Персона: Синельников, Дмитрий Николаевич
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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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Дмитрий Николаевич
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- ПубликацияТолько метаданныеOverheating of Nanostructured Tendril Bundles due to Thermo-Field Emission(2020) Hwangbo, D.; Kajita, S.; Ohno, N.; Sinelnikov, D.; Bulgadaryan, D.; Efimov, N.; Kulagin, V.; Kurnaev, V.; Синельников, Дмитрий Николаевич; Ефимов, Никита Евгеньевич; Кулагин, Владимир Владимирович© 2021 IEEEField emission current accompanied by visualization of emission sites distribution was measured for nanostructured tendril bundles (NTB) on a tungsten surface. These structures are formed in linear simulators of plasma-surface interaction under helium plasma irradiation with Ne or N2 mixture, and unipolar arcing is often observed for such surfaces. It was shown that field emission current from NTB could be stable for a long period under constant electric field making these structures promising to use as flat cold cathodes. A numerical model was developed for calculating the thermo-field emission current and for checking the possibility of self-heating of the structures depending on their shape. Critical electric field values that lead to self-heating were estimated for different NTB shapes and compared with experimental results.
- ПубликацияОткрытый доступTungsten nano-fuzz surface degradation under ion beam(НИЯУ МИФИ, 2015) Sinelnikov, D.; Kurnaev, V.; Kolodko, D.; Solovev, N.; Колодко, Добрыня Вячеславич; Синельников, Дмитрий НиколаевичTungsten is the main candidate for plasma facing material in the divertor zone of a thermonuclear reactor due to high melting temperature, high thermal conductivity and low sputtering erosion yield. However, its surface can be modified by "fuzz" nanostructure, which can form in linear simulators and tokamaks [1] under helium irradiation fluence as high as ~1025m-2and sample temperature in the range of 1000-2000 K. Such structure significantly changes the plasma-wall interaction balance, which results in higher probability of unipolar arc ignition. In the case of arcing, erosion yield sharply increases, especially if arcing takes place on a fuzzy surface [2]. Tungsten fuzz is also characterized by high pre-breakdown current intensity, which could indicate the initial stage of unipolar arc ignition [3]. Prebreakdown currents are usually initiated by field emission due to amplification of electric field on sharp cathode relief. So, an investigation of emission properties dependence on surface relief during fuzz formation and destruction seems to be important for the prediction of unipolar arcing.
- ПубликацияОткрытый доступАнализ влияния режимов лазерного облучения поверхности при диагностике накопления изотопов водорода(2024) Ефимов, Н. Е.; Синельников, Д. Н.; Гришаев, М. В.; Гаспарян, Ю. М.; Ефимов, В. С.; Крат, С. А.; Гаспарян, Юрий Микаэлович; Ефимов, Никита Евгеньевич; Гришаев, Максим Валерьевич; Синельников, Дмитрий НиколаевичВ работе проведено сравнение сигналов лазерно-ассистированной масс-спектрометрии для двух длительностей лазерных импульсов (15 нс и 80 пс) на примере дейтерированных вольфрамовых пленок и образцов титан−ванадиевого сплава. Представлена методика подготовки насыщенных дейтерием образцов, обеспечивающая хорошо повторяющийся во времени выход дейтерия при нескольких последовательных выстрелах лазером, что может быть использовано для юстировки диагностической системы. Получена экспериментальная зависимость интегрального выхода дейтерия из исследуемых материалов от плотности энергии в импульсе. Продемонстрирована высокая чувствительность методики, а также слабая зависимость от длительности импульса лазерного излучения. Отмечено значительное изменение концентрации дейтерия в приповерхностном слое вольфрамовой пленки в ходе контакта с атмосферой.
- ПубликацияОткрытый доступSURFACE HYDROGEN ISOTOPES DETECTION BY LOW ANGLE ION SCATTERING SPECTROSCOPY(НИЯУ МИФИ, 2023) Sinelnikov, D. N.; Gasparyan, Y. M.; Grishaev, M. V.; Efimov, N. E.; Krat, S. A.; Nikitin, I. A.; Крат, Степан Андреевич; Гаспарян, Юрий Микаэлович; Синельников, Дмитрий Николаевич; Никитин, Иван Андреевич; Ефимов, Никита Евгеньевич; Гришаев, Максим ВалерьевичHydrogen isotopes retention in thermonuclear fusion reactors is limited due to safety regulations and should be well controlled. Surface conditions can strongly affect accumulation rates of hydrogen isotopes in the bulk of plasma facing materials. Therefore, in vacuo methods of surface composition control may help to investigate mechanisms of this effects.
- ПубликацияОткрытый доступESTIMATES OF He+ SCATTERED FROM THE SURFACE SURVIVAL PROBABILITY USING BINARY COLLISIONS CODES(НИЯУ МИФИ, 2019) Mamedo, N. V.; Kurnaev, V. A.; Sinelnikov, D. N.; Mamedov, I. M.; Синельников, Дмитрий Николаевич; Мамедов, Никита ВадимовичLow-energy (1-20 keV) ion scattering spectroscopy is the widespread method of surface analysis [1,2]. The surface layer composition can be reconstructed from narrow peaks in the energy spectra of the scattered inert gas ions and recoil ions [3]. The main advantage of the surface analysis using inert gas ions is the high sensitivity to the first layer of surface atoms. This is due to the low initial energy of the ions (and therefore small ion penetration depth) and the high neutralization probability of the reflected ions, which increases with the penetration depth of the incident particle into the solid [3]. However, for quantitative surface analysis, it is extremely important to determine the neutralization probability (or the probability of ion survival), since this method usually detects reflected ions only.
