Combined exposures of tungsten by stationary and transient hydrogen plasma heat loads: preliminary results

Influence of combined hydrogen plasma exposures on tungsten behavior was studied in QSPA Kh-50 facility and steady-state ion beam system FALCON. Pulsed plasma loads (0.45 MJ/m²) were below the tungsten melting threshold. The influence of addition steady-state heat flux (of 0.43 MW/m² during 900 s) on development of surface damage in tungsten targets was studied. Evolution of residual stresses and lattice spacing were investigated. For combined irradiation faster relaxation of residual stresses occurred. The damage of exposed surface was caused by physical spattering and cracks appearing.Влияние комбинированных водородных плазменных экспозиций на поведение вольфрама изучено в КСПУ Х-50 и ионно-лучевой системе FALCON. Импульсные нагрузки (0.45 MДж/м²) были ниже порога плавления вольфрама. Было изучено влияние дополнительных стационарных тепловых нагрузок (0,43 MВт/м² в течение 900 с) на развитие поверхностных повреждений в вольфрамовых образцах. Развитие остаточных напряжений и параметра решетки было изучено для различных видов плазменного облучения. При комбинированном облучении зарегистрирована быстрая релаксация остаточных напряжений. Повреждения облученных поверхностей обусловлены физическим распылением и появлением трещин.Вплив комбінованих водневих плазмових експозицій на поведінку вольфраму вивчено в КСПП Х-50 и іонно-променевій системі FALCON. Імпульсні навантаження (0.45 MДж/м²) були нижче порогу плавлення вольфраму. Було вивчено вплив додаткових стаціонарних теплових навантажень (0,43 MВт/м² протягом 900 с) на розвиток поверхневих пошкоджень у вольфрамових зразках. Розвиток залишкових напружень і параметра решітки було вивчено для різних видів плазмового опромінення. При комбінованому опроміненні зареєстровано швидку релаксацію залишкових напружень. Пошкодження опромінених поверхонь обумовлені фізичним розпорошенням і появою тріщин

Thermal expansion and Debye temperature of Ti-Zr-Ni quasi-crystal

Thermal expansion coefficient and Debye temperature of single-phase Ti₄₁.₅Zr₄₁.₅Ni₁₇ quasi-crystal have been determined from changes in the positions and intensities of X-ray deffraction lines within 80-300 K temperature range. The thermal expansion of the icosahedral crystal has been found to be isotropic. The average thermal expansion coefficient and Debye temperature have been determined to be alpha = 8*10⁻⁶ K⁻¹ and Od = 340 K

Modification of the Properties of Carbon Films for Photovoltaic Converters

The semiconductor materials with values of energy band gap in the range of 1-2 eV are the most suitable for manufacturing solar cells. These objects include some of the carbon allotropic modifications, as well as quantum dots on the surface of these materials, which use as the basis for the creation of new optoelectronic devices based on nanostructures. This paper presents the investigations of optical properties and structure of synthesized multilayer system diamond-like carbon film/ carbon quantum dots/C60film (DLC/Qdots/C60). When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3027

Condensation-dependent porosity in film nanostructures

The formation processes and behavior of submicro-, micro- and macropores in amorphous, poly- and single-crystalline condensed systems at multiple-factor external influence are considered. The pore formation mechanisms depending on physical and technological condensation conditions are discussed as well as effects of external factors on the porous structure stability.Рассмотрены процессы образования и поведения пор в аморфных, поли- и монокристаллических конденсированных системах при многофакторных внешних воздействиях. Обсуждаются механизмы порообразования в зависимости от физико-технологических условий конденсации и влияние внешних воздействий на стабильность пористых структур.Розглянуто процеси утворення i поведiнки субмiкро-, мiкро- i макропор у аморфних, полi- та монокристалiчних конденсованих системах при багатофакторному зовнiшньому впливi. Обговорюються механiзми пороутворення у залежностi вiд фiзико- технологiчних умов конденсацiї i вплив зовнiшнiх чинникiв на стабiльнiсть пористих структур

The methodology for X-ray diffraction investigation of icosahedral quasicrystals substructure

Method of quantitative estimates of the parameters of the icosahedral quasicrystals substructure, including specific phason defects, developed and successfully worked out using the experimental models of quasicrystalline Al₇₀Pd₂₁Re₉, Ti₄₁.₅Zr₄₁.₅Ni₁₇ and Al₆₄.₅Pd₂₁Mn₁₄.₅ with different preparation technology. The method is based on the analysis of the diffraction lines' width of complete X-ray diffraction pattern. The results are in a good agreement with the prehistory of the samples

Electrical resistivity of Ti₄₁.₅Zr₄₁.₅Ni₁₇ quasicrystals in the temperature region 0.3–300 K

The electrical resistivity of icosahedral quasicrystals Ti₄₁.₅Zr₄₁.₅Ni₁₇ was investigated in the temperature region between 0.3 and 300 K on samples of different quality. In the temperature region between 0.3 and 2 K, the influence of external magnetic fields up to 16 kOe on the superconducting transition of these materials was investigated. The temperature dependence of the resistivity in the region of the superconducting transition varies in a step-like manner. The data of the x-ray analysis imply the presence of several different quasicrystalline phases. Above the superconducting transition, a resistivity minimum is observed

Structure and substructure variations of icosahedral Ti₄₁.₅Zr₄₁.₅Ni₁₇ quasicrystals under irradiation imitating outer space factors

The article presents the results of studying the changes of coherent length, micro-strain value, density of phason defects and residual macro-stresses in Ti₄₁.₅Zr₄₁.₅Ni₁₇ icosahedral quasi-crystalline ribbons after irradiation by VUV (hν = 10.2 eV, duration up to 40 h), electron and proton fluxes (hν = 100 KeV with doses D up to 13·10¹⁶ cm⁻²), X-ray bremsstrallung (hν = 1 MeV with doses D up to 10000 rad). It is shown that the scale of the substructure changes, defect density, their type and parameters depend on the perfection degree of the original structure and impact energy power