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 Александрович

Проведено 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.

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.

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 Андреевич

The 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.

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.

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 Сергеевич

Hydrogen 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.