卷 65, 编号 13 (2018)

The solution of the problem of disposing of human waste, including sewage sludge, is an important task of environmental technologies, which today use modern energy achievements, safe combustion, and energy utilization. The specific goal of the present work was the qualitative improvement of technologies of this kind, not so much for the sake of obtaining a large energy output but for the creation of an efficient, affordable, and ecologically perfect equipment based on advanced developments in the field of power generation on wet fuels. The possibility for successful implementation of new technologies is oriented towards the drying of moisture in organic materials and gasification of dried mass. The examples of new equipment are not yet experimentally tested.

A quantum-mechanical description of the theory of elastic scattering and a technique for determining the cross sections of particle interactions in plasma are described. An asymptotic solution of the Schrödinger equation for the elastic interaction of plasma particles is presented. Algorithms for determining phase shifts based on the Modified Effective Range Theory (MERT) are given. The Born approximation is considered to determine the amplitude of the scattered waves and the scattering cross section of the particles. Data are presented on the cross sections for scattering of electrons by atoms and ions in argon.

In the project of a modular submegawatt space-based thermionic NPP for the interorbital tug Gerkules, niobium alloy is used as the main structural material and isotopically pure lithium-7 is used as a coolant. To transfer lithium coolant, a series of electromagnetic induction pumps (EMP) have been designed, manufactured, and tested. The main requirement for EMPs is to ensure lithium transfer at high operating temperatures up to 900°C. This required high-temperature structural, magnetic, conductive, and electrical insulating materials. The design and technological features of the developed EMP are given. The tests were carried out in a pressure chamber as part of the lithium-niobium circuit simulating the NPP cooling system unit. The dependences of the EMP head-flow characteristics on the current strength and frequency, the temperature of transferred lithium, and other parameters are presented. The scatter of the same EMPs does not exceed 6%.

At present, the requirements for the lifetime of electric propulsion thrusters of spacecraft are growing. The article is devoted to the selection of material of the accelerating electrode that is the critical element of the ion thruster from the lifetime point of view. The accelerating electrode of the ion thruster is exposed to bombardment by charge-exchange ions, which cause its erosion. The rate of erosion depends on the ion-sputtering rate of the material from which the accelerating electrode is made. Graphite-based materials have the lowest ion-sputtering rate. The article considers the use of carbon–carbon composite material based on the Ipresscon^® carbon frame developed by OAO Kompozit as a material for manufacturing the ion thruster accelerating electrode. The results of calculation of erosion of such material and experimental verification of its application in the construction of the ion thruster are given in the article.

Primary approaches are considered for the development of emission simulators from electric propulsion thrusters (EPTs) in the radio-frequency range, including both the use of the stored actual member functions for the processes characterizing the EPT emission in the specified frequency ranges and the processes that are formed on the basis of emission simulation models. Various approaches to emission simulation modeling from stationary plasma thrusters are discussed. A possibility to use the earlier-developed mathematical models and software packages to simulate the EPT emission is considered; these models describe the complex envelope of the emission processes from a stationary plasma thruster in the given frequency ranges. Primary principles for the development of the radio simulators of the wanted signals and interference are also discussed. The application of multichannel vector generators is substantiated in view of the growth in complexity of simulated signals and interference. In such generators, the quadrature components of the processes describing EPT emission are employed that were obtained by test or by the simulation modeling methods. As an example, the simulator for EPT emission in the radio-frequency range is studied. This simulator provides such an electromagnetic environment in the given spatial region that takes various combinations of valid signals, thermal noises, and EPT emission into consideration. Recommendations are proposed on the use of the emission simulator as a part of the ground modeling complexes for defining possible influence of EPTs on onboard spacecraft systems.

Development of large spacecraft propulsion units involves the creation of high-temperature radiation-resistant systems for current conversion based on thermionic devices of plasma electric power engineering, such as grid-controlled switches and high-voltage plasma thermionic diodes (HVPTD). The current conversion system (CCS) is required to match the electrical parameters of a thermionic conversion power reactor (with an output voltage of 120–150 V) with the parameters of the electric jet engine (having a working voltage of hundreds or thousands of volts). This brings about an urgent issue of calculating the ignition voltage for the back-arc discharge in the interelectrode gap (IEG) of HVPTDs. A semiempirical correlation is proposed for predicting the back-arc discharge ignition voltage as a function of the cesium vapor pressure in IEG and the anode temperature. It can be used by designers of thermionic plasma power engineering devices.

A model of discharge for a radio frequency (RF) ion thruster with a flat induction coil is proposed. The configuration of magnetic fields and currents in 3D geometry is described. The skin layer boundary is determined by the condition at which the azimuthal current in plasma becomes zero under a transformer coupling with the inductor. Variation of radial magnetic field and azimuthal current at the generator driving frequency induces currents at the driving and second harmonic frequencies. Plasma becomes ionized due to magnetized collisional plasma electrons in mobile current layers. With operation at the optimal driving frequency, magnetic field of a definite sign fills the entire gas-discharge space in the course of convective diffusion within the current half-cycle. In the next half-cycle, it is filled with magnetic field of the opposite sign. Ohmic losses in the current layer are compensated in the course of field annihilation. The concentration of particles captured by the mobile layer was determined from the equality of “frosted” electron flows entering and leaving the layer in the course of single coulomb collisions with scattering at the pinch-angle. The azimuthal current of the fundamental harmonic component is determined by mobile layer currents outside the skin layer. The power losses are compensated by magnetic energy. The simulated results are compared with experimental data. The model of physical processes in radio frequency discharge with a flat induction coil has substantial peculiarities as compared with the discharge model using a cylindrical induction coil.