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1.
A. I. Magunov A. Ya. Faenov I. Yu. Skobelev T. A. Pikuz E. Biémont P. Quinet F. Blasco C. Bonte F. Dorchies T. Caillaud F. Salin C. Stenz 《Journal of Experimental and Theoretical Physics》2002,95(6):998-1005
The satellite structure of 1s2p 1,3 P 1-1s 21 S 0 lines of the He-like argon ion in plasma produced by a 45-fs laser pulse in a gas-jet cluster target is measured with a high spectral resolution. Radiation transitions 2p → 1s from autoionizing states (AISs) are detected for ions ranging from Li-like to F-like. The spectrum observed is theoretically simulated with the use of the spectroscopic data for the AISs of multicharged ions obtained within the multiconfiguration relativistic Hartree-Fock method. Good agreement with experimental data is obtained when the main population channels of these states are taken into account for typical values of cluster-target plasma parameters. 相似文献
2.
Calegari F Valentini G Vozzi C Benedetti E Cabanillas-Gonzalez J Faenov A Gasilov S Pikuz T Poletto L Sansone G Villoresi P Nisoli M De Silvestri S Stagira S 《Optics letters》2007,32(17):2593-2595
Elemental sensitivity in soft x-ray imaging of thin foils with known thickness is observed using an ultrafast laser-plasma source and a LiF crystal as detector. Measurements are well reproduced by a simple theoretical model. This technique can be exploited for high spatial resolution, wide field of view imaging in the soft x-ray region, and it is suitable for the characterization of thin objects with thicknesses ranging from hundreds down to tens of nanometers. 相似文献
3.
4.
N. A. Inogamov A. Ya. Faenov V. V. Zhakhovskii I. Yu. Skobelev V. A. Khokhlov Y. Kato M. Tanaka T. A. Pikuz M. Kishimoto M. Ishino M. Nishikino Y. Fukuda S. V. Bulanov T. Kawachi Yu. V. Petrov S. I. Anisimov V. E. Fortov 《等离子体物理论文集》2011,51(4):361-366
Laser‐matter interaction is defined by an electronic band structure of condensed matter and frequency ωL of electromagnetic radiation. In the range of moderate fluences, the energy absorbed by electrons from radiation finally thermalizes in the ion thermal energy. The thermalization processes are different for optical as compared with X‐ray quanta and for metals relative to semiconductors and dielectrics, since the light absorption and electron‐electron, electron‐ion dynamics are sensitive to the electron population in a conduction band and the width of a forbidden gap. Although the thermalization processes are different, the final state is simply a heated matter. Laser heating creates powerful stresses in a target if duration of a laser pulse τL is short in acoustic time scale. Nucleation and material removal take place under such stresses. Such way of removal is called here the spallative ablation. Thus the spallative ablation is an ablation mechanism universally important for qualitatively different materials and quanta (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
5.
Zhidkov AG Sasaki A Tajima T Auguste T D'Olivera P Hulin S Monot P Faenov AY Pikuz TA Skobelev IY 《Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics》1999,60(3):3273-3278
We have observed evidence of the emission of energetic He-and H-like ions of fluorine more than 1 MeV produced via the optical field ionization (OFI) from a solid target irradiated by an intense I=(2-4)x10(18) W/cm(2) (60 fs, lambda=800 nm), obliquely incident p-polarized pulse laser. The measured blue wing of He(alpha), He(beta), and Ly(alpha) lines of fluorine shows a feature of the Doppler-shifted spectrum due to the self-similar ion expansion dominated by superthermal electrons with the temperature T(h) approximately 100 keV. Using a collisional particle-in-cell simulation, which incorporates the nonlocal-thermodynamic-equilibrium ionization including OFI, we have obtained the plasma temperature, line shape, and maximal energy of accelerated ions, which agree well with those determined from the experimental spectra. The red wing of ion spectra gives the temperature of bulk plasma electrons. 相似文献
6.
V. P. Efremov S. A. PikuzJr. A. Ya. Faenov O. Rosmej I. Yu. Skobelev A. V. Shutov D. H. H. Hoffmann V. E. Fortov 《JETP Letters》2005,81(8):378-382
X-ray spectroscopic data are reported on the state of a silicon aerogel medium (SiO2) irradiated by a Ni ion flux with an energy of 4.7 MeV/nucleon. Radiation from the electron transitions to the K shell in multicharged Si ions is detected with spatial resolution along the direction of the beam propagation in the medium. Calculations performed for the ionization state and population of the levels excited in the silicon atoms of the target provide the estimate Te = 70–120 eV for the medium electron temperature in the ion tack region. Two-dimensional hydrodynamic calculations provide the estimate Te = 60–116 eV for the same conditions and densities of 0.5–2.5 g/cm3 of the excited target medium. 相似文献
7.
V. S. Belyaev V. I. Vinogradov A. S. Kurilov A. P. Matafonov V. S. Lisitsa V. P. Gavrilenko A. Ya. Faenov T. A. Pikuz I. Yu. Skobelev A. I. Magunov S. A. Pikuz Jr. 《JETP Letters》2003,78(11):703-706
The X-ray lines of ions in a solid target interacting with picosecond laser pulses of moderate intensity (2×1017 W/cm2) were measured on the “Neodim” laser facility. X-ray Ly α emission spectra of hydrogen-like fluorine ions were observed. Satellite lines were also observed, evidencing the presence of intense plasma oscillations. The positions and separation between the satellites allow their assignment to the intense electrostatic oscillations with an amplitude larger than 108 V/cm and a frequency of about 7× 1014 s?1 that is noticeably lower than the laser frequency ωlas~1.8×1015 s?1. It is suggested that these oscillations may be due to strong plasma turbulence caused by the development of plasma oscillations of the Bernstein-mode type under the action of a strong magnetic field generated in plasma. The experimental results are compared with the calculated spectra of multicharged ions. 相似文献
8.
I. Yu. Skobelev A. Ya. Faenov A. I. Magunov T. A. Pikuz A. S. Boldarev V. A. Gasilov J. Abdallach Jr. G. C. Junkel-Vives T. Auguste P. d’ Oliveira S. Hulin P. Monot F. Blasco F. Dorchies T. Caillaud C. Bonte C. Stenz F. Salin B. Yu. Sharkov 《Journal of Experimental and Theoretical Physics》2002,94(1):73-83
The heating of clusters by femtosecond laser pulses is studied theoretically and experimentally. Both the formation of a cluster target and the results of experimental studies of the cluster plasma by the methods of X-ray emission spectroscopy are considered. A numerical model of cluster formation in a supersonic gas jet is proposed. It is shown that detailed studies of two-phase gas-dynamic processes in a nozzle forming the jet give the spatial distributions of all parameters required for the correct calculation of the cluster heating by short laser pulses. Calculations of nozzles of different configurations show that in a number of cases an almost homogeneous cluster target can be formed, whereas in other cases the distributions of parameters prove to be not only inhomogeneous but also even nonmonotonic. A simple physical model of the plasma production by a femtosecond laser pulse and a picosecond prepulse is proposed. It is shown that a comparison of X-ray spectra with detailed calculations of the ion kinetics makes it possible to determine the main parameters of the plasma being produced. 相似文献
9.
Masahiko Ishino Anatoly Y. Faenov Momoko Tanaka Satoshi Tamotsu Noboru Hasegawa Masaharu Nishikino Tatiana A. Pikuz Takeshi Kaihori Tetsuya Kawachi 《Applied Physics A: Materials Science & Processing》2013,110(1):179-188
To study the interactions between picosecond soft x-ray laser (SXRL) beams and material surfaces, gold (Au), copper (Cu), and silicon (Si) surfaces were irradiated with SXRL pulses having a wavelength of 13.9 nm and a duration of ~7 ps. Following irradiation, the surfaces of the substrates were observed using a scanning electron microscope and an atomic force microscope. With single pulse irradiation, ripple-like structures were formed on the Au and Cu surfaces. These structures were different from previously investigated conical structures formed on an Al surface. In addition, it was confirmed that the development of modified structures, i.e., growth of hillocks on the Au and Cu surfaces, was observed after multiple SXRL pulse exposures. However, on the Si surface, deep holes that seemed to be melted structures induced by the accumulation of multiple pulses of irradiations were found. Therefore, it was concluded that SXRL beam irradiation of various material surfaces causes different types of surface modifications, and the changes in the surface behaviors are attributed to the differences in the elemental properties, such as the attenuation length of x-ray photons. 相似文献
10.
S. Bollanti R. Cotton P. Di Lazzaro F. Flora T. Letardi N. Lisi D. Batani A. Conti A. Mauri L. Palladino A. Reale M. Belli F. Ianzini A. Scafati L. Reale M. A. Tabocchini P. Albertano A. Ya. Faenov T. Pikuz A. Oesterheld 《Il Nuovo Cimento D》1996,18(11):1241-1255
Summary A large-aperture, long-pulse XeCl excimer laser has been used to generate a soft-X-ray plasma source. Several laser optical
configurations have been employed to optimise X-ray emission, including positive-branch unstable resonators and injection
by seeding the gain region of the laser with a small commercial excimer laser, resulting in power densities in the range 1012–1014 W cm−2. The characteristics of the plasma source for each different laser configuration and for different target materials are investigated.
The most suitable source conditions (spectral energy distribution, time duration, etc.) for specific applications are discussed.
Supported by the Royal Society, UK.
Supported by INFM, Italy. 相似文献