The results of silicon–carbon coatings deposition on an aluminum substrate, imitating a groove, by electron beam evaporation of silicon carbide are presented. The distribution of the thickness, composition, morphology, and hardness of the coating over the substrate sections was measured. An analytical model is proposed that makes it possible to calculate the deposition rate depending on the coordinate of the substrate site. The calculated and experimental results, presented in relative units, show a satisfactory agreement.
Hydrogen contained in the gas mixture of transversely excited atmospheric-pressure (TEA) CO2 lasers plays an attractive role in improving the discharge stability and output characteristics of glow discharge by suppressing arc discharge. During the excitation of TEA CO2 lasers, hydrogen effectively relaxes the CO2 (010) level, with the action of inhibiting the O2 production by dissociating CO2 molecules, thus reducing the “bottleneck” in the operation of laser systems. We propose a new method that takes into account the role of hydrogen in the whole process from pumping to output of TEA CO2 lasers. We numerically evaluate the transition from glow to arc discharge in the discharge gap of TEA CO2 lasers. The current and voltage (V–I) differential equations of the pumping circuit in TEA CO2 lasers using corona pre-ionization are solved to determine the O2 concentration produced by the change in electron density. Then, the six-temperature model is combined to simulate the dynamics of high-power TEA CO2 lasers considering the change in gas mixtures with hydrogen. The determined discharge voltage and gas mixture are essential for designing and operating TEA CO2 lasers for suitable applications.
NiO and Cu:NiO powder prepared by sol-gel method and solution treatment was spin-coated on CdTe layer to form Cu:NiO back contact of CdTe solar cell. The performances of the solar cell with CdS/CdTe/Cu:NiO structure were simulated and analyzed using AMPS software. Through the simulations, we investigated the effect of the back contact layer thickness and carrier concentration on the solar cell performances. The maximum efficiency of 19.26
First mirrors are critical components of optical diagnostic systems for measuring parameters of thermonuclear plasma in tokamaks. The condition and surface quality of first mirrors affect the accuracy of measured data, such as plasma density, temperature, magnetic field magnitude and others. This work investigates the mechanism leading to catastrophic surface destruction of molybdenum and tantalum mirrors used in POINT diagnostic system of EAST tokamak. The destruction of molybdenum and tantalum mirrors—which are transition metals, along with tungsten—is visually observable due to the high reflectivity of their surfaces, initially polished to achieve the required reflective properties. This makes first mirrors a convenient tool for studying surface destruction processes of all transition metals used as the first wall of tokamaks. Thus, in this work, first mirrors with polished surfaces are considered as elements of the first wall of fusion reactors, prepared for detailed study of erosion processes resulting from exposure to thermonuclear plasma. It is noted that it is precisely the mirror surface that allows visual observation of the catastrophic nature of the destruction of molybdenum and tantalum surfaces. Surface studies based on optical microscopy have revealed predominant destruction of surface structures along intergranular spaces and in regions of point defects arising from plasma exposure. X-ray photoelectron spectroscopy made it possible to establish the effect of the return to the first-wall surface of positively charged molybdenum ions and molybdenum-containing radicals. This work presents a destruction mechanism for transition metals that follows from the presented experimental facts. The study emphasizes that catastrophic plasma-chemical destruction occurs with all tokamak components made of transition metals that face the plasma.
The plant operation simulation system is a device that analyzes the operating dynamics of the plant and supports the operator to conduct operational training in the same environment as the actual situation of the plant. With the rapid development of computer science and technology, various types of plant operation simulation systems have been developed worldwide, used for control system design, operator training, and development of operating procedures, and recently, advanced scientific and technological achievements have been introduced to further improve the performance of process simulators and expand their application range. This paper presents a methodology for real-time modeling of the dynamics of a single-phase fluid flow network, which is a large part of the plant thermal system configuration, and, this basis, aims to perform operational simulations of auxiliary systems of the plant.
