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 доступСравнение удержания дейтерия в вольфрамовых пленках различной толщины(2024) Крат, С. А.; Пришвицын, А. С.; Сорокин, И. А.; Фефелова, Е. А.; Гаспарян, Ю. М.; Писарев, А. А.; Писарев, Александр Александрович; Гаспарян, Юрий Микаэлович; Пришвицын, Александр Сергеевич; Крат, Степан Андреевич; Сорокин, Иван АлександровичПроведено сравнительное исследование содержание дейтерия в со-осажденных из плазмы магнетронного разряда на молибденовые подложки вольфрам-дейтериевых слоях толщиной 50, 250 и 750 нм. Измерения проводились методом in vacuo термодесорбционной спектроскопии без контакта с атмосферой. Проведено моделирование экспериментальных данных в коде ТМАР7, получены концентрации и энергии ловушек, при которых достигается наилучшее согласие с экспериментом. Содержание дейтерия в пленках, осажденных при температуре ~100°С, составило 3–5 ат. %. Показано, что толщина пленок не оказывает существенного влияния на характеристики центров захвата удержания дейтерия, хотя вид спектров для наиболее толстых пленок несколько отличается.
- ПубликацияОткрытый доступВЛИЯНИЕ УЛЬТРАФИОЛЕТОВОГО ИЗЛУЧЕНИЯ НА СОДЕРЖАНИЕ И ДЕСОРБЦИЮ ДЕЙТЕРИЯ ИЗ СООСАЖДЕННЫХ ЛИТИЕВЫХ СЛОЕВ(НИЯУ МИФИ, 2021) Хомяков, А. К.; Крат, С. А.; Пришвицын, А. С.; Фефёлова, Е. А.; Гаспарян, Ю. М.; Писарев, А. А.; Писарев, Александр Александрович; Пришвицын, Александр Сергеевич; Гаспарян, Юрий Микаэлович; Крат, Степан АндреевичThe influence of ultraviolet irradiation of co-deposited lithium layers on the content and desorption of deuterium from them is considered. It was found that exposure to ultraviolet radiation suppresses desorption at high temperatures, facilitates desorption at low temperatures. Effects are considered that can form the basis for the development of methods for determining the places of accumulation of lithium hydride in tokamaks with lithium walls, as well as facilitating the removal of heavy hydrogen isotopes from the walls of installations.
- 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 доступCOMPARISON OF DEUTERIUM RETENTION IN TUNGSTEN AND WCrY ALLOY IN THE PRESENCE OF HELIUM(НИЯУ МИФИ, 2021) Harutyunyan, Z.; Gasparyan, Yu.; Pisarev, A.; Litnovsky, A.; Klein, F.; Linsmeier, Ch.; Писарев, Александр Александрович; Гаспарян, Юрий Микаэлович; Арутюнян, Зорий РобертовичDuring operation of the future fusion power plant, the plasma-facing components (PFC) will be exposed to intense fluxes of particles of deuterium, tritium, helium, as well as neutrons arising in the process of the D–T fusion reaction. In this regard, one of the important challenges is to minimize the accumulation of radioactive tritium in the PFC [1, 2], as well as to study the effect on the accumulation of helium impurities in the plasma.
- 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 метаданныеHelium retention in tungsten irradiated with He+ ion beam at elevated temperatures(2019) Kanashenko, S.; Ivanov, Y.; Ryabtsev, S.; Gasparyan, Y.; Efimov, V.; Harutyunyan, Z.; Aksenova, A.; Poskakalov, A.; Pisarev, A.; Гаспарян, Юрий Микаэлович; Ефимов, Виталий Сергеевич; Арутюнян, Зорий Робертович; Аксенова, Александра Сергеевна; Писарев, Александр Александрович© 2019Helium (He) retention in re-crystallized tungsten (W) irradiated with He+ ions at elevated temperatures (700–1200 K) and fluences in the range of 1020–1022 He/m2 was investigated by means of thermal desorption spectroscopy (TDS). Corresponding surface modifications were analyzed by scanning electron microscopy. Blisters were observed after irradiation at 700 and 1000 K, while the increase of the irradiation temperature up to 1200 K led to development of a complex sponge-like structure on the W surface. Significant surface transformations correlated with appearance of low temperature peaks in TDS spectra below the irradiation temperature. Possible mechanisms and explanations are discussed.
- ПубликацияОткрытый доступElastic backscattering as a method for the measurement of the integral lithium content in thin films on fusion-relevant substrates(2019) Mayer, M.; Krat, S.; Vasina, Y.; Prishvitsyn, A.; Gasparyan, Y.; Pisarev, A.; Крат, Степан Андреевич; Пришвицын, Александр Сергеевич; Гаспарян, Юрий Микаэлович; Писарев, Александр Александрович© 2019 Elsevier B.V.Different ion beam analysis techniques for the study of thin lithium-containing layers on top of fusion relevant materials are discussed and compared to each other. Elastic backscattering analysis (EBS) with protons is determined to be one of the most promising techniques and allows measurements of Li layers with thicknesses from ∼100 nm up to ∼600 μm, as shown by SIMNRA simulations. The best sensitivity for thin films (∼100 nm) can be achieved using 4 MeV protons with 170° scattering detection angle for layers on Mo and W substrates, and 2 MeV for C substrates. Experimentally EBS measurements were successfully tested for Li films with thicknesses from ∼50 nm up to ∼400 nm after air exposure. The Li films become strongly inhomogeneous and require averaging over multiple measurements in nearby areas. This necessitates averaging over multiple nearby measurement points, and limits the overall precision of the measurement.
- ПубликацияТолько метаданныеTemperature dependence of hydrogen co-deposition with metals(2019) Gasparyan, Y.; Krat, S.; Davletiyarova, A.; Vasina, Y.; Pisarev, A.; Гаспарян, Юрий Микаэлович; Крат, Степан Андреевич; Писарев, Александр Александрович© 2019 Elsevier B.V. The deuterium retention in aluminum and molybdenum films co-deposited in magnetron discharge has been measured in a wide range of substrate temperatures (from RT to 800 K) by means of thermal desorption spectroscopy. A multi-step temperature dependence was observed, which was compared with the diffusion based model and previous experimental data for tungsten films. The key role of lattice defects in deuterium trapping was demonstrated. The highest D retention among the investigated materials was observed in W films, which have the lowest H solubility, but the highest binding energies of hydrogen with defects. The detrapping energies and concentrations of defects in the films were estimated on the base of the model, and the energies are consistent with the data for bulk materials.