scholarly journals Modeling of Processes in Plasma of Radio-Frequency Ion Injector with an Antenna Placed inside the Volume of Discharge Chamber

Aerospace ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 209
Author(s):  
Svyatoslav Gordeev ◽  
Stepan Kanev ◽  
Andrey Melnikov ◽  
Igor Nazarenko ◽  
Sergey Khartov

The work is devoted to the theoretical assessment of the efficiency increase possibility for the radio-frequency ion injector, which is designed for the contactless removal of space debris from near-earth orbit by using an antenna located inside the discharge chamber. Four internal antenna configurations and two external ones—end and side—are considered. Expected characteristics were estimated using an engineering mathematical model built in COMSOL Multiphysics using an approximate magnetohydrodynamic description of the charged particle behavior. According to the simulation results, the best characteristