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 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 доступInfluence of True Diffusion Coefficient on Hydrogen Diffusion in Tungsten in the Field of Defects(2019) Pisarev, A.; Giniyatullin, B.; Писарев, Александр Александрович© Published under licence by IOP Publishing Ltd.Numerical calculations of thermal desorption spectra, permeation, and accumulation of hydrogen in radiation damaged tungsten have been made using two approximations for the diffusion coefficient: The commonly used approximation of Fraunfelder and that of Heinola, which he proposed to describe only the most high temperature data of Fraunfelder.
- 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.
- ПубликацияОткрытый доступFormation of nanoscale structures in thin films deposited by reactive magnetron sputtering of binary metal targets in Ar+O2+N2 gas mixture(2019) Bernt, D.; Ponomarenko, V.; Leshchev, S.; Pisarev, A.; Лещев, Сергей Валерьевич; Писарев, Александр Александрович© Published under licence by IOP Publishing Ltd.Bi-metal targets of ZnSn and SiAl were sputtered in A+O2+N2 gas mixtures at various N2/O2 ratios, and the deposited films were investigated by AFM and XPS. No nitrogen was detected in the films even at the highest nitrogen partial pressure in the gas, and the films were oxides. The concentration of the doping metal component in the deposited film increases with the increase of nitrogen partial pressure in the working gas. These experimental observations were supported by numerical calculations of the sputter-deposition process using a SRIM/SIMTRA+RSD software. It was shown that added nitrogen promotes sputtering of doping metal components of the targets, and the concentration of oxygen remains high enough to substitute the less active nitrogen in the growing film. The films consisted of nanograins with the average diameter, which decreased from 18 nm to 3 nm with increase of nitrogen content in the working gas. This effect was explained by the mechanism of abnormal grain growth: the film consisted of grains of oxides of two metals with different concentrations. The doping metal forms very fine nanograins of oxides, which suppress the growth of oxides of the main metal. With increase of nitrogen in the working gas mixture, the sputtering rate of doping metals from the cathodes and their respective concentration in the growing films increases, so the average diameter of oxide grains forming the coating decreases.
- 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.
- ПубликацияОткрытый доступHYDROGEN AND HELIUM RETENTION IN TUNGSTEN UNDER ION IRRADIATION(НИЯУ МИФИ, 2017) Gasparyan, Yu.; Zibrov, M.; Efimov, V.; Ryabtsev, S.; Ogorodnikova, O.; Pisarev, A.; Писарев, Александр Александрович; Гаспарян, Юрий Микаэлович; Огородникова, Ольга ВячеславовнаInteraction of helium and hydrogen ions with tungsten is intensively investigated during last decades in relation to construction of fusion reactor. Tungsten has the high melting temperature and the energy threshold for sputtering and, therefore, is considered as plasma facing material (PFM) in fusion devices in the area of largest heat loads and small energies of ions (divertor area). In particular, tungsten will be used in the international experimental reactor ITER, which is now under construction.