Персона:
Писарев, Александр Александрович

Научные группы

Научная группа

Лаборатория «Прикладная ионная физика и масс-спектрометрия»

Организационные подразделения

Организационная единица

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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Писарев

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Александр Александрович

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Теперь показываю 1 - 10 из 26

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Influence 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.
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Optical 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.
Открытый доступ
INTERACTION 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 Андреевич
A 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.
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Model 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.
Только метаданные
A 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.
Только метаданные
Low-Temperature Plasma Nitriding of Low- and High-Chromium Steels
(2020) Borisyuk, Y. V.; Oreshnikova, N. M.; Pisarev, A. A.; Писарев, Александр Александрович
© 2020, Allerton Press, Inc.Abstract: The possibility of plasma nitriding without altering the surface morphology of structural steels 30Ni2CrMoV (30ХН2МФА) and 30CrMnSi (30ХГСА) with low chromium contents and steels 03Cr11Ni10Mo2Ti (03Х11Н10М2Т-ВД) and Cr12Mo (X12M) with high chromium contents is studied at temperatures of 400–450°C. Compound layers do not form in 30Ni2CrMoV and 30CrMnSi steels upon nitriding at low nitrogen concentrations in mixtures of N2+H2, and their surface morphologies remain the same. Nitriding can be done for steels 03Cr11Ni10Mo2Ti and Cr12Mo without forming compound layers, but the surface roughness increases at both low and high concentrations of nitrogen in the working gas.
Только метаданные
Retention of Deuterium in the Surface Layers of Tungsten Preliminarily Irradiated with Helium Ions
(2020) Harutyunyan, Z. R.; Gasparyan, Y. M.; Efimov, V. S.; Ryabtsev, S. A.; Pisarev, A. A.; Арутюнян, Зорий Робертович; Гаспарян, Юрий Микаэлович; Ефимов, Виталий Сергеевич; Писарев, Александр Александрович
© 2020, Allerton Press, Inc.Abstract: The retention of deuterium in tungsten preliminarily irradiated with helium ions is investigated by means of thermal desorption spectroscopy (TDS). Preliminary irradiation is performed with a He+ ion beam having an energy of 3 keV and fluence ranging in the interval 1019–1021 He m−2, in order to produce a defect structure typical of different degrees of damage. The specimens are then irradiated with D+3 ions having an energy of 2 keV and a weak fluence of 1019 D m−2, with subsequent TDS analysis to characterize the interaction between deuterium and helium-induced defects. It is shown that an increase in the deuterium retention is observed as soon as irradiation with the minimal fluence of helium ions, but it falls to the background level at fluences above 5 × 1021 He m−2.
Открытый доступ
PULSED ABNORMAL GLOW DISCHARGE WITH HOLLOW CATHODE FOR NITRIDING OF INTERNAL CYLINDRICAL SURFACES
(НИЯУ МИФИ, 2017) Borisyuk, Yu. V.; Kozlova, V. V.; Mozgrin, D. V.; Oreshnikova, N. M.; Stepanova, T. V.; Pisarev, A. A.; Писарев, Александр Александрович
Plasma nitriding is a method of thermochemical treatment, which is widely used to enhance surface hardness, fatigue strength, and corrosion resistance of steels [1,2]. In industry, glow discharge is commonly used for this purpose. A specific task of plasma technologies is treating of cavities, which are usually inaccessible for plasma. Still, the need to modify cavities and tubes of small diameters and large aspect ratios exists. Abnormal glow discharge with hollow cathode in the pulse-periodic mode was proposed for this purpose in [3]. This work is devoted to investigation of ignition and properties of the abnormal glow discharge in tubes and demonstration of nitriding of internal surfaces of the tubes.
Только метаданные
On the kinetic analysis of the hydrogen thermal desorption spectra for graphite and advanced carbon nanomaterials
(2020) Nechaev, Y. S.; Alexandrova, N. M.; Shurygina, N. A.; Cheretaeva, A. O.; Pisarev, A. A.; Писарев, Александр Александрович
© 2019, © 2019 Taylor & Francis Group, LLC.This study is devoted to a further development and application of our previous results, including the method of kinetic analysis of the hydrogen thermal desorption spectra (TDS) processes in materials heating with only one rate. As shown in this study, from such TDS data, the activation energies (Q) and the per-exponential factors (K0) of the rate constants (K) of the hydrogen desorption processes can be determined (evaluated with the enough accuracy) with the help of our method, including the standard deconvolution of TDS spectra by “pure” (that’s symmetrical) Gaussian curves (peaks), along with the identification (interpretation) of the peaks, and revealing their atomic mechanisms. Some critical aspects of using the pure Gaussian curves approach, and/or the first order reactions Kissinger approach (that’s is asymmetrical curves), especially for the diffusion controlling cases, along with approaches of Polanyi–Wigner equation of the first-order processes (that’s asymmetrical curves) and the second order processes (that’s symmetrical curves) are taken into account, as well. As an example, such a treatment and identification (interpretation) of TDS data on deuterium TDS spectra for graphite exposed to high flux plasma at high temperatures have been performed.
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Blocking of annihilation of Frenkel pairs by He atoms
(2020) Degtyarenko, N. N.; Pisarev, A. A.; Дегтяренко, Николай Николаевич; Писарев, Александр Александрович
© Published under licence by IOP Publishing Ltd.The results of DFT modelling of blocking the annihilation of Frenkel pairs at small distances between vacancy and self interstitial atom is performed in application to "subthreshold"radiation defects formation in W. It is shown that even at small distances sufficient for spontaneous annihilation of the Frenkel pair, He atoms can suppress the annihilation near the surface. In some cases an additional vacancy can appear close to the surface thus increasing the radiation damage. It is concluded that He impurities can be an additional reason for subthreshold"radiation damage.