Влияние термополевой электронной эмиссии из катода с тонкой диэлектрической пленкой на эмиссионную эффективность пленки и напряжение зажигания таунсендовского газового разряда
The heat transfer process is simulated in a nano-sized cone-shaped cathode. A model of heat transfer is constructed using the phase field system and the Nottingham effect. We consider influence of the free boundary curvature and the Nottingham effect on the heat balance in the cathode.
The factors affecting the thermal degradation of a single silicon field-emission pointed cathode during the take-off of the emission current are described experimentally. The results of the numerical modeling of the temperature dynamics of the field-emission cathode in conditions of the presence of a free interface between the liquid and solid phases allowing for the surface tension are described.
A model of field electron emission from the metal cathode with a thin insulating film under the strong electric field, generated in the film by ions bombarding its surface in gas discharge, is developed. It takes into account tunneling of electrons from the electrode metal substrate into the insulating film, their motion in the film and going out of it into the discharge volume. An analytical solution of the onedimensional kinetic equation for the energy distribution function of emitted electrons in the film conduction band is found and an expression for the film emission efficiency equal to the fraction of emitted electrons, which escapes from the film and increases the cathode effective secondary electron emission yield, is obtained. It is demonstrated that calculated dependence of the emission efficiency on the electric field strength in the aluminum oxide film is in an agreement with experimental data for metal-insulatormetal tunneling cathodes. The proposed model can be used for investigation of an influence of the field electron emission from the cathode with a thin insulating film on its emission characteristics in gas discharge devices.
An approximate analytical expression for the ion current density near the cathode in glow discharge is obtained in the presence of a periodic relief of small amplitude and an insulating oxide film of varying thickness on its surface. It is found that ion focusing at the cathode sections with the minimum film thickness, located on any parts of the surface relief, takes place, resulting in an increase of the film thickness non-uniformity with time. Therefore, under the existence of an oxide film on the cathode, its sputtering in glow discharge is determined mainly by the film thickness non-uniformity and not by the surface relief.
The materials of The International Scientific – Practical Conference is presented below.
The Conference reflects the modern state of innovation in education, science, industry and social-economic sphere, from the standpoint of introducing new information technologies.
It is interesting for a wide range of researchers, teachers, graduate students and professionals in the field of innovation and information technologies.
The article examines the recent ‘schism’ in Eastern Orthodoxy to show how religion and politics are strongly intertwined in disputes over territory and sovereignty. It argues that two logics are at play in this conflict: one grounded in the theological‐political concept of ‘canonical territory’, the other in the notion of ‘communion’ at the basis of the Christian fellowship. The first is deployed in claims for national sovereignty as well as imperial domination, while the latter can make or break communities of faith. Drawing a parallel between the post‐socialist revival of religion in Ukraine and the current mobilization on the ground, it shows how these contradictory logics shape the fate of people, churches and states.
A Vikhr plasma-beam device of the Dense Plasma Focus (DPF) type with an energy of ~5 kJ has been recently put into operation at the Baikov Institute of Metallurgy and Material Science. The device, the design of its components, and its parameters are described. The physical processes that occur in the DPF working chamber during generation of beams of fast electrons, ions, cumulative jets of a hot plasma, hard X rays, and neutrons (if deuterium is used as a working gas) are considered. Experiments have been conducted with the aim of testing energy-saving DPF circuits using a new power supply circuit of the DPF chamber, which contains a crowbar gap and an electronic delay circuit. The device is used for testing, diagnosing, and modifying the radiation-thermal resistance of various materials intended for use in the thermonuclear power engineering and aerospace engineering. The first experiments with this device in radiation testing of materials and aerospace materials science are described.
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.