Персона: Писарев, Александр Александрович
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Институт лазерных и плазменных технологий
Стратегическая цель Института ЛаПлаз – стать ведущей научной школой и ядром развития инноваций по лазерным, плазменным, радиационным и ускорительным технологиям, с уникальными образовательными программами, востребованными на российском и мировом рынке образовательных услуг.
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Александр Александрович
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- ПубликацияОткрытый доступALUMINIUM OXIDATION IN PLASMA OF ABNORMAL GLOW DISCHARGE(НИЯУ МИФИ, 2023) Pisarev, A. A.; Tarasyuk, G. M.; Borisyuk, P. V.; Isaenkova, M. G.; Lebedinskii, Yu. Yu.; Zaripova, M. M.; Исаенкова, Маргарита Геннадьевна; Писарев, Александр Александрович; Тарасюк, Григорий Михайлович; Борисюк, Петр Викторович; Лебединский, Юрий ЮрьевичAluminum oxide layers in all its various forms have become widespread due to the unique combination of properties that can be modified by varying the conditions of their growth. The alumina layer can either be applied to the substrate by chemical and physical methods or grown by oxidation. For practical purposes, layers of various thicknesses and structures are needed. The standard method for obtaining thick (of the order of 100-1000 nm) porous layer is electric arc anodization in weak electrolytes. The standard method for obtaining thin (about 10 nm) layers is thermal oxidation. Dense layers of intermediate thickness are difficult to obtain by such methods. There are few papers in the literature that investigate the possibility of obtaining oxide layers with a thickness of tens of nanometers by oxidizing aluminum in oxygen plasma [1-5]. The description of the kinetics of the oxidation process in those works was given on the basis of the assumption of the diffusion character of oxygen transfer from the surface into the interior of the metal. This approach is absolutely unsuitable for description the transport of oxygen and aluminum through the oxide layer, since both oxygen and aluminum in the oxide are in the form of ions, and an electric charge is formed on the surface of the dielectric facing the plasma, so that the transport of oxygen coming from the plasma must occur under by the action of an electric field in the oxide dielectric layer. In this work, experiments on plasma enhanced oxidation (PEO) were carried out on the oxidation of aluminum in the anomalous glow discharge oxygen plasma, which provides uniform treatment over the entire surface of samples of arbitrary shape. Also, a simple model was proposed for description of the oxidation kinetics, taking into account oxygen transport in the electric field.
- ПубликацияОткрытый доступDeuterium trapping in co-deposited layers of ITER-relevant materials(НИЯУ МИФИ, 2021) Krat, S. A.; Prishvitsyn, A. S.; Vasina, Ya. A.; Fefelova, E. A.; Gasparyan, Yu. M.; Pisarev, A. A.; Писарев, Александр Александрович; Гаспарян, Юрий Микаэлович; Крат, Степан Андреевич; Пришвицын, Александр СергеевичHydrogen isotope accumulation in fusion devices is a serious problem. Because deuterium-tritium mixture will be a working gas in future fusion devices, including ITER tokamak, tritium accumulation is an issue from the perspective of radiation safety. In total, only 700 grams of tritium are allowed to be present in ITER vessel at any time, with additional 120 in the cryopumps, and 180 grams allocated to measurement error, to the total of 1000 grams.
- ПубликацияОткрытый доступHELIUM THERMAL DESORPTION FROM TUNGSTEN AFTER ION BEAM IRRADIATION AT ELEVATED TEMPERATURES(НИЯУ МИФИ, 2019) Ryabtsev, S. A.; Gasparyan, Yu. M.; Harutyunyan, Z. R.; Efimov, V. S.; Aksenova, A. S.; Pisarev, A. A.; Писарев, Александр Александрович; Ефимов, Виталий Сергеевич; Гаспарян, Юрий Микаэлович; Арутюнян, Зорий РобертовичHelium (He) is a product of deuterium-tritium reaction, so appearance of helium impurities will be unavoidable. In addition to He implantation from fusion plasma, He can be introduced into material by both neutron irradiation and tritium radioactive decay. Presence of He in plasma-facing materials may significantly influence their mechanical properties and surface morphology [1, 2], as well as hydrogen isotope recycling [3, 4]. Tungsten (W) will be used as a plasma-facing material in ITER divertor [5], and it is considered also for application in future fusion devices. Therefore, investigation of He interaction with W is of great interest.
