicted energy resolution and threshold for massive calorimetric detectors through optimization of a thermometry, electronics and cryogenic arrangement. Particular attention is focused on silicon detectors utilising the ionization-into-heat conversion phenomenon in order to obtain an eV threshold per kg of mass. The first results for a silicon detector with 30 cm3 volume, operating at (10–70) mK temperatures and assisted with an InSb:Mn thermistor and a very low 1 f noise JFET preamplifier are presented.

The intermetallic compounds ${\mathrm{LaRu}}_{2}$ and ${\mathrm{CeRu}}_{2},$ as well as several quasibinary systems ${\mathrm{Ce}}_{1\ensuremath{-}x}{\mathrm{La}}_{x}{\mathrm{Ru}}_{2},$ were synthesized at a pressure of 8 GPa. The x-ray diffraction data showed the pure cubic $C15$ structure for all samples. The x-ray absorption measurements gave the value 3.23 for the Ce valence. Time-differential perturbed angular correlation measurements with the ${}^{111}\mathrm{In}$-doped samples have shown (i) ${}^{111}\mathrm{In}$ substituted for Ru; (ii) in ${\mathrm{LaRu}}_{2}$ a single value of the quadrupole frequency ${\ensuremath{\nu}}_{Q}=234$ MHz for the daughter ${}^{111}\mathrm{Cd}$ nuclei was observed; (iii) in ${\mathrm{CeRu}}_{2}$ two distinct equally populated sites for ${}^{111}\mathrm{Cd}$ were revealed with ${\ensuremath{\nu}}_{Q}=218$ and ${\ensuremath{\nu}}_{Q}=153 \mathrm{MHz}.$ The low-temperature magnetic measurements showed that magnetic moments about $0.3{\ensuremath{\mu}}_{B}$ per formula unit are inherent in all samples and indicated at a coexistence of superconductivity and magnetic ordering. In particular, the magnetic and superconducting correlations are developing, most probably, in the same system of ruthenium $4d$ electrons.

Radiation exposure using gamma sources with Co-60 was employed for the disinfection and disinfection of bedding from passenger cars. An effective scheme of exposure was developed and optimal dose determined: 10 kGy.

The derivation of the lower critical field H c1 through magnetization measurements for the samples yielding large demagnetization effect is discussed. SQUID magnetometry and circular thin film samples are taken in mind but results are applicable more widely. The conclusion is drawn out that only an upper limit for H c1 can be estimated thus eliminating the confidence of the published data obtained for thin films and platelike crystals.

Universal cryostat, designed as insertable unit with 51 mm fitting diameter and providing temperatures down to 0.3 K for applications in solid state and cryogenic particle detector research is described. The key features of the cryostat are charcoal pumping of both 3 He and 4 He gases, which are permanently stored inside the cryostat under high pressure, and complete electrical control during the operation.

It is known that if the continuous 2π-periodic function f(x) belongs to the class w(r) (r=1, 2, ...), i.e., it has an absolutely continuous derivative of order r—1 such that we have almost everywhere

Long-time heat release relaxation phenomena observed in different types of solids after cooling are attributed to the inelastic relaxation of thermoelastic stresses. Under this assumption an estimate of the relaxing power for polycrystalline copper is obtained that agrees with the observed values.

This paper describes a differential spectrophotometer for the study of solar energy conversion processes occurring in photosynthetic reaction centers in a temperature range of 1-300 K. Design, fabrication, and performance data are given in detail. The spectrophotometer incorporates a ruby laser for the excitation of stimulated Raman pulses in the near infrared range and is joined to a cryostat.

The spin correlation parameter Cnn has been measured in elastic pp scattering at 610 MeV at CM angles of 40, 67, 78, 90°. A polarized proton beam (PmaxB=0.38±0.02) and a ’’frozen’’ polarize proton target (PmaxT=0.97±0.04) have been used in the experiment.

The virgin magnetization of a type-II superconductor disk in a transverse field is discussed. The edge effects in a superconductor of rectangular cross section are considered, taking into account anisotropy and pinning. The penetration field of the geometrical barrier is calculated. It is shown that flux pinning at the edge corners influences the penetration field. The temperature dependence of the penetration field of platelike high-T{sub c} single crystals is discussed. {copyright} {ital 1997} {ital The American Physical Society}