Персона:
Скобелев, Игорь Юрьевич

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.

Фамилия

Скобелев

Имя

Игорь Юрьевич

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Результаты поиска

Теперь показываю 1 - 10 из 11

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Clean source of soft X-ray radiation formed in supersonic Ar gas jets by high-contrast femtosecond laser pulses of relativistic intensity
(2020) Alkhimova, M.; Boldarev, A.; Feng, J.; Lu, X.; Ryazantsev, S.; Skobelev, I.; Pikuz, S.; Скобелев, Игорь Юрьевич
© 2020 The Author(s).In this work, we optimized a clean, versatile, compact source of soft X-ray radiation with an yield per shot up to in a plasma generated by the interaction of high-contrast femtosecond laser pulses of relativistic intensity with supersonic argon gas jets. Using high-resolution X-ray spectroscopy approaches, the dependence of main characteristics (temperature, density and ionization composition) and the emission efficiency of the X-ray source on laser pulse parameters and properties of the gas medium was studied. The optimal conditions, when the X-ray photon yield reached a maximum value, have been found when the argon plasma has an electron temperature of, an electron density of and an average charge of. In such a plasma, a coefficient of conversion to soft X-ray radiation with energies reaches, and no processes leading to the acceleration of electrons to MeV energies occur. It was found that the efficiency of the X-ray emission of this plasma source is mainly determined by the focusing geometry. We confirmed experimentally that the angular distribution of the X-ray radiation is isotropic, and its intensity linearly depends on the energy of the laser pulse, which was varied in the range of 50-280 mJ. We also found that the yield of X-ray photons can be notably increased by, for example, choosing the optimal laser pulse duration and the inlet pressure of the gas jet.
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Determining the short laser pulse contrast based on X-Ray emission spectroscopy
(2021) Martynenko, A. S.; Baird, C.; Booth, N.; Doehl, L.; Skobelev, I. Y.; Pikuz, S. A.; Ryazantsev, S. N.; Скобелев, Игорь Юрьевич
© 2021The interaction of high-power short lasers with solid density targets is an important application of modern solid state lasers. However, uncertainties in measurements due to lack of information on the laser pedestal-to-peak contrast limits the validity of many conclusions. We show that X-ray spectral measurements can provide a straightforward way for accessing the laser pedestal-to-peak contrast. The experiments use silicon targets and relativistic laser intensities of 3 × 1020 W/cm2 with a pulse duration of 1 ps. By not using or using a plasma mirror we compare low and high contrast measurements of the Ly-α line and its satellites to show that these lines are an effective laser contrast diagnostic. This diagnostic has potential to reduce uncertainty in future laser-solid interaction studies.
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The Role of Collision Ionization of K-Shell Ions in Nonequilibrium Plasmas Produced by the Action of Super Strong, Ultrashort PW-Class Laser Pulses on Micron-Scale Argon Clusters with Intensity up to 5 × 1021 W/cm2
(2023) Skobelev, I. Y.; Ryazantsev, S. N.; Kulikov, R. K.; Sedov, M. V.; Скобелев, Игорь Юрьевич; Куликов, Роман Константинович
The generation of highly charged ions in laser plasmas is usually associated with collisional ionization processes that occur in electronвЂ“ion collisions. An alternative ionization channel caused by tunnel ionization in an optical field is also capable of effectively producing highly charged ions with ionization potentials of several kiloelectronvolts when the laser intensity q andgt; 1020 W/cm2. It is challenging to clearly distinguish the impacts of the optical field and collisional ionizations on the evolution of the charge state of a nonequilibrium plasma produced by the interaction of high-intensity, ultrashort PW-class laser pulses with dense matter. In the present work, it is shown that the answer to this question can be obtained in some cases by observing the X-ray spectral lines caused by the transition of an electron into the K-shell of highly charged ions. The time-dependent calculations of plasma kinetics show that this is possible, for example, if sufficiently small clusters targets with low-density background gas are irradiated. In the case of Ar plasma, the limit of the cluster radius was estimated to be R0 = 0.1 Ојm. The calculation results for argon ions were compared with the results of the experiment at the J-KAREN-P laser facility at QST-KPSI.
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A Decade with VAMDC: Results and Ambitions