- ПубликацияОткрытый доступHYDROGEN CO-DEPOSITION WITH METALS IN PLASMA DISCHARGE(НИЯУ МИФИ, 2017) Krat, S. A.; Gasparyan, Yu. M.; Vasina, Ya. A.; Pisarev, A. A.; Писарев, Александр Александрович; Крат, Степан Андреевич; Гаспарян, Юрий МикаэловичDeposition of a single element film is always accompanied by co-deposition of a certain amount of other elements. This can be done properly to improve properties of the coating or due to contamination by impurities. In the field of thermonuclear fusion research, where hydrogen isotopes are used as a fuel, co-deposition with sputtered material from the wall is one of major mechanisms of hydrogen isotopes accumulation in the installation. Since D-T fuel will be used in ITER and future fusion reactors, accumulation of radioactive tritium will limit the lifespan of the installations due to safety concerns. For example, tritium accumulation in ITER is limited by 1 kg. This is why carbon materials were not accepted for the use in ITER. Basing on experiments, it was predicted that the safety limit could be reached after 100 of shots with tritium. Recent experiments in JET [1] demonstrated in the case of “ITER-like” wall (first wall – Be, divertor area - tungsten) accumulation of deuterium fuel in the co-deposits was 20 times lower than in the full-carbon wall campaign. This is both due to smaller amount of co-deposits and smaller concentration of deuterium in them.
- ПубликацияОткрытый доступDEUTERIUM RE-EMISSION AND THERMAL DESORPTION FROM IRON AND EUROFER(НИЯУ МИФИ, 2017) Ryabtsev, S. A.; Gasparyan, Yu. M.; Ogorodnikova, O. V.; Harutyunyan, Z. R.; Pisarev, A. A.; Арутюнян, Зорий Робертович; Огородникова, Ольга Вячеславовна; Писарев, Александр Александрович; Гаспарян, Юрий МикаэловичReduced-activation ferritic-marthensitic (RAFM) steels, such as Eurofer, are considered as candidates for structural materials in fusion reactors due to the high thermal conductivity, the low thermal expansion coefficient and good resistance to radiation swelling. There are also some concepts of fusion reactors, where RAFM steels also considered as material for plasma-facing components. In this regard, the key aspects of hydrogen (H) isotopes interaction with RAFM steels, such as tritium (T) retention and migration in these materials are particularly important as a point of safety concern.
- ПубликацияТолько метаданныеThe dependence of lithium emissivity from temperature in vacuum ЗАВИСИМОСТЬ СТЕПЕНИ ЧЕРНОТЫ ЛИТИЯ ОТ ТЕМПЕРАТУРЫ В ВАКУУМЕ(2019) Prishvitsyn, A. S.; Krat, S.; Harina, A. P.; Pisarev, A. A.; Пришвицын, Александр Сергеевич; Крат, Степан Андреевич; Писарев, Александр Александрович© 2019 National Research Center Kurchatov Institute. All rights reserved.Correct interpretation of IR video observation data of the surfaces of plasma-facing elements in fusion devices requires detailed knowledge about the emissivity factor of these surfaces in different conditions. In this work, results of emissivity measurements for free metallic lithium surface and a lithium surface supported by the capillary-porous system (CPS) are measured as a function of temperature in the range from 400 to 800 K. Emissivity of solid lithium changed from ~0.04 at 400 K to ~0.09 at 453 K. During melting a sudden drop of emissivity down to ~0.04 was observed. Emissivity increased linearly from 0.04 to ~0.15 with temperature increasing from 455 to 800 K. For fully wetted CPS, emissivity was close to that of free lithium surface for temperature up to ~570 K, while at higher temperature it was lower, probably due to changes in microrelief at high temperatures.