- ПубликацияОткрытый доступTIME-OF-FLIGHT ANALYSIS OF IONS FROM LASER-INDUCED PLASMA(НИЯУ МИФИ, 2023) Grishaev, M. V.; Efimov, N. E.; Sinelnikov, D. N.; Nikitin, I. A.; Gasparyan, Y. M.; Vovchenko, E. D.; Вовченко, Евгений Дмитриевич; Синельников, Дмитрий Николаевич; Ефимов, Никита Евгеньевич; Гришаев, Максим Валерьевич; Гаспарян, Юрий Микаэлович; Никитин, Иван АндреевичOne of the most detrimental phenomena in fusion research is the interaction of plasma with a surface of a first wall and in-chamber elements. It causes erosion of the plasma-facing components (PFC), which in turn results in a degradation of plasma parameters due to transport of erosion products into the hot plasma. On the other hand, these processes cause re-deposition of the eroded material together with fuel components (deuterium and tritium). This is the dominant mechanism for fuel retention in PFC.
- 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.
- ПубликацияОткрытый доступAPPLICATION OF KEV-ENERGY PROTON SCATTERING FOR SURFACE ANALYSIS(НИЯУ МИФИ, 2019) Bulgadaryan, D.; Sinelnikov, D.; Kurnaev, V.; Efimov, N.; Ефимов, Никита Евгеньевич; Синельников, Дмитрий НиколаевичLow- and medium-energy ion scattering (LEIS/MEIS) are widely used techniques of surface analysis [1–4]. Conventional LEIS/MEIS setups utilize noble gas ions and electrostatic energy analyzers that makes these methods very sensitive to composition of the uppermost atomic layers of an analyzed sample. However, high neutralization probability of noble gas ions restricts LEIS/MEIS depth profiling capabilities [5]. The use of hydrogen ions with lower neutralization probability instead of noble gas provides possibility to measure the thickness of surface layer if its atomic mass is very different from that of underlying target, that is the case e.g. in nanoelectronics [6] or for redeposition of plasma-facing materials in fusion devices [7]. In this work we present simulated and experimental data on implementation of keV-energy proton scattering (KEPS) for surface analysis.
- ПубликацияОткрытый доступQUANTITATIVE ANALYSIS OF THE TEMPERATURE DRIVEN CHROMIUM SEGREGATION IN W-Cr-Y ALLOY BY LOW ENERGY ION SCATTERING SPECTROSCOPY(НИЯУ МИФИ, 2023) Efimov, N. E.; Sinelnikov, D. N.; Wang, Y.; Harutyunyan, Z. R.; Gasparyan, Y. M.; Grishaev, M. V.; Nikitin, I. A.; Tan, X.; Синельников, Дмитрий Николаевич; Ефимов, Никита Евгеньевич; Арутюнян, Зорий Робертович; Никитин, Иван Андреевич; Гаспарян, Юрий Микаэлович; Гришаев, Максим ВалерьевичOne of the challenging problems which arise in the controlled nuclear fusion is related to the design and material choice of plasma facing components for the future reactors. Tungsten is considered to be one of the most suitable candidates due to its high melting point, thermal conductivity and relatively low erosion rate, and, therefore, it is planned to be used in nextgen facilities like ITER and DEMO. However, under high neutron fluxes its stable isotopes may form radioactive ones. Being not so hazardous while it is inside the reactor, in case of a loss of coolant accident (LOCA) a volatile oxide of W and of its transmutation products may appear, which is undesirable. A possible solution to avoid the release of the radioactive oxides is the use of self-passivating W-Cr-Y alloys [1], which under LOCA scenarios forms on the surface a chromium oxide, preventing the formation of tungsten oxide. Such alloys are of the great interest now, especially when it comes to analyzing the dynamics of the chromium release to the outermost layers [2,3]. In this work, capabilities of low energy ion scattering spectroscopy (LEIS) with small angle scattering to the characterization the surface morphology of W-11,4Cr-0,6Y after pre-annealing at different temperatures are revealed.
- ПубликацияОткрытый доступОТРАЖЕНИЕ ПРОТОНОВ ОТ СЛОИСТО НЕОДНОРОДНЫХ ТВЕРДЫХ ТЕЛ(НИЯУ МИФИ, 2023) Лобанова, Л. Г.; Афанасьев, В. П.; Гришаев, М. В.; Ефимов, Н. Е.; Никитин, И. А.; Синельников, Д. Н.; Синельников, Дмитрий Николаевич; Никитин, Иван Андреевич; Ефимов, Никита Евгеньевич; Гришаев, Максим ВалерьевичCalculation method of reflected from layered inhomogeneous solids light ions density fluxes is constructed. The method is based on analytically calculated and experimentally received reflection functions from homogeneous solids. Transmission function is calculated in Fokker-Plank approximation. Analytical results are verified on a base on comparison with experimental results.