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Information × Registration Number 0213U002983, 0108U000251 , R & D reports Title Investigation of the physical processes determined fundamental properties of the plasma-beam and gas discharge systems. popup.stage_title Head Goncharov A.А., Registration Date 20-02-2013 Organization Institute of physics NASU popup.description2 In result of accomplishing the project physical processes in a wide class of beam-plasma and gas discharge systems at low and atmospheric pressure are studied, and their mechanisms are determined. Model of kinetic processes in the plasma of low pressure discharge in I-He-Xe mixtures is developed. Dependencies of radiation intensities of atomic and molecular iodine on total pressure of the mixture in the discharge, and on partial pressure values of the mixture components are determined. Dependencies of spectrum shape, intensity and fluence of UV radiation from the plasma of hollow cathode discharge in oxygen, nitrogen and air with water vapor admixture on the discharge glow duration, working gas type, its pressure and specific power in the discharge are obtained. It is shown that inactivation efficiency of B.subtilis spores at their treatment by UV radiation of low pressure hollow cathode discharge in wavelength range of 200 ? 300 nm depends not only on the fluence value, but as well on the spectrum shape of UV radiation. It is determined that the most efficient UV radiation is quasi-continuous one in wavelength range of 200 ? 240 nm. It is found that the most efficient nitration of tool steel in the plasma of low pressure glow discharge in N2 Ar mixture occurs at argon content of about 25%. It is determined that this effect is due to fact that in this case atomic nitrogen concentration reaches its maximum value. It is determined that adding of small portion (1 6%) of SF6 to N2 results in essential change of the features of low pressure discharge plasma: 1) depletion of electron energy distribution function (EEDF) by electrons possessing energy of 0 0.1 eV at the expense of formation of SF6-, SF5-, SF4-, SF3-, F2-, F- ions, increase of relative quantity of electrons in the EEDF inverse region (2 6 eV) and growth of mean value of electron energy; 2) increase of plasma electric field strength and change of its spatial distribution; 3) excess of the density of negative ions over that of electrons by several times and change of spatial distribution of the plasma density. It is shown that electron energy distribution function (EEDF) of negative glow plasma in low pressure discharge on argon has two-temperature behavior, at that temperature of the major portion of electrons is about one order of magnitude less than that in the EEDF tail. It is determined that this effect is due to the process of excitation of Ar(2p10 - 2р1) electron levels from argon metastable states Ar(1s5) and Ar(1s3). Influence of water vapor admixture on the component content of species formed both in the plasma of filamentary barrier discharge on air, and in the remote chamber, is determined experimentally and theoretically. It is shown that increase of air humidity from 20 to 80% resuts in concentration growth of OH radicals in the discharge space by a factor of about 3. It is determined that the best match between the calculations and the experiment for both values of air relative humidity is observed at temperature value of 425K taken for the calculations, which is in a good agreement with experimentally measured rotational temperatures of nitrogen molecules and OH radicals. It is shown that the highest concentration in atmospheric pressure volume barrier discharge is exhibited by Ar2+, Ar2*(1 u+) and Ar*(1s5), at that Ar2+ concentration exceeds that of electrically neutral species by about two orders of magnitude. Dependencies of the value of Ar2+ ion flow from the discharge plasma on its power and argon flow rate are determined experimentally and theoretically. Peculiarities of free hydrogen formation in glow discharges of straight and tornado-shaped types in mixtures of ethanol an water vapors obtained from ethanol solutions with different concentrations and various rates of air blow-through are determined by means of numeric modeling. Electrolysis contribution in the process of molecular hydrogen formation is found for different parameters of the systems. Experimental device based on three-electrode flat capacitive RF (13,56 MHz) discharge in argon at atmospheric pressure is developed for plasma modification of surface features of materials, and preliminary researches of the device are performed. For the first time, principal possibility of obtaining two modes of liquid crystal alignment at treated polyimide surface - in parallel or perpendicular with respect to the treatment direction by means atmospheric pressure discharge is demonstrated. Several prototypes of ion sources for space charge cloud of plasma lens with separated zones of charge acquisition and electron trapping by magnetic fiend in a zone of the charge formation are developed and elaborated. These sources possess different configurations of cathodes and magnetic field in a volume of the charge acquisition, which provides an influence on conditions and efficiency of focusing of the beams of negative particles. For the time of project accomplishing, static characteristics of proposed prototypes of plasma lens with dynamic cloud of space charge formed by positive ions are determined. Particularly, the influence of dissipated magnetic field of the ion source on formation of the space charge cloud is shown. Efficiency of the lens electric field formation in dependence on residual gas pressure in the system, maximum potential of the source anode and magnetic field geometry is investigated. Possibility of radial electric field formation in the proposed lens with strength sufficient for focusing of the beams of negatively charged particles and free of significant spherical aberrations is shown. Physical, mathematical and numerical models of the processes in the proposed plasma lens volume are built taking into account magnetic field presence in the lens and energy variations of the ions formed in the discharge. The model takes into consideration permanent generation and loss of the cloud ions and propagation of the beam to be focused. Calculations performed by means of the proposed model enable deeper understanding of the processes in plasma-dynamic medium under study, and proceeding to optimization of the proposed device. Results of the modeling are in a good agreement with those obtained at the experimental setups. Parameters of negative ion source are optimized, which enables essential decrease of noise component of the current of obtained ion beam. It is shown that by means of forming dense accompanying plasma one can essentially reduce amplitude of unstable potential oscillations in the beam. Product Description popup.authors Баженов Володимир Юрійович Гончаров Олексій Антонович Горецький Віктор Петрович Губарєв Сергій Миколайович Добровольський Андрій Миколайович Дунець Сергій Петрович Калюжна Ганна Геннадіївна Літовко Ірина Валентинівна Мацевич Станіслав Володимирович Піун Віктор Михайлович Погуляй Сергій Сергійович Проценко Іван Макарович Рябцев Андрій Володимирович Стеценко Борис Володимирович Ткаченко Людмила Миколаївна Хомич Володимир Олексійович Ціолко В'ячеслав Володимирович Щедрін Анатолій Іванович Щуренко Анатолія Іванівна popup.nrat_date 2020-04-02 Close