(2020) Albert, D.; Antony, B. K.; Ba, Y. A.; Babikov, Y. L.; Loboda, P. A.; Skobelev, I. Y.; Лобода, Петр Анатольевич; Скобелев, Игорь Юрьевич
This paper presents an overview of the current status of the Virtual Atomic and Molecular Data Centre (VAMDC) e-infrastructure, including the current status of the VAMDC-connected (or to be connected) databases, updates on the latest technological development within the infrastructure and a presentation of some application tools that make use of the VAMDC e-infrastructure. We analyse the past 10 years of VAMDC development and operation, and assess their impact both on the field of atomic and molecular (A&M) physics itself and on heterogeneous data management in international cooperation. The highly sophisticated VAMDC infrastructure and the related databases developed over this long term make them a perfect resource of sustainable data for future applications in many fields of research. However, we also discuss the current limitations that prevent VAMDC from becoming the main publishing platform and the main source of A&M data for user communities, and present possible solutions under investigation by the consortium. Several user application examples are presented, illustrating the benefits of VAMDC in current research applications, which often need the A&M data from more than one database. Finally, we present our vision for the future of VAMDC.
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Precise wavelength measurements of potassium He-and Li-like satellites emitted from the laser plasma of a mineral target
(2021) Filippov, E. D.; Martynenko, A. S.; Krus, M.; Renner, O.; Ryazantsev, S. N.; Skobelev, I. Y.; Mishchenko, M. D.; Pikuz, S. A.; Скобелев, Игорь Юрьевич
© 2020 Author(s).Atomic models of high-Z multicharged ions are extremely complex and require experimental validation. One way to do so is to crosscheck the predicted wavelengths of resonance transitions in He-and Li-like ions against precise spectroscopic measurements that use the spectral lines of H-like ions for spectra calibration; these reference data can be modeled with outstanding precision. However, for elements with Z of at least 15, it is quite difficult to create a hot dense plasma with a large concentration of H-like charge states. To mitigate this issue, the suggestion here is to use as laser targets particular minerals comprising elements with moderate (between 15 and 30) and low (less than 15) Z, with emission from the latter delivering perfect reference lines over a whole range of He-and Li-like moderate-Z emission under examination. This approach is implemented to measure the wavelengths of resonance transitions (1snp → 1s2 for n = 2, 3) in He-like K ions and their dielectronic satellites by irradiating plates of orthoclase (KAlSi3O8) with 0.5-kJ subnanosecond laser pulses. X-ray spectra of the laser-generated plasma contain the investigated lines of highly charged K ions together with precisely known reference lines of H-like Al and Si atoms. The K-shell spectral line wavelengths are measured with a precision of around 0.3 mÅ.
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Analysis of Ly(alpha) Dielectronic Satellites to Characterize Temporal Profile of Intense Femtosecond Laser Pulses
(2021) Ryazantsev, S. N.; Skobelev, I. Y.; Martynenko, A. S.; Alkhimova, M. A.; Mishchenko, M. D.; Pikuz, S. A.; Скобелев, Игорь Юрьевич
In the paper, an X-ray spectroscopy-based approach on laser pulse temporal profile characterization is described. The structure of dielectronic satellites to H-like Ly(alpha) lines strongly depends on a plasma electron density, so it can be applied for diagnostics. These spectral lines are mainly emitted during initial stage of laser plasma expansion. It means that plasma parameters obtained via them characterizes matter conditions in a region surrounding a spot of laser-matter interaction. In the case when a laser contrast is high enough, the radiation interacts with cold matter, which had not been preliminary perturbed by a laser prepulse, and the satellites structure shape corresponding to high densities should be observed. It allows us to consider the satellites as a diagnostic tool for the laser temporal profile quality. In the paper dependencies of the dielectronic satellites structure on electron densities obtained from detailed kinetic calculations in the wide range of plasma parameter for different elements are under discussion. Fundamental theoretical aspects of plasma diagnostic based on the feature of satellite structures shape in hot dense plasma, which led to development of the proposed method, are also explained.
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Optimization of a laser plasma-based x-ray source according to WDM absorption spectroscopy requirements
(2021) Martynenko, A. S.; Baird, C. D.; Booth, N.; Dohl, L. N. K.; Pikuz, S. A.; Skobelev, I. Yu.; Ryazantsev, S. N.; Скобелев, Игорь Юрьевич
