The paper deals with the optical radiation interaction with solids. It is shown that none of the existing ideas about the light reflection gives explanations to the known phenomena arising from the interaction between optical radiation and a solid. It is suggested that the optical radiation reflection is a collective process associated with the self-organization of electrons with a photon. This suggestion explains a number of physical phenomena that have not been explained before, for example, the Goos–Hänchen and Imbert–Fedorov beam shifts, which are natural processes in such representation of reflection.

The study was conducted at the cyclotron laboratory of the Tomsk Polytechnic University, on the use of a new form of target utilized in the production of fast-neutrons. The flux of fast-neutrons emitted by a novel target of beryllium powder compressed in a copper mold has been measured using Al and Fe foils as detectors. The change in the neutron flux in terms of the deuteron energy was studied by using thin aluminum filters. The increase of neutron flux reached about 60% when comparing with results obtained previously by our team when only the Be-target was used, this increase referred to the reaction Cu (n, 2n). In addition, comprehensive experimental graphs were obtained using our results beside other results from related literatures. It was found that they almost agree with the experimental results from the previous studies at energies less than 12 MeV, but then the neutron flux starts to increase when using a target of Be-powder compressed in a copper mold. The difference may become greater at energies above 15 MeV and the enhancement could be many times larger. Furthermore, fitted curves and their equations were obtained for the neutron flux as a function of deuteron-energy in the energy-range between 0.5 and 50 MeV. Also, the average energy of neutrons can be calculated from the derived equations for deuteron-ions in the energy-range from 2.6 to 40 MeV. The results of this study are new and promising, so that when confirming these results at higher energies above 15 MeV, we can obtain a greater neutron yield when using a target of Be-powder compressed in a copper mold or other metals with higher cross section of the reaction (n, 2n). The high intensity beams of fast-neutrons could be employed in many crucial applications, such as radiotherapy, production of radioactive isotopes, and more.

CrNx coatings were deposited at high rates (100-130 nm/min) using hot Cr target magnetron sputtering enhanced by a radio-frequency inductively coupled plasma (RF-ICP) source in an Ar + N-2 atmosphere. Besides separation of inert and reactive atmosphere, the RF-ICP source can be an effective tool for ion assistance in case of coating growth and to tailor film parameters. The effects of nitrogen flow rate and substrate bias potential on microstructure and functional properties of the CrNx coatings were investigated. An increase in nitrogen flow rate favored the formation of a looser microstructure of the coatings, while substrate biasing had the opposite effect. The functional properties were strongly dependent on the phase composition of the CrNx coatings. The change in coating microstructure significantly affected hardness, elastic modulus, adhesion, friction coefficients and corrosion resistance. The results indicated that ion assistance can be a key feature for regulating functional properties in the considered type of coating deposition. Cr2N and CrN compound coatings with high hardness (~20 GPa) and low corrosion current density (i(corr & nbsp;)~3-5.10(-9) A/cm(2)) in a 3.5 wt% NaCl solution were obtained by high-rate deposition.

The paper studies atoms evaporating from the 1370 aluminum alloy surface and the heat-affected zone during electron-beam welding. The proposed mathematical model is used to predict the spatial temperature distribution and mass losses of devices made of 1370 aluminum alloy depending on welding conditions. Experimental research concerns these processes. Theoretical calculations are compared with the experimental data. The alloy structure is investigated in the area of phase transformations. It is found that the vaporization intensity almost linearly depends on the beam current density and scanning speed. Experiments show that vaporization is an active process and can significantly affect the composition of the welding joint (mostly light elements evaporate) and, consequently, its mechanical properties.

In this paper, a simulations using MCNP code were carried out to determine the behavior and the response of a highly sensitive silver-activation detector which used for neutron detection. The detector consists of sandwiched alternating thin-sheets of silver and plastic scintillator EJ-299-15 instead of NE-110. The simulations also tacked into account two mono-energy neutrons 2.5 and 14 MeV to get the most efficient design of detecting and registering signals due to fast-neutrons interactions with the active materials (silver) and the plastic scintillator EJ-299-15. The energy and charge deposition of neutrons, photons and electrons at the detection-cell were simulated for different situations. The output simulations showed a valuable and promising ways to maximize optimization of designing and building such detectors suitable for a wide range of monitoring and detecting neutron sources.

A comprehensive study was conducted in the Cyclotron laboratory at National Research Tomsk Polytechnic University on the use of a new type of target utilized in the production of fast-neutrons. The flux and spectra of the fast-neutrons emitted by a novel target of compressed beryllium powder were studied. The neutron angular distribution was measured using Fe and Al foils as detectors in different angular situations of the target relative to the incident deuteron beam. It was found that there are some discrepancies in the neutron flux at 0 degrees degree for the detectors, up to about 20% for different target-beam angle. Likewise, the flux of neutrons in the energy range between 1 and 6 MeV make up about 83% of the total flux. Compering with previous works using solid target, we found an increase of nearly twice the yield of fast neutrons. And there is a probability that increase would rise steadily as the deuteron energies exceed 12 MeV as was the case in our work. The results of this study are new and promising and we can obtain a relatively greater neutron yield when using a compressed powder target. This is reflected positively on many applications that use fast-neutron beams, such as radiotherapy, radioactive isotopes, and even nuclear fusion experiments, among others.

Hot Cr target magnetron sputtering with radio-frequency inductively-coupled plasma (RF-ICP) source and separate gas (Ar+N2) inlets were used to obtain CrNx coatings. Higher deposition rates (137 nm/min) can be obtained using hot Cr target due to its sublimation at elevated temperatures in comparison with conventional reactive magnetron sputtering (10-50 nm/min). While the separated gas (Ar, N2) inlets and RF-ICP assistance were applied to improve stability and decrease hysteresis effects of deposition process. The corrosion behavior of the CrNx coatings was investigated by potentiodynamic method in a 3.5wt% NaCl solution in the range from -800 to 800 mV with a sweep rate of 0.5 mV/s. Results of the tests have shown the role of deposition parameters on corrosion resistance of the coatings. Pure chromium and CrN coatings had the lowest corrosion rate in 3.5wt% NaCl solution, when the substrate bias potential was equal to -100 V. Under these deposition conditions, the coatings had higher hardness (11.2 and 21.3 GPa for Cr and CrN) and denser columnar microstructure in comparison with the coatings obtained at lower bias potential. The reported study was funded by RFBR according to the research project № 20-38-90134.

This article describes hot Cr target magnetron sputtering enhanced by a radio-frequency inductively coupled plasma (RF-ICP) source in an Ar + N2 atmosphere. Optical emission spectroscopy revealed an opportunity to perform magnetron sputtering in an inert (Ar) atmosphere, while the CrNx coating can be deposited on a substrate in a chemically reactive atmosphere formed by the RF-ICP source. High stability and repeatability of deposition process were observed, and the deposition rate of the CrNx coatings increased from 106 to 127 nm/ min as N2 flow rate rose. The power of the RF-ICP source and the N2 flow rate can be used to tailor and control deposition conditions. The XRD and WDS measurements showed the effect of deposition conditions on the crystal structure and elemental composition of CrNx coatings. It was found that the change of substrate bias, RF-ICP source power and N2 flow rate result in variation of coating stoichiometry from pure Cr to CrN.

The aim of this work is to optimize and investigate the relationship between the collimation-filed size and their geometries and the fast-neutron intensity and their energy-spectrum. Advantageously for these purposes, a prototype of collimator was designed and constructed to simulate different geometrical and materials compositions. Beams of fast neutrons generated by the reaction Be-9(d, n) with 13.6 MeV deuteron energy were investigated. The average energy of the emitted neutrons is about 6-7 MeV. The maximum intensity was at neutron energy of 4-5 MeV. In the process of the study, experimental works were carried out with Al, Fe, Cu and Cd foils which positioned on the collimator aperture as neutron detectors. The neutron activation method and Gamma-spectrometer were deployed to determine the neutron intensities within the energy-range from thermal energies to 14 MeV. Experiments were conducted for ten different combinations of materials and geometries which can be adjusted by the removable-polyethylene collimator parts and the metal parts. It was concluded that the thermal and fast neutron flux were depended on the collimation-field size and materials, where the fast neutron flux output was about 100% more for bigger collimator 9x9 cm(2) comparing with the smaller ones 5x5 cm(2). And more than 60% in case of adding Lead layers into the collimator. These results could have influential implications on the fast neutron intensities and improvement of collimation systems for fast neutron therapy. Also, it could enhance the irradiation fluxes in the irradiation channels in nuclear reactors for medical isotopes productions and material testing and other applications.

The interatomic interaction in a metal in the presence of ionized states was investigated by means of pseudopotentials. The parameters of the form factors were determined by the quantum defect method using the spectroscopic terms of free ions. It is shown that ionization leads to a significant change in the interatomic interaction. Atoms land on the repulsive branch of the potential function, as a result of which the crystal lattice passes into a nonequilibrium state. The screening properties of conduction electrons strongly depend on their concentration, which can lead to a local change in the elastic properties of matter near the track of a fast charged particle.

