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The results of Monte Carlo simulation and test reflectometry experiments on the “Gorizont” neutron reflectometer (on the IN-06 pulsed neutron source at INR RAS) after its upgrade with a two-dimensional detector with a positioning system are presented. The two-dimensional detector makes it possible to use the instrument not only for neutron reflectometry, but also for small angle neutron scattering. Estimates of the instrument resolution and the spectra of the neutron beam at different collimations have been obtained using Monte Carlo simulation. Test reflectometry experiments have been performed on mirrors with known characteristics. The characteristics match the manufacturer’s data with an error of 5%, obtained from the simulation.

A complex radiation diagnostics facility “DRAGON” has been constructed at the reactor IR-8. The facility includes 3 beams for measurements using neutron and gamma radiation. The parameters of the facility are presented; the main units of the facility are described. The results of radiographic and tomographic experiments on the setup are presented.

A high-resolution neutron diffractometer has been fabricated on the basis of an IN-06 pulsed neutron source at the Institute for Nuclear Research, Russian Academy of Sciences. The diffractometer incorporates two blocks of detectors with helium neutron counters and time-of-flight (TOF) focusing at scattering angles of 156°–165°. A block of new-type high-efficiency scintillation detectors of thermal neutrons based on a ZnS(Ag)/LiF scintillator and silicon photomultipliers with TOF focusing is developed and tested. Test measurements are performed, and the diffractometer resolution is estimated. The diffraction pattern of nonmagnetic NiCrAl alloy is measured and used to determine the phase composition by means of the Rietveld method. It is demonstrated that the given setup can be applied to phase analysis.

A ring neutron detector has been developed for a time-of-flight diffractometer based on linear scintillation detectors. Light is transported over an organic glass light guide with a diffuse reflector. This scheme makes it possible to collect more photons than are collected in detectors based on wavelength-shifting fibers and to use avalanche photodiodes (SiPMs) instead of photomultiplier tubes. Testing confirmed that these detectors could be used as an alternative for widely used proportional neutron counters filled with 3He.

An important thermoelectric characteristic-the power factor of composite thermoelectric materials—is calculated on the basis of performed measurements of the thermopower, electric conductivity, thermal conductivity, and reference data. The investigated composites consist of intermediate-valence CeNi and YbAl3 intermetallic systems and elementary metals, nickel and chromium. On account of the specific transport properties of a heterogeneous medium, it becomes possible to increase the value of the power factor in composites at a sufficiently low concentrations of rare-earth-element-based intermetallic compounds. The dependences of the composite-thermoelectric-material power factor on the temperature and the mass fraction of valence-instable components are obtained.

Existing models of composite thermoelectric materials are analyzed. The power factor for several possible microstructures of composites that incorporate intermediate-valence intermetallides, silicides, and pure metals is calculated. It is shown that the largest power factor is achieved in the planar geometry (with alternating thermoelectric and pure metal layers). It is found that calculations according to the effective-medium theory are noticeably easier than those specified by methods based on calculating the effective kinetic coefficients. The maximum-possible power-factor values and optimal-mass fractions of good thermo-electric materials in composite systems are estimated.

A high-efficiency thermal-neutron detector based on ZnS(Ag)/LiF scintillator is described, which employs a new technique of signal pick-up with the aid of a light guide and avalanche photodiodes instead of optical fibers and photomultipliers. Results of tests on the RADEX pulsed neutron source are presented, in which neutron diffraction patterns of test objects have been obtained.

A study has been made of the effect of superheating of the melt on the position of the “solidification plateau” of tin. It is shown that crystallization occurs in a stepwise manner. An explanation is proposed in terms of coordinated atomic spheres, by the presence of short- and long-range bonds and their anisotropy.

(1989). An electron beam gun with a metallic rod cathode for welding heat exchanger equipment. Welding International: Vol. 3, No. 1, pp. 9-11.