Персона: Гаспарян, Юрий Микаэлович
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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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Руководитель научной группы "Плазменные и лазерные технологии новых материалов для ядерной и термоядерной энергетики"
Руководитель научной группы -Международный центр ядерных компетенций (МЦЯДКОМ)
Руководитель научной группы -Международный центр ядерных компетенций (МЦЯДКОМ)
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Юрий Микаэлович
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45 results
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- 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 доступPost-mortem analyses of gap facing surfaces of tungsten tiles of T-10 ring limiter(2021) Arkhipov, I.; Grashin, S.; Zibrov, M.; Pisarev, A.; Babich, Y.; Berdnikova, M.; Gasparyan, Y.; Gutorov, K.; Efimov, V.; Isaenkova, M.; Krat, S.; Krymskaya, O.; Kurnaev, V.; Stepanova, T.; Vovchenko, E.; Vizgalov, I.; Писарев, Александр Александрович; Бердникова, Мария Михайловна; Гаспарян, Юрий Микаэлович; Гуторов, Константин Михайлович; Ефимов, Виталий Сергеевич; Исаенкова, Маргарита Геннадьевна; Крат, Степан Андреевич; Крымская, Ольга Александровна; Степанова, Татьяна Владимировна; Вовченко, Евгений Дмитриевич© 2020 Elsevier B.V.Surfaces facing the gap between W tiles of the ring limiter of tokamak T-10 were analyzed after T-10 decommissioning using LIBS, SEM/EDA, XRD, TDS, and NRA techniques. Gaps with the width of 5 mm and 0.1 mm were nearly completely covered to their full depths of 22 and 15 mm, respectively, by a deposited film. The film was formed mainly by deposition of lithium that came from Li limiter and transformed in air to Li2CO3 and Li2O. Carbon was deposited from volatile hydrocarbons sputtered from the tokamak walls. Besides, carbon appeared due to chemical reaction with lithium in air. Chemical interactions of W with C, O, and Li led to formation W2C, WC, WO2, and Li2WO4. Carbides formed in W over the entire surface to the full depth of the gaps. Trapping of deuterium and helium in tiles was demonstrated. Possible influence of auto-oscillating discharges on ionization and ion trapping of C,D, and He in gaps is discussed.
- ПубликацияОткрытый доступAnalytical approach for description of deuterium content in deuterium-beryllium co-deposited layers(2021) De, Temmerman, G.; Krat, S.; Gasparyan, Y.; Vasina, Y.; Prishvitcyn, A. S.; Pisarev, A.; Крат, Степан Андреевич; Гаспарян, Юрий Микаэлович; Пришвицын, Александр Сергеевич; Писарев, Александр Александрович© 2021 The Author(s)Available literature data for beryllium content in D-Be co-deposited layers was modeled using newly developed model. It was shown that the model adequately describes the experimental results. An empirical scaling for the available trap concentrations as a function of deuteron energy was introduced in order to improve the agreement between the experimental data and model predictions. The limited recombination rate describes the co-deposition better than the unlimited one. Assuming two types of traps in the film with detrapping energies of 0.8–0.9 and 1.2–1.3 eV and trap concentrations of 10 at. % and 1 at. %, respectively, and the deuterium implantation energy of 15.6 eV, the average relative deviation between experimental and predicted D/Be values of 1.9 was observed, which is better than the empirical D/Be scalings.
- ПубликацияТолько метаданныеEFFECT OF PLASMA FACING MATERIAL SELECTION ON HYDROGEN ACCUMULATION IN FUSION DEVICES ВЛИЯНИЕ ВЫБОРА МАТЕРИАЛА ОБЛИЦОВКИ СТЕНОК ТЕРМОЯДЕРНЫХ УСТАНОВОК НА НАКОПЛЕНИЕ ИЗОТОПОВ ВОДОРОДА(2024) Gasparyan, Y. M.; Krat, S. A.; Гаспарян, Юрий Микаэлович; Крат, Степан Андреевич
- ПубликацияОткрытый доступCOMPARISON OF EROSION AND DEPOSITION IN JET DURING CARBON AND ITER-LIKE CAMPAIGNS(НИЯУ МИФИ, 2015) Krat, S.; Gasparyan, Yu.; Pisarev, A.; Mayer, M.; de Saint-Aubin, G.; Bykov, I.; Coad, P.; Likonen, J.; van Renterghem, W.; Ruset, C.; Widdowson, A.; JET-EFDA, contributors; Гаспарян, Юрий Микаэлович; Крат, Степан Андреевич; Писарев, Александр АлександровичErosion of plasma facing elements in fusion devices is an important question affecting their lifetimes. Redeposition of eroded materials may lead to accumulation of hydrogen isotopes, which makes it an important problem from the perspective of radiological safety. Redeposition in layers with carbon and beryllium could be a channel for hydrogen isotope accumulation.
