Процессы радиационной электризации диэлектриков электронных средств в космической среде. Учебное пособие
Tyutnev A.P. T 98 The processes of electron charging of dielectrics the electronic devices in the space environment. Textbook. Mosk. State. Inst. of Electronics and Mathematics. M., 2012. 56c. ISBN 978-5-94506-336-5 We will discuss general patterns of occurrence of the electric fields in dielectrics electronic means in the space environment when they are irradiated by charged particles. Analyzes the electron charging of flat layers of polymeric materials, screen-vacuum thermal radiation, including gauze. The nature of electrostatic discharges occurring on board the spacecraft. Issued recommendations to improve the stability of the spacecraft to the impact of factors affecting discharges. The numerical analysis of the semi-empirical model of radiation conductivity of polymers. Designed for professionals involved in providing reliable electricity and radio components spacecraft, as well as students in related disciplines.
This paper describes modeling of spacecraft charging dynamics which is used in COULOMB-2 code in the case of spacecraft surface complex shape. The modeling of spacecraft charging is carried out via numerically solving the system of differential equations for time variations of local electric charge on every discrete element of the spacecraft surface. The presented computation results are obtained for spacecraft charging in hot magnetosphere plasma for several spacecraft design elements in a time interval of 20–10 000 s. The results are compared with the similar ones obtained with the NASCAP-2k and MUSCAT codes, and a good consistency was found.
In the paper, we discuss numerical modeling of spacecraft charging in geosynchronous orbit which was done using Coulomb-2, NASCAP-2K and SPIS codes, and present data obtained using the MUSCAT code too. The main distinctive features of the codes above are specified, description of the Coulomb-2 code is given in more details. We compare the results of calculations obtained for similar models of spacecrafts with identical surface materials and parameters of the space plasma environment. The possible reasons of divergence of the modeling results are discussed
Influence of electric field of charged spacecraft on secondary emission currents on the spacecraft surface is analyzed in terms of computation of secondary electron trajectories. Dependencies of the recollected electrons number on the electric field intensity at various distances from the emission point for standard secondary electron spectra are calculated. Criteria of the secondary electron emission suppression by the surface electric field which is applied for spacecraft charging modeling using the COULOMB-2 code are proposed. Modeling of the emitted electron trajectories in the electric field of the charged spacecraft having complex surface configuration enables to compute correction factors added to electric current balance equations (electron recollection).
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.
By using superconducting quantum interference device (SQUID) magnetometry, we investigated anisotropic high-field (H less than or similar to 7T) low-temperature (10 K) magnetization response of inhomogeneous nanoisland FeNi films grown by rf sputtering deposition on Sitall (TiO2) glass substrates. In the grown FeNi films, the FeNi layer nominal thickness varied from 0.6 to 2.5 nm, across the percolation transition at the d(c) similar or equal to 1.8 nm. We discovered that, beyond conventional spin-magnetism of Fe21Ni79 permalloy, the extracted out-of-plane magnetization response of the nanoisland FeNi films is not saturated in the range of investigated magnetic fields and exhibits paramagnetic-like behavior. We found that the anomalous out-of-plane magnetization response exhibits an escalating slope with increase in the nominal film thickness from 0.6 to 1.1 nm, however, it decreases with further increase in the film thickness, and then practically vanishes on approaching the FeNi film percolation threshold. At the same time, the in-plane response demonstrates saturation behavior above 1.5-2T, competing with anomalously large diamagnetic-like response, which becomes pronounced at high magnetic fields. It is possible that the supported-metal interaction leads to the creation of a thin charge-transfer (CT) layer and a Schottky barrier at the FeNi film/Sitall (TiO2) interface. Then, in the system with nanoscale circular domains, the observed anomalous paramagnetic-like magnetization response can be associated with a large orbital moment of the localized electrons. In addition, the inhomogeneous nanoisland FeNi films can possess spontaneous ordering of toroidal moments, which can be either of orbital or spin origin. The system with toroidal inhomogeneity can lead to anomalously strong diamagnetic-like response. The observed magnetization response is determined by the interplay between the paramagnetic-and diamagnetic-like contributions.
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.
This volume presents new results in the study and optimization of information transmission models in telecommunication networks using different approaches, mainly based on theiries of queueing systems and queueing networks .
The paper provides a number of proposed draft operational guidelines for technology measurement and includes a number of tentative technology definitions to be used for statistical purposes, principles for identification and classification of potentially growing technology areas, suggestions on the survey strategies and indicators. These are the key components of an internationally harmonized framework for collecting and interpreting technology data that would need to be further developed through a broader consultation process. A summary of definitions of technology already available in OECD manuals and the stocktaking results are provided in the Annex section.