Changes in K-208 glass transmittance spectra under ionizing radiation and molecular fluxes
The effect of 40-keV electron and proton radiation with a flux density of 5 × 10 cm−2 s−1 on the deposition of products of thermostimulated gas release from a polymer composite on a substrate made from protective K-208 glass used for the protection of spacecraft solar panels is experimentally investigated. Analysis of the obtained results shows that, unlike proton radiation, electron radiation results in an increase in the optical density of the glass and stimulates the deposition of gas-release products. It is established that the majority of effects generated as a result of exposure of the substrate to electron radiation are neutralized by protons upon combined irradiation with electrons and protons.
Features of formation and migration of radiation-induced defects in carbon nanotubes (CNT) and nanostructured materials are examined. The main methods and software tools used for the simulating nanomaterial structure and space factors are described. The results of mathematical simulation are presented.
In this work we study influence of various factors on stability of ionizing radiation detectors installed in the cosmic ray spectrometer (SCR) based on diamond detectors of ionization radiation (DDIR). Diamond detectors for SCR are made of single crystals of synthetic diamond type IIa. Diamond detectors were studied successively in three different experiments. Checking detector stability with ambient temperature increased up to 70 degrees Celsius was the first experiment. At next we change the geometry of detector irradiation by rotating nuclear source around it and measuring changes in detector count rate. And last one experiment was about checking the phenomenon of polarization by prolonged detector irradiation by ionizing radiation of various types and energies. The study revealed the presence of the strong influence of the polarization effect on the work of diamond detectors for registration of ionizing particles with short mean free path (in our experiment they were the alfa-particles of 238Pu). In this work correspondence of the experimental results of the "rotation" the source around the detector with the data obtained by simulation in GEANT-4 was shown.
The problem of protecting humanity from the effects of electromagnetic and ionizing radiation (EMR and AI) is now becoming increasingly important, because The number of sources of EMP and AI increases and their capacities increase. In particular, the use of electronic means (computers, televisions, radiotelephones, office equipment, household appliances, etc.) is growing, and the number of people who have health problems associated with exposure to this type of radiation proportionately grows. Goes into the category of global problems facing humanity. The book consists of three sections. The first section is devoted to electromagnetic radiation produced by industrial installations and household appliances. In the second section, ionizing radiation of both natural and artificial origin is considered. The third section considers the nature of torsion fields. The influence of all these radiations on humans and biological objects is shown. The methods and means of measuring these impacts are described. Recommendations for protection against electromagnetic and ionizing radiation are given. The book can serve as a training tool for studying courses "Life Safety", "Technospheric Security", "Environmental Protection" in higher and secondary educational institutions. It can be useful to specialists involved in the design and operation of devices that can be sources of dangerous electromagnetic and radiation radiation, as well as for specialists in preventive medicine, labor protection services, etc
Electronic equipment of spacecraft is exposed to ionizing radiation of outer space, which is another reason for failure. Currently accepted to evaluate separately the reliability of electronic equipment and its radiation resistance, despite the fact that these phenomena are interrelated. The aim of the article is to estimate effects of ionizing radiation on the reliability of microwave devices, namely, the probability of failure-free operation of a microwave amplifier.
The probability of device failure model Q(t) for active lifetime is constructed as a product of the probabilities of failure Q1(t) - the probability of device failure due to set the total ionizing dose, Q2(t) - probability of failure of the device in the absence of exposure to ionizing radiation, Q3(t) - the probability of a single effect event. Probabilities Q2(t) and Q3(t) are valued at current normative documents. Probability Q1(t) is calculated based on probabilistic and physical models.
Research shows that, despite the high radiation resistance of microwave devices used in electronic equipment of spacecraft, when the long lifetime is required the low intensity radiation will have a tangible impact on the probability of failure. And that should be considered when designing equipment.
The report considers the issues of forecasting the reliability parameters of modern on-board equipment of spacecrafts. The expediency of using the results of tests of equipment and it’s components for resistance to the effects of ionizing radiation to predict the reliability parameters. Substantiated the possibility of alpha-time distribution for the MTBF prediction of reliability and durability of the CMOS integrated circuit. Shown the calculated ratios for estimating the probability of failure-free operation, the mean time between failure and minimum service life. Given possible ways of increasing the life of modern on-board equipment of spacecrafts by using specialized methods of protection against ionizing radiation of space. This study (research grant No 14-05-0038) was supported by The National Research University - Higher School of Economics’ Academic Fund Program in 2014.
Generalized error-locating codes are discussed. An algorithm for calculation of the upper bound of the probability of erroneous decoding for known code parameters and the input error probability is given. Based on this algorithm, an algorithm for selection of the code parameters for a specified design and input and output error probabilities is constructed. The lower bound of the probability of erroneous decoding is given. Examples of the dependence of the probability of erroneous decoding on the input error probability are given and the behavior of the obtained curves is explained.
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.
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.