Персона: Маренков, Евгений Дмитриевич
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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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Маренков
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Евгений Дмитриевич
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- ПубликацияОткрытый доступAssessment of laser induced breakdown spectroscopy accuracy for determination of hydrogen accumulation in tungsten(2021) Tsygvintsev, I. P.; Marenkov, E. D.; Gasparyan, Y. M.; Stepanenko, A. A.; Маренков, Евгений Дмитриевич; Гаспарян, Юрий Микаэлович; Степаненко, Александр Александрович© 2021 The Author(s)Laser-induced breakdown spectroscopy (LIBS) is an in situ method of determining hydrogen (H) content in plasma-facing materials in tokamak fusion reactors. Observing radiation from the plasma plume produced by a powerful laser pulse during the target exposition characterizes the sample composition. This is typically accomplished using the Saha-Boltzmann (SB) plot technique under local thermodynamic equilibrium (LTE) conditions. Despite many experimental studies dedicated to applying LIBS to determine H isotope retention in fusion reactor materials, the current understanding of this method's intrinsic accuracy remains inadequate. In this report, we use numerical calculations to estimate the relative error of determining H content in a sample using LIBS. As an example. we consider LIBS to study a W sample loaded with H in a vacuum. Under typical LIBS pulse parameters (109 W/cm2 and 12 ns duration), the error can be quite large, approximately 70%. We demonstrate that the error tends to decrease as the laser pulse intensity increases. Various factors contributing to the relative error are examined and their dependence on the LIBS plasma parameters is discussed. The SB plot remains a straight line even when LTE conditions are violated, making it difficult to anticipate the experimental results’ error.
- ПубликацияОткрытый доступVAPOUR SHIELDING OF SOLID TARGETS EXPOSED TO HIGH HEAT FLUX(НИЯУ МИФИ, 2015) Pshenov, A. A.; Eksaeva, A. A.; Krasheninnikov, S. I.; Marenkov, E. D.; Маренков, Евгений ДмитриевичThe thickness of a Tungsten monoblocks composing future ITER divertor is supposed to be 8 mm only. Severe erosion caused by a high heat fluxes during transients, such as Type I ELMs and disruptions, therefore is a limiting factor to PFCs lifespan. Thermal loads over the range of Q = 0.5−2 MJ/m2 on the timescale of τ = 0.3− 0.6 ms are expected during Type I ELMs. Even larger heat fluxes, of the order of = − Q 0.5 5 MJ/m2 are expected during thermal quench stage of disruption lasting approximately τ = 1 −3 ms [1]. Under the influence of the extreme heat fluxes serious surface modification and cracking of the Tungsten monoblocks is anticipated [2]. Moreover, melting of a thin surface layer is likely. Melt motion contributes seriously to the material erosion [3]. The other sources of erosion are melt splashing, in form of a droplet ejection, and stationary evaporation [4]. These mechanics lead to a cold dense secondary plasma region formation near the irradiated surface. Intense re-radiation of the incident plasma flow energy in the secondary plasma layer results in a significant reduction of the heat flux reaching the target surface [5]. Accounting for this vapour shielding effect is essential to estimate the surface erosion properly. Predicting the divertor plates lifespan therefore requires deep understanding of all the processes mentioned and their interplay.
- ПубликацияТолько метаданныеShielding of liquid metal targets in plasma of linear devices(2020) Marenkov, E. D.; Pshenov, A. A.; Kukushkin, A. S.; Маренков, Евгений Дмитриевич© 2020 Author(s).We apply a 0D model of shielding for simulations of liquid Li exposure experiments in He plasma of the Magnum-PSI linear device. The model accounts for all the most essential processes in the vapor cloud and plasma-surface interactions. The simulation results are in good agreement with the target surface temperature measurements. A factor of 10 increase in the erosion flux leads to a 100 °C decrease in the surface temperature, still giving a reasonable agreement with experiments. Therefore, the temperature measurements are inconclusive with respect to determining whether enhanced erosion takes place or not. We observe that only 10% of the eroded material is redeposited, while several other works suggest up to 99% redeposition. We show that low redeposition is a consequence of the low electron temperature, about 0.3 eV, in the vapor cloud and that the ratio of the ionization length to the transverse cloud size is the critical parameter to look at. Hence, the redeposition factor is not a universal quantity and can vary in quite a broad range depending on the plasma parameters and machine geometry.
- ПубликацияОткрытый доступERO-PSI CODE FOR NUMERICAL SIMULATION OF EXPERIMENTS ON TUNGSTEN SPUTTERING IN LINEAR PLASMA DEVICE PSI-2(НИЯУ МИФИ, 2015) Eksaeva, A. A.; Marenkov, E. D.; Borodin, D.; Kirshner, A.; Laenger, M.; Kurnaev, V. A.; Kreter, A.; Маренков, Евгений ДмитриевичPlasma-wall interaction is one of the recognized issues for thermonuclear reactor performance and seems to be a key direction in fusion researches in the framework of the ITER project [1]. Tungsten (W) has been chosen as a main material for construction of ITER divertor due to its low sputtering at edge plasma temperatures, large melting temperature, and small uptake of tritium.
