The object of study is the processes of physical and technical processing of materials by intense energy flows and particles; the purpose of the study is to develop a scientific basis for the influence of highly concentrated fluxes of energy and particles on the structure and physical properties of thermoemitters to create high-emission thermoemitters designed to work in aerospace devices and modern technological devices; research methods – theoretical researches are based on provisions of the zone theory of semiconductors, for the analysis of a temperature field of a thermoemiter the thermal model of the cathode which works with continuous or pulsed selection of current of high density is applied, pulsed high-voltage breakdown of a small vacuum gap is considered in the framework of the anode mechanism, under the assumption of electromagnetic instability of the current in the substance carried into the interelectrode space by intense bombardment of the anode with electrons emitted directly by the cathode, experimental studies on modernized and specially manufactured equipment, study of the structure and composition of thermoelectric materials was carried out by the method of scanning electron microscopy with X-ray microanalysis, the work function of the electrons was determined by the method of full current, the erosion removal of the hollow cathode emitter material was controlled by low-temperature plasma optical emission spectrometry; the result is a created thermoemitters from materials in the system of barium-strontium hafnates with fine tungsten allow activation of emission properties outside the device, thermoemiters of directionally crystallized composite 60 wt. % GdB6–40 wt. % VB2 exposed to oxygen at a temperature of 1796 K is recommended for use in electron beam guns, for a thermoemiter made of barium zirconate with 40 wt.% tungsten in the temperature range 1500… 1850 K revealed an area of air pressure in which no poisoning is observed, a method for determining the dependence of the emission current on the anode voltage for a thermoemiter in pulse measurements has been developed, in which this dependence is restored on the basis of the measured dependences on the voltage time and the corresponding anode current response at the front and section of a rectangular high-voltage pulse; novelty – the regularities of changes in the composition, structure and emission properties of thermoemiters made of composite materials in the system of barium strontium hafnates with tungsten, which occur under the influence of high temperatures, pulsed electric fields, and oxygen-containing gases, have been studied and revealed, for the first time on their basis a new thermoemiter was created, which is characterized by an emission current density of 1040 A / cm2 at 1635 K, which is the largest for thermoemiters known in the world, the theoretical model for determining the emission characteristics of thermoemiters containing a semiconductor component of the donor type has been further developed within the band theory of semiconductors, it is established that when the emission current is selected, the surface layers acquire the greatest overheating, and not the surface itself, for the first time experimentally measured change in the temperature of the emitting surface during pulsed current collection with a pulse duration close to 10 μs, the pulsed penetration of a small vacuum gap was studied for the first time for the case when the source of the intense flow of primary electrons is directly the cathode itself, and current instabilities in the anode circuit preceding the breakdown were detected, and a physical explanation of the processes causing such instabilities was provided, for the first time to characterize the inhomogeneous emission capacity of the thermoemiter surface, the function of electron interception was proposed, the function is determined on the basis of experimental data, and in combination with the value of the emission current measured at deep saturation, allows in the model of a flat surface with two types of spots to determine the emission contrast of the surface and the surface fraction corresponding to these spots; degree of implementation – the results of the work were implemented at “Turbostal” LLC and used in the educational process of National Aerospace University “Kharkiv Aviation Institute”; scope of application – creation of high-emission thermoemitters designed to work in aerospace devices and modern technological devices of physical and technical processing.