- ПубликацияОткрытый доступINTERACTION OF LITHUM-DEUTERIUM FILMS WITH ATMOSPHERIC GASES(НИЯУ МИФИ, 2015) Popkov,A. S.; Krat, S. A.; Gasparyan, Yu. M.; Pisarev, A. A.; Гаспарян, Юрий Микаэлович; Писарев, Александр Александрович; Крат, Степан АндреевичA choice of plasma-facing materials is one of the key issues in thermonuclear fusion reactor design. Lithium as an element with the low atomic number is a promising material for plasma-facing components (PFC) in fusion installations and a number of experiments at tokamaks already demonstrated many positive effects on plasma operation [1,2]. Lithium can be used for conditioning, PFC on the base of of capillary porous system with liquid lithium are also considered. In any way, one can expect lithium co-deposition with hydrogen isotopes at the surface of PFC and at remote areas. Lithium as a good getter can accumulate high amount of hydrogen isotopes (deuterium, tritium) that can be a problem from the safety reason. Deuterium retention and thermal desorption from lithium films formed in plasma discharge were investigated in this work.
- ПубликацияТолько метаданныеLaser-aided diagnostic of hydrogen isotope retention on the walls of the Globus-M2 tokamak(2021) Mukhin, E.; Razdobarin, A.; Minaev, V.; Novokhatsky, A.; Gasparyan, Y.; Bulgadaryan, D.; Efimov, N.; Efimov, V.; Krat, S.; Popova, M.; Sinelnikov, D.; Vovchenko, E.; Dmitriev, A.; Elets, D.; Гаспарян, Юрий Микаэлович; Ефимов, Никита Евгеньевич; Ефимов, Виталий Сергеевич; Крат, Степан Андреевич; Синельников, Дмитрий Николаевич; Вовченко, Евгений Дмитриевич; Елец, Денис Игоревич© 2021The application of the laser-aided diagnostic using the nanosecond laser for direct measurement of hydrogen concentration on the walls of the Globus-M2 tokamak is under discussion. The D release after the laser irradiation with the fluence in the range of 0.1 - 4 J/cm2 was measured in laboratory experiments at the Large MEPhI mass-monochromator facility for W-D, Ti-D films, and for the W tile exposed in the Globus-M tokamak. The desorption flux was high enough to be detected during similar measurements inside the Globus-M2 tokamak. TMAP 7 modeling of D release from W-D films was done for the relatively low laser fluence (< 1 J/cm2). A reasonable agreement with experimental data has been achieved, and the depth of analysis was estimated.
- ПубликацияОткрытый доступИЗОТОПНЫЙ ЭФФЕКТ В НАКОПЛЕНИИ ВОДОРОДА В ОСАЖДЁННЫХ ИЗ ПЛАЗМЫ ВОЛЬФРАМОВЫХ СЛОЯХ(НИЯУ МИФИ, 2024) КРАТ, С. А.; ПРИШВИЦЫН, А. С.; ГАСПАРЯН, Ю. М.; ПИСАРЕВ, А. А.; Писарев, Александр Александрович; Пришвицын, Александр Сергеевич; Крат, Степан Андреевич; Гаспарян, Юрий МикаэловичВажность изучения накопления водорода в соосаждённых из плазмы металлических слоях во многом обусловлена опасностью избыточного накопления радиоактивного изотопа трития в термоядерных установках, где со-осаждение материалов стенки с частицами работчего газа – один из основных каналов накопления водорода в установке. Так как эксперименты с использованием трития крайне затруднены технически, опасны и дороги, подавляющее большинство работ в данной области проводится с использованием дейтерия как симулятора трития. При этом предполагается, что накопление трития будет происходить идентично накоплению дейтерия. В связи со сложностью проведения экспериментов с тритием, возможно провести опыты по сравнению свойств протия и дейтерия и сделать некоторые оценки в части трития на основе полученных данных.
- ПубликацияОткрытый доступComparison of erosion and deposition in JET divertor during the first three ITER-like wall campaigns(2020) Krat, S.; Mayer, M.; Baron-Wiechec, A.; Brezinsek, S.; Gasparyan, Y.; Крат, Степан Андреевич; Гаспарян, Юрий МикаэловичThe manuscript presents an overview of the erosion and deposition data in the inner and outer JET divertor observed during the first three ITER-like wall campaigns (JET-ILW1, JET-ILW2, JET-ILW3). Erosion and deposition were studied using core samples cut out from divertor tiles. For the studied samples a similar general deposition pattern was observed in all three campaigns: More than 60% of the total deposition occurred in the upper region of the inner divertor on tiles 0 and 1, where Be was transported and deposited from the scrape-off layer. High erosion was observed only on tile 5. In JET-ILW2 and 3, erosion together with high power fluxes was observed in the outer divertor at the bottom of tile 7. Additionally, deposition peaks were observed on the sloping parts of tiles 4 and 6, which were more pronounced in JET-ILW2 and 3 due to placing the strike point more often on these tiles. The deposits consisted primarily of Be, with some additional D and C. Deposition rates were observed to decrease from campaign to campaign, with the C deposition rate decreasing the most, more than 2 times from JET-ILW1 to JET-ILW3. D retention up to levels of similar to 1 at% was observed up to large depths in the W protective coatings in all campaigns.
- 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.