- ПубликацияОткрытый доступAPPLICATION OF LIBS, LA-QMS, LA-TOF-MS FOR FUSION RELEVANT MATERIALS ANALYSIS(НИЯУ МИФИ, 2021) Efimov, N. E.; Sinelnikov, D. N.; Bulgadaryan, D. G.; Gasparyan, Y. M.; Vovchenko, E. D.; Marenkov, E. D.; Маренков, Евгений Дмитриевич; Ефимов, Никита Евгеньевич; Вовченко, Евгений Дмитриевич; Синельников, Дмитрий Николаевич; Гаспарян, Юрий МикаэловичOne of the critical issues on the way to controlled nuclear fusion is related to plasma wall interaction. Such interaction leads to co-deposition of hydrogen isotopes together with eroded first wall materials. It is known that the deuterium-tritium (DT) mixture will be used in ITER and future fusion devices as a fuel. So as the accumulation of radioactive tritium in the machines is limited by the nuclear license, there is a need for some remote fuel retention monitoring system. In current devices, the total fuel amount is determined from the gas balance (difference between input and output flows) measurements and from a post mortem analysis of plasmafacing components. One of the most promising techniques which can be applied in situ in tokamaks is based on laser irradiation of the surface of interest followed by mass- or optical spectroscopy. Such a technique was already applied in TEXTOR tokamak to the hydrogenic carbon layers [1], and it is included in the task list of ITER with a high priority.
- ПубликацияТолько метаданныеModeling the vapor shielding of a liquid lithium divertor target using SOLPS 4.3 code(2021) Marenkov, E. D.; Kukushkin, A. S.; Pshenov, A. A.; Маренков, Евгений ДмитриевичIn this letter, we report the very first results of SOLPS4.3 simulations of a liquid lithium (Li) divertor, including vapor shielding effects. A peculiarity of Li as a target coating material is the strong dependence of the erosion rate on the target temperature. We have implemented a new erosion model in SOLPS, taking this dependence into account. Simulations of the T15-MD tokamak divertor with Li-coated divertor targets have been performed. Li erosion is determined by physical sputtering, evaporation, and thermal sputtering. The results of the simulations show that a shielding effect occurs, providing a reduction of the target heat flux to values below 8 MW m(-2). At the same time, the upstream plasma dilution in the high-power regimes, where shielding is most efficient, is very strong, meaning that in practical terms, it may be difficult to rely on the shielding effect for heat flux control in the configuration considered.
- ПубликацияТолько метаданныеThe kinetic theory of prompt redeposition in the case of thin Debye sheath(2024) Marenkov, E. D.; Маренков, Евгений Дмитриевич
- ПубликацияТолько метаданныеSimulation of lithium flow, redeposition, and vapor shielding in liquid lithium divertor of T-15MD tokamak with SOLPS 4.3 code(2022) Marenkov, E. D.; Pshenov, A. A.; Kukushkin, A. S.; Маренков, Евгений Дмитриевич
- ПубликацияТолько метаданныеDiagnostics Complex of the First Wall and Divertor of Tokamak with Reactor Technologies: Control of Erosion and Temperature and Monitoring of Fusion Fuel Build-up(2022) Razdobarin, A. G.; Gasparyan, Yu. M.; Dmitriev, A. M.; Elets, D. I.; Bulgadaryan, D. G.; Krat, S. A.; Marenkov, E. D.; Гаспарян, Юрий Микаэлович; Елец, Денис Игоревич; Крат, Степан Андреевич; Маренков, Евгений Дмитриевич
- ПубликацияТолько метаданныеThe influence of the adiabatic index on the radiation dynamics of self-similar expanding laser-produced plasma plume(2022) Marenkov, E. D.; Sinelnikov, D. N.; Efimov, N. E.; Bulgadaryan, D. G.; Gasparyan, Y. M.; Маренков, Евгений Дмитриевич; Синельников, Дмитрий Николаевич; Ефимов, Никита Евгеньевич; Гаспарян, Юрий Микаэлович© 2022 Author(s).The radiation dynamics of an adiabatic self-similar expanding spherical plasma plume is considered. It is shown that the radiation intensities evolution strongly depends on the adiabatic index γ. For example, it is proven that the radiation intensity in a highly ionized plasma plume increases over time if γ= 5/3 and has a minimum in time if γ< 5/3. The analytical results are compared to measurements of the radiation from lithium laser-produced plasma. A lithium sample was irradiated by a powerful (42 J/cm2) laser pulse, and radiation of produced lithium plasma was registered by a monochromator. Reasonable agreement with the experiments is reached for γ= 5/4.