Моделирование возмущения бесстолкновительной плазмы поглощающим сферическим телом
A steady plasma state reached in the course of charging of an absorbing spherical body is found using computational methods. Numerical simulations provide complete information on this process, thereby allowing one to find the spatiotemporal dependences of the physical quantities and observe the kinetic phenomena accompanying the formation of stable electron and ion distributions in phase space. The distribution function of trapped ions is obtained, and their contribution to the screening of the charged sphere is determined. The sphere charge and the charge of the trapped-ion cloud are determined as functions of the unperturbed plasma parameters.
The conference was held in the form of lectures by leading scientists, oral and poster presentations of young scientists and students of physical specialties, as well as leaders of innovative structures for the purpose of mutual acquaintance with the new results of fundamental research on a wide range of areas in physics, the prospects and challenges in the expansion of relations between science , education and high technologies. SECTION (heads): I. LASERS (Fundam. Probl., Computer ...) (prof. A.A.Ionin) II. OPTICS (quant., And nano materials and new sources) (d.f.m.n.A.V.Masalov) III. Solid state physics, INCLUDING Nanostructures ELEM. BASE UNIT (Corresponding Member of RAS N.N.Sibeldin) IV. Nuclear physics, high energy physics (prof. O.D.Dalkarov, Head: Prof. V.A.Ryabov) V. PLASMA PHYSICS and particle beams (Head: Prof. A.V.Agafonov) VI. Astrophysics (Head: Prof. S.A.Bogachev) VII. PHYSICS IN THE MODERN INSTRUMENT AND TECHNOLOGY (prof. V.N.Nevolin)
We outline the history and development of the theory of thin current sheets in a collisionless space plasma from the early ideas of V L Ginzburg and S I Syrovatskii to the present day. We review the key achievements of the quasi- adiabatic theory, which provided insight into the fine structure of thin current sheets and enabled a comparison with experi- ment. This comparison showed the quasi-adiabatic approach to be more effective than the classical MHD approximation. With the development of the quasi-adiabatic theory in the last two decades, the existence of a number of new thin current sheet features, such as multi-scaling, metastability, and em- bedding, has been predicted and subsequently confirmed in situ; the role of individual particle populations in the forma- tion of the current sheet fine structure has also been investi- gated. The role of nonadiabatic effects in accelerating plasma beamlets interacting with current sheets is examined. Asym- metry mechanisms in thin current sheets in the presence of a magnetic shear component are described. A study is carried out of current sheet self-organization processes leading to the formation of a shear magnetic component consistent with currents flowing in the plasma. It is demonstrated that the ongoing development of the theory of thin current structures is a logical continuation of Syrovatskii's and Ginzburg's ideas on cosmic rays and reconnected current sheets in the solar corona.
We provide theoretical analysis of the reflectance of shock-compressed plasmas and warm dense matter for normal incidence of laser radiation as well as for the dependence of s- and p-polarized reflectivity on the incidence angle. The self-consistent approach for the calculation of the optical and electronic properties of warm dense matter and nonideal plasmas developed in our previous works is extended for the description of normal and polarized reflectivity from the broadened optically nonuniform medium. Two methods are applied for the calculation of the reflectivity from spatially broadened optically nonuniform medium. The first one is based on the solution of the Helmholtz equation for the amplitudes of the electromagnetic field. Another one is based on Drude theory of reflection. It allows us to calculate the ratio of the s- and p-polarized reflectivity if dependence of the dielectric function on distance is known. For the case of the polarized reflectivity, the particular attention is concentrated on the Brewster angle. The calculation results for the dielectric function, obtained within the framework of the density-functional theory with the longitudinal expression for the dielectric tensor, are applied for the calculation of the reflectivity. Comparison with the experimental data for shock-compressed xenon is performed.
Abstract—Within the axisymmetric MHD model of the solar wind, the magnetic field of the Sun has been analyzed in two phases of the solar cycle: the minimum activity, when the dipole magnetic field dominates and the maximum activity, when the quadrupole field predominates. It has been shown that during the period of maximum solar activity, the heliospheric current sheet acquires a conical shape and shifts to high latitudes up to 30° above the ecliptic plane. In the opposite hemisphere, at the same latitudes, a second current sheet of conical shape with an azimuth current of the opposite direction is established. It has been shown that the profiles of the main characteristics of the solar wind become steeper with distance from the Sun, and their amplitudes decrease, in this case, for the quadrupole field, the dependences of the main characteristics of the solar wind are more complex. A comparison of the results of the model with averaged characteristics of the solar wind shows a good match between the observed values and model parameters.
In Proceedings of the conference participants are presented on the following topics: 1) Lasers and Optics 2) Solid State Physics 3) Nuclear Physics 4) The generation and use of X-rays 5) Plasma Physics and particle beams 6) Astrophysics
Part IV of these Proceedings includes selected papers written on the basis of the best presentations of Sections 9 and 10 (“Design of Electron Component Base” and “Design of Radiation Tolerant VLSI Circuits and Components for Space Application”) of the VII All-Russia Science&Technology Conference “Problems of Advanced Micro- and Nanoelectronic Systems Development - 2016” (Moscow, Zelenograd, Oct. 03 – 07, 2016), in English. Materials of the Proceedings reflect the current state of the Russian micro- and nanoelectronics, methods and tools for development of micro- and nanoelectronic systems. The materials can be an important source of information to identify the promising areas of research and investments in the field of micro- and nanoelectronics. All the papers have been reviewed and approved by the Editorial Board of the Proceedings.
The dynamics of a two-component Davydov-Scott (DS) soliton with a small mismatch of the initial location or velocity of the high-frequency (HF) component was investigated within the framework of the Zakharov-type system of two coupled equations for the HF and low-frequency (LF) fields. In this system, the HF field is described by the linear Schrödinger equation with the potential generated by the LF component varying in time and space. The LF component in this system is described by the Korteweg-de Vries equation with a term of quadratic influence of the HF field on the LF field. The frequency of the DS soliton`s component oscillation was found analytically using the balance equation. The perturbed DS soliton was shown to be stable. The analytical results were confirmed by numerical simulations.
Radiation conditions are described for various space regions, radiation-induced effects in spacecraft materials and equipment components are considered and information on theoretical, computational, and experimental methods for studying radiation effects are presented. The peculiarities of radiation effects on nanostructures and some problems related to modeling and radiation testing of such structures are considered.