The aim of this research was to investigate the relationship between the collimator aperture and fast-neutron flux, neutron-energy spectrum and absorbed dose rate. For remote therapy, rather large fluxes of fast neutrons are needed which can create dose levels in the tissues of at least 0.1 Gy/min with a source-patient distance of 1 m. Advantageously for these purposes, the 9Be(d, n) reaction was investigated with deuteron energy of 13.6 MeV. The mean energy of the outgoing neutrons was obtained using the code PACE 4 (LISE++) which gave the value of about 5.2 MeV. The maximum neutron flux was at an energy of about 2.5 MeV. Samples activation analysis was deployed to measure the neutron flux in the energy-region [0-14 MeV]. The experimental works were carried out using Al, Fe, Cu and Cd foils which installed on the collimator apertures. To investigate the neutron spectrum, fluxes, and dose rates absorbed at the position of patients, experiments were conducted for four different neutron irradiation-field sizes, which can be modified by the removable-polyethylene parts. Simulation results obtained by the code MCNP-4C and PACE4 (LISE++) were comparable with the experimental data to some extent with consideration of some uncertainties of PACE4 results. It can be concluded that the neutron flux is depended on the irradiation-field size where the neutron flux output for bigger aperture size was about +25% comparing with the smaller ones. These results could play a significant role in improving the neutron flux and optimizing the collimation system utilized in fast neutron therapy. In addition, this can lead to optimization of irradiation canals installed in the nuclear reactors which employed for production of medical isotopes, material testing and many other applications.

На основе метода псевдопотенциалов исследовалось межатомное взаимодействие в металле при наличии ионизированных состояний. Параметры формфакторов определялись методом квантовых дефектов по спектроскопическим термам свободных ионов. Показано, что ионизация приводит к существенному изменению межатомного взаимодействия. Атомы попадают на ветвь отталкивания потенциальной функции, в результате чего кристаллическая решетка переходит в неравновесное состояние. Экранирующие свойства электронов проводимости сильно зависят от их концентрации, что может приводить к локальному изменению упругих свойств вещества в области трека быстрой заряженной частицы. Рис. 4, табл. 1, список лит. 5 назв.

Hot Cr target magnetron sputtering with radio-frequency inductively-coupled plasma (RF-ICP) source and separate gas (Ar+N2) inlets were used to obtain CrNx coatings. Higher deposition rates (137 nm/min) can be obtained using hot Cr target due to its sublimation at elevated temperatures in comparison with conventional reactive magnetron sputtering (10-50 nm/min). While the separated gas (Ar, N2) inlets and RF-ICP assistance were applied to improve stability and decrease hysteresis effects of deposition process. The corrosion behavior of the CrNx coatings was investigated by potentiodynamic method in a 3.5wt% NaCl solution in the range from -800 to 800 mV with a sweep rate of 0.5 mV/s. Results of the tests have shown the role of deposition parameters on corrosion resistance of the coatings. Pure chromium and CrN coatings had the lowest corrosion rate in 3.5wt% NaCl solution, when the substrate bias potential was equal to -100 V. Under these deposition conditions, the coatings had higher hardness (11.2 and 21.3 GPa for Cr and CrN) and denser columnar microstructure in comparison with the coatings obtained at lower bias potential. The reported study was funded by RFBR according to the research project № 20-38-90134.

In this paper, simulations were carried out using Monte-Carlo N-Particle MCNP-4C code to determine the energy dependence of the response of a highly sensitive silver-activation detector used for fast-neutron detection after moderated to thermal neutrons. The detector consists of sandwiched alternating thin-sheets of silver and crystal scintillator Anthracene. The simulations also had considered different materials and designs to get the most efficient design for detecting signals from fast-neutrons interactions with the active materials (silver) and the scintillator. The energy and charge depositions of photons and electrons created by fast-neutron interactions with detector within the detection-cell were simulated for different scenarios. Owing on the simulations, a method to maximize the response by modifying the design was identified. The optimal configurations are suitable for a wide range of monitoring and detecting neutron sources especially for big detectors implemented for security purposes, where the costs and weighs can be reduced significantly.

Results of the development of protective chromium-containing coatings based on the FeCrNi and CrNi systems for fuel claddings within framework of the accident tolerant fuel (ATF) are presented in this paper. Coatings were deposited by the outer surface of cladding tubes fragments from E110 o.ch. alloy (sponge-based Zr-1%Nb) up to 500 mm length by complex ion-plasma treatment on ILUR-03 and KVK-10 installations. The results of the control tests carried out in high-temperature steam at the GAZPAR bench at 1200 °C up to 400 s showed that Cr-FeCrNi-Cr and Cr-CrNi-Cr coatings reduce total oxygen penetration into the alloy from 144 to 98 and 55 μm, respectively and Cr-CrNi-Cr coatings with a Mo barrier layer completely block the diffusion of oxygen into the material.

This paper reports on the effect of the type of Ni target (hot or cooled) on the angular thickness distribution, deposition rate and target utilization (K) for magnetron sputtering. Here it is shown that a change of magnetic field distribution does not influence on the mass of the deposited material. The Ni films will have a more uniform thickness, when films are obtained by hot target sputtering. The target utilization is higher for magnetron with hot target. This suggests a new approach to increase of K for the sputtering of magnetic targets.

Nickel-chromium coatings were deposited on Zr-1Nb alloy using magnetron sputtering systems with "hob" Ni and cooled Cr targets. The effect of coating composition on high-temperature oxidation resistance and hydrogen uptake of Zr-1Nb was studied. Hydrogen uptake of the alloy was measured in situ under gas-phase hydrogenation at 633 K. High-temperature oxidation was performed in air atmosphere at 1173-1373 K for 20 min. It was shown that the coating with high Ni content (83 at.%) drastically increases hydrogen uptake of the Zr-1Nb alloy and demonstrates low oxidation resistance even at 1173 K. The coatings with Cr content >= 45 at.% have low hydrogen permeability which reduces the rate of hydrogen uptake of the alloy. The oxidation resistance of the Ni-Cr coatings increases with Cr content in the as-deposited coatings. The pure Cr coating exhibits the best oxidation resistance: only 8 mu m-thick oxide layer was observed. There is also found the intensive diffusion of nickel into the alloy during high-temperature oxidation of the samples coated by Ni-Cr films with 55 and 17 at. % Ni. The as-deposited Ni-Cr coatings are less brittle than the pure Cr coating, but their mechanical properties degrade stronger than for the Cr coating after the oxidation test.

This study focuses on the deposition conditions, structural and mechanical properties of Cr films obtained by magnetron sputtering with hot target, and using high power pulsed supply with pre-ionization (pulse frequency 500 Hz, duty cycle 4% in the range of averaged power from 15 to 40 W/cm(2)). It has been found that hot target leads to a tenfold increase in the energy flux to the substrate compared to magnetron sputtering with cooled target. Intense sublimation from the target allows increasing the deposition rate of Cr films of about an order of magnitude. Moreover, the increase in the magnetron power may be accompanied by less heating of the substrates when depositing films of the same thickness. High power pulsed magnetron sputtering (HPPMS) with sublimating Cr hot target can be characterized by a combined mode in the film structure formation, leading to the formation of pores at the initial stage of growth. Cr films with a thickness of about 10 mu m, obtained using a hot target, have lower surface roughness, hardness, and Young's modulus compared with sputtered Cr from a cooled target.

The main focus of the article is the study of function mechanisms of a magnetron sputtering system (MSS) with a heat-insulated metal target in a self-sputtering gasless mode. A distinctive feature of the studied case is that the target evaporation takes place along with its sputtering. The research has been carried out on a copper target sample in molybdenum crucible. It has been found that because of evaporation the MSS can function stably using metal vapors without sputtering gas. The pressure in the chamber is 0.01 Pa. The current-voltage characteristics and spatial distribution of the copper atoms concentration near the target have been determined at the power density from 14 to 72W/cm(2). The minimum power density necessary for a stable gasless self-sputtering mode is 19.4 W/cm(2). Herewith the evaporated particles constitute approximately 87% of the total number of copper atoms near the target. It has been found that the erosion coefficients of metal targets at evaporation reach several tens of atoms per ion, which is an order of magnitude higher than the sputtering yield. Due to this, the coatings deposition under self-sputtering conditions takes place without reducing a deposition rate as compared to the case with sputtering gas. (C) 2018 Elsevier Ltd. All rights reserved.

This work is an investigation on the operation parameters for Ni films deposition by magnetron sputtering from target working at temperatures higher than the Curie temperature due to magnetic phase transition of the sputtered target, which is partial heat-insulated from the water-cooled magnetron body. The ferro- to paramagnetic transition of the target results in decrease of discharge voltage and rise of discharge current. Thereby, discharge power increases under voltage control mode or hot Ni target sputtering can occur at lower pressures under power control mode. Heating of the Ni target and its ferro- to paramagnetic transition leads to stabilization of the discharge parameters. The changes of the discharge current and power decreased from 10.5% to 2.5% during a single sputtering process under voltage control mode. Moreover, a slight increase of the deposition rates of 20…25% was determined, when hot target sputtering was performed. The XRD assessment showed that Ni films deposited by hot target sputtering have a textured crystal structure with larger grain sizes and lower residual stresses in comparison with cooled Ni target sputtering. When passing from cooled to hot target sputtering, the type of film growth changes from zone 1 to zone T, and surface roughness of Ni films decreased.