- ПубликацияОткрытый доступInfluence of synthesis conditions on the crystal and local structures of WO3 powders(2019) Zubavichus, Y. V.; Svetogorov, R. D.; Shchetinin, I. V.; Zheleznyi, M. V.; Popov, V. V.; Menushenkov, A. P.; Pisarev, A. A.; Berdnikova, M. M.; Yaroslavtsev, A. A.; Gaynanov, B. R.; Попов, Виктор Владимирович; Менушенков, Алексей Павлович; Писарев, Александр Александрович; Бердникова, Мария Михайловна; Гайнанов, Булат Радикович© Published under licence by IOP Publishing Ltd.Influence of synthesis conditions on the crystal and local structures of WO3 powders prepared by thermal decomposition of ammonium paratungstate and precipitation of tungstates aqueous solutions in strong acid conditions has been investigated. Combination of X-ray powder diffraction, X-ray absorption fine structure spectroscopy, IR- and Raman-spectroscopy, and scanning electron microscopy was used. The calcination of all initial compounds at temperatures ≥ 500C led to formation of the monoclinic γ-WO3 single phase. It was concluded that the neutral octahedral complex [W=0(0H)4(H20)] can be a structural unit of the precursors prepared in acidic suspensions. The local structure of synthesized tungsten oxides consists of edge-shared and corner-shared distorted octahedral WO6 species linked together.
- ПубликацияОткрытый доступOptical radiation from plasma of abnormal glow discharge in various gas mixtures(2019) Muller, T.; Misozhnikov, L.; Stepanova, T. V.; Borisyuk, Y. V.; Mozgrin, D. V.; Nenashev, P. S.; Norakidze, V. S.; Oreshnikova, N. M.; Pisarev, A. A.; Степанова, Татьяна Владимировна; Писарев, Александр Александрович© Published under licence by IOP Publishing Ltd.Optical radiation from plasma of abnormal glow discharge in Ar+N2, He+ N2 and N2+H2 was investigated. Lines of N2 N2 +, N, N+, Ar+, Ar, He, Fe, H, H2 and OH were detected by optical spectrometry. Discharge current and intensities of spectral lines of N2, N2 +, N, and N+ versus the concentration of Ar, He, and H2 in the gas mixtures were measured at various compositions of the working gas.
- ПубликацияТолько метаданныеA setup for study of co-deposited films(2020) Krat, S. A.; Popkov, A. S.; Gasparyan, Y. M.; Vasina, Y. A.; Prishvitsyn, A. S.; Pisarev, A. A.; Крат, Степан Андреевич; Гаспарян, Юрий Микаэлович; Пришвицын, Александр Сергеевич; Писарев, Александр Александрович© 2020 IOP Publishing Ltd and Sissa Medialab.A setup for investigation of thermal desorption spectra of gases accumulated in thin films deposited by plasma sputtering of solid targets is described. Deposition and thermal desorption spectroscopy (TDS) are performed in two different vacuum chambers separated by a gate valve with the sample transferred between the chambers in-vacuo. The temperature of the substrate for deposited films can be varied in the range of 300-800 K; and the deposition rate is controlled by a quartz microbalance. Thermal desorption of co-deposited gases is analyzed by a quadrupole mass spectrometer. Sputtering rate and evaporation of the film during TDS are measured by quartz microbalances. Three experiments are described 1) trapping of deuterium by the growing chemically active Li film with subsequent decomposition and evaporation of the film, 2) temperature dependent deuterium trapping in the growing W film resulting in trapping with several binding energies, and 3) chemical interaction of D-Li layer with water vapor leading to isotopic H-D exchange and chemical transformation of the deposited film.
- ПубликацияОткрытый доступModel for hydrogen accumulation in co-deposited layers(2020) Krat, S. A.; Prishvitsyn, A. S.; Vasina, Y. A.; Gasparyan, Y. M.; Pisarev, A. A.; Крат, Степан Андреевич; Пришвицын, Александр Сергеевич; Гаспарян, Юрий Микаэлович; Писарев, Александр Александрович© 2020 The Author(s)An improved diffusion based model for prediction of the hydrogen content in co-deposited layers depending on the deposition conditions (the properties of the material which is co-deposited with hydrogen, rate of deposition, hydrogen flux and particle energy, substrate temperature) is presented. The model is validated using experimental data for W, Mo and Al, and is compared to empirical scaling equations currently in use. It is shown that a good agreement is observed in regards to hydrogen content vs substrate temperature experimental data, and no disagreement with scaling equations can be seen in regards to the role of hydrogen flux and the rate of deposition. It is shown that the influence of hydrogen particle energy on the hydrogen content requires further investigation. In addition to hydrogen, models for other mobile impurities both in co-deposited layers and in layers under steady-state net erosion conditions are given.