Персона: Скобелев, Игорь Юрьевич
Загружается...
Email Address
Birth Date
Научные группы
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.
Статус
Фамилия
Скобелев
Имя
Игорь Юрьевич
Имя
9 results
Результаты поиска
Теперь показываю 1 - 9 из 9
- ПубликацияТолько метаданныеPossibility of estimating high-intensity-laser plasma parameters by modelling spectral line profiles in spatially and time-integrated X-ray emission(2019) Martynenko, A. S.; Skobelev, I. Yu.; Pikuz, S. A.; Скобелев, Игорь ЮрьевичWe address an issue of measuring the parameters of an envolving laser-produced plasma commonly observable in high-energy density physics experiments. Available diagnostic equipment does not provide enough temporal, and often spatial, resolution to distinguish the signal coming from the region and timeframe of outmost interest, where deposited energy density reaches its maximum. In this paper, we propose and describe an approach that makes it possible to estimate the plasma parameters existing at the time of the main laser pulse arrival, as well as on later stages of plasma expansion. It is based on the analysis of X-ray spectral line profiles in multicharged ion spectra registered in simple time and spatially integrated mode. As an example, specific calculations were made for Ly line of Al XIII and He line of Al XII and can be used to diagnose aluminum plasmas with an electron temperature of 400-1000eV, assuming that expanding plasma was homogeneous at every moment.
- ПубликацияТолько метаданныеEnhancement of K-shell spectroscopy for temperature measuring of isochorically heated matter in the sub-keV range(2023) Martynenko, A. S.; Pikuz, T. A.; Skobelev, I. Y.; Pikuz, S. A.; Скобелев, Игорь Юрьевич
- ПубликацияТолько метаданныеAbsolute keV x-ray yield and conversion efficiency in over dense Si sub-petawatt laser plasma(2022) Ryazantsev, S. N.; Martynenko, A. S.; Sedov, M. V.; Skobelev, I. Y.; Pikuz, S. A.; Скобелев, Игорь Юрьевич; Рязанцев, Сергей Николаевич; Седов, Максим ВладимировичLaser-produced plasmas are bright, short sources of X-rays often used for time-resolved imaging and spectroscopy. Absolute measurement requires accurate knowledge of laser-to-x-ray conversion efficiencies, spectrum, photon yield and angular distribution. Here we report on soft X-ray emission from a thin Si foil irradiated by a sub-PW picosecond laser pulse. These absolute measurements cover a continuous and broad spectral range that extends from 4.75 to 7.5 Angstroms (1.7-2.6 keV). The X-ray spectrum consists of spectral line transitions from highly charged ions and broadband emission with contributions from recombination, and free-free processes that occur as electrons decelerate in plasma electromagnetic fields. These quantitative measurements are compared to particle-in-cell simulations allowing us to distinguish bremsstrahlung and synchrotron contributions to the free-free emission. We found that experiment and simulation estimations of laser-to-bremsstrahlung conversion efficiency are in a good agreement. This agreement illustrates the accuracy of experiment and physical interpretation of the measurements.
- ПубликацияОткрытый доступPrecise 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.
- ПубликацияОткрытый доступOptimization 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.
- ПубликацияОткрытый доступAnalysis 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 ЮрьевичIn 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.
- ПубликацияОткрытый доступDetermining 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.
- ПубликацияТолько метаданныеEffect of plastic coating on the density of plasma formed in Si foil targets irradiated by ultra-high-contrast relativistic laser pulses(2020) Martynenko, A. S.; Pikuz, S. A.; Skobelev, I. Y.; Ryazantsev, S. N.; Скобелев, Игорь ЮрьевичThe formation of high energy density matter occurs in inertial confinement fusion, astrophysical, and geophysical systems. In this context, it is important to couple as much energy as possible into a target while maintaining high density. A recent experimental campaign, using buried layer (or "sandwich" type) targets and the ultrahigh laser contrast Vulcan petawatt laser facility, resulted in 500 Mbar pressures in solid density plasmas (which corresponds to about 4.6 x 10(7) J/cm(3) energy density). The densities and temperatures of the generated plasma were measured based on the analysis of x-ray spectral line profiles and relative intensities.
- ПубликацияТолько метаданныеX-ray spectroscopy validation of ionization potential depression models in dense plasma created by petawatt laser pulses(2020) Martynenko, A. S.; Pikuz, S. A.; Ryazantsev, S. N.; Skobelev, I. Y.; Скобелев, Игорь ЮрьевичDensity effects have great importance for studying the state of matter at high energy densities both for astrophysical and laboratory objects. At the moment, the question remains as to which model should be used for the description of the effect of ionization potential depression (IPD) in plasma with densities up to solid-state ones. Recent X-ray free-electron laser based researches claimed the adequacy of an early IPD model of Ecker and Kroll over the well-accepted model of Stewart and Pyatt, provided that these two models give significantly different predictions. Subsequent researches performed with optical lasers have received the opposite result. This work is intended to resolve the existing contradiction in conclusions of mentioned experiments. For the first time, the IPD effect for Si XIII ions of plasma generated by an ultrarelativistic optical laser pulse was described and quantified. We demonstrate the "disappearance" of electronic states up to the state with a principal quantum number of n = 4 (inclusively); the plasma density was varied from the critical to the near-solid one. A radiation-collision code PrismSPECT was used to distinguish different IPD models.