© 2020 Author(s).X-ray absorption spectroscopy is a well-accepted diagnostic for experimental studies of warm dense matter. It requires a short-lived X-ray source of sufficiently high emissivity and without characteristic lines in the spectral range of interest. In the present work, we discuss how to choose an optimum material and thickness to get a bright source in the wavelength range 2 Å-6 Å (∼2 keV to 6 keV) by considering relatively low-Z elements. We demonstrate that the highest emissivity of solid aluminum and silicon foil targets irradiated with a 1-ps high-contrast sub-kJ laser pulse is achieved when the target thickness is close to 10 μm. An outer plastic layer can increase the emissivity even further.
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Investigation of plasma states formed under the interaction of high-power laser pulses with wire-shape Al-Cu target
(2021) Golovin, D. O.; Pikuz, T. A.; Abe, Y.; Honoki, Y.; Alkhimova, M. A.; Pikuz, S. A.; Skobelev, I. Y.; Скобелев, Игорь Юрьевич
© Published under licence by IOP Publishing Ltd.Study of warm dense matter remains a very important task for understanding of many unique phenomena observing as in astrophysical research as in inertial fusion and fast ignition. In this work, we studied the parameters of plasma created by 1.7 ps laser pulses of relativistic intensity of 7 × 1018 W/cm2 in a specially designed Al-Cu wire-shape target, in comparison with a flat Cu and Al foil targets. We observed the strong emission of neutral or virtually neutral Cu Ka line from both Cu foil and Cu wire part of targets, which indicates the creation of a dense state exposed to the intense flow of hot electrons. Parameters of the plasma were evaluated by comparison of experimental spectra with the results of modeling by collisional-radiative kinetic code PrismSpec under the plasma zone approach. The using of Al foil in front of Cu wire part of target allowed avoiding the direct heating of Cu-wire and acquiring spectra of Cu K-shell emission evidently belonging to emission of warm dense matter (WDM) state. The upper estimate for the electron temperature in WDM region was found to be below 80 eV.
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Laboratory disruption of scaled astrophysical outflows by a misaligned magnetic field
(2021) Revet, G.; Khiar, B.; Filippov, E.; Argiroffi, C.; Ryazantsev, S. N.; Skobelev, I. Y.; Pikuz, S.; Скобелев, Игорь Юрьевич
© 2021, The Author(s).The shaping of astrophysical outflows into bright, dense, and collimated jets due to magnetic pressure is here investigated using laboratory experiments. Here we look at the impact on jet collimation of a misalignment between the outflow, as it stems from the source, and the magnetic field. For small misalignments, a magnetic nozzle forms and redirects the outflow in a collimated jet. For growing misalignments, this nozzle becomes increasingly asymmetric, disrupting jet formation. Our results thus suggest outflow/magnetic field misalignment to be a plausible key process regulating jet collimation in a variety of objects from our Sun’s outflows to extragalatic jets. Furthermore, they provide a possible interpretation for the observed structuring of astrophysical jets. Jet modulation could be interpreted as the signature of changes over time in the outflow/ambient field angle, and the change in the direction of the jet could be the signature of changes in the direction of the ambient field.
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Enhanced X-ray emission arising from laser-plasma confinement by a strong transverse magnetic field
(2021) Filippov, E. D.; Makarov, S. S.; Burdonov, K. F.; Yao, W.; Skobelev, I. Y.; Pikuz, S. A.; Скобелев, Игорь Юрьевич
© 2021, The Author(s).We analyze, using experiments and 3D MHD numerical simulations, the dynamic and radiative properties of a plasma ablated by a laser (1 ns, 1012–1013 W/cm2) from a solid target as it expands into a homogeneous, strong magnetic field (up to 30 T) that is transverse to its main expansion axis. We find that as early as 2 ns after the start of the expansion, the plasma becomes constrained by the magnetic field. As the magnetic field strength is increased, more plasma is confined close to the target and is heated by magnetic compression. We also observe that after ∼ 8 ns, the plasma is being overall shaped in a slab, with the plasma being compressed perpendicularly to the magnetic field, and being extended along the magnetic field direction. This dense slab rapidly expands into vacuum; however, it contains only ∼ 2 % of the total plasma. As a result of the higher density and increased heating of the plasma confined against the laser-irradiated solid target, there is a net enhancement of the total X-ray emissivity induced by the magnetization.