Relativistic spherical plasma waves

Tightly focused laser pulses as they diverge or converge in underdense plasma can generate wake waves, having local structures that are spherical waves. Here we report on theoretical study of relativistic spherical wake waves and their properties, including wave breaking. These waves may be suitable as particle injectors or as flying mirrors that both reflect and focus radiation, enabling unique X-ray sources and nonlinear QED phenomena.Comment: 6 pages; 4 figure

Laser-driven high-power X- and gamma-ray ultra-short pulse source

A novel ultra-bright high-intensity source of X-ray and gamma radiation is suggested. It is based on the double Doppler effect, where a relativistic flying mirror reflects a counter-propagating electromagnetic radiation causing its frequency multiplication and intensification, and on the inverse double Doppler effect, where the mirror acquires energy from an ultra-intense co-propagating electromagnetic wave. The role of the flying mirror is played by a high-density thin plasma slab accelerating in the radiation pressure dominant regime. Frequencies of high harmonics generated at the flying mirror by a relativistically strong counter-propagating radiation undergo multiplication with the same factor as the fundamental frequency of the reflected radiation, approximately equal to the quadruple of the square of the mirror Lorentz factor.Comment: 8 pages, 5 figures. Presented at the ELI Workshop and School on "Fundamental Physics with Ultra-High Fields" 29.09.-02.10.2008, in Frauenworth Monastery, Bavaria, German

On extreme field limits in high power laser matter interactions: radiation dominant regimes in high intensity electromagnetic wave interaction with electrons

We discuss the key important regimes of electromagnetic field interaction with charged particles. Main attention is paid to the nonlinear Thomson/Compton scattering regime with the radiation friction and quantum electrodynamics effects taken into account. This process opens a channel of high efficiency electromagnetic energy conversion into hard electromagnetic radiation in the form of ultra short high power gamma ray flashes.Comment: 15 pages, 10 figures, invited talk presented at the SPIE-2013 conference, Prague, Czech Republic, Apr. 15, 201

Atomic and electronic structure of a copper/graphene interface as prepared and 1.5 years after

We report the results of X-ray spectroscopy and Raman measurements of as-prepared graphene on a high quality copper surface and the same materials after 1.5 years under different conditions (ambient and low humidity). The obtained results were compared with density functional theory calculations of the formation energies and electronic structures of various structural defects in graphene/Cu interfaces. For evaluation of the stability of the carbon cover, we propose a two-step model. The first step is oxidation of the graphene, and the second is perforation of graphene with the removal of carbon atoms as part of the carbon dioxide molecule. Results of the modeling and experimental measurements provide evidence that graphene grown on high-quality copper substrate becomes robust and stable in time (1.5 years). However, the stability of this interface depends on the quality of the graphene and the number of native defects in the graphene and substrate. The effect of the presence of a metallic substrate with defects on the stability and electronic structure of graphene is also discussed.Comment: 18 pages, 6 figures, accepted to Appl. Surf. Sc

Study of the structure of crater at the surface of 12Cr18Ni10Ti steel irradiated by high-power pulsed ion beam

The topography of surface layers of 12Cr18Ni10Ti (AISI 321) steel after pulsed high-power Cn+ ion beams irradiation was investigated by scanning electron microscopy. A thin foil was prepared from the cross section of a crater with the use of a focused ion beam in the column of a two-beam electron-ion microscope. The microstructure and chemical composition of the crater were studied by transmission electron microscop

Визначення переддефектного стану металоконструкцій об’єктів підвищеної небезпеки

В монографії проаналізовано причини виходу з ладу металоконструкцій об’єктів підвищеної небезпеки, викладено основні закономірності деградації матеріалу металоконструкцій, розглянуто сучасні магнітометрічні прилади для неруйнівного контролю металоконструкцій та описано прилад нового покоління для визначення переддефектного стану металоконструкцій об’єктів підвищеної небезпеки. Монографія може бути корисною широкому колу науковців та фахівців, які працюють з металоконструкціями і діяльність яких пов’язана з визначенням їх переддефектного стану та прийняттям рішення про продовження, або припи- нення експлуатації об’єктів підвищеної небезпеки

On the design of experiments to study extreme field limits

We propose experiments on the collision of high intensity electromagnetic pulses with electron bunches and on the collision of multiple electromagnetic pulses for studying extreme field limits in the nonlinear interaction of electromagnetic waves. The effects of nonlinear QED will be revealed in these laser plasma experiments.Comment: 7 pages, 3 figures, 1 table; 15th Advanced Accelerator Concepts Workshop (AAC 2012), Austin, Texas, 10-15 June, 201

Paleointensity determination on Neoarchaean dikes within the Vodlozerskii terrane of the Karelian craton

© 2017, Pleiades Publishing, Ltd. The results of paleomagnetic studies and paleointensity determinations from two Neoarchaean Shala dikes with an age of ~2504 Ma, located within the Vodlozerskii terrane of the Karelian craton, are presented. The characteristic components of primary magnetization with shallow inclinations I = −5.7 and 1.9 are revealed; the reliability of the determinations is supported by two contact tests. High paleointensity values are obtained by the Thellier–Coe and Wilson techniques. The calculated values of the virtual dipole moment (11.5 and 13.8) × 10 22 A m 2 are noticeably higher than the present value of 7.8 × 10 22 A m 2 . Our results, in combination with the previous data presented in the world database, support the hypothesized existence of a period of high paleointensity in the Late Archaean–Early Proterozoic

Effect of high-power ion beams on the surface topography and structure of the subsurface layer of sun microcrystalline titanium alloys

A rather homogeneous grain structure with equiaxial grains is formed for both alloys already after the effect of one pulse of the high-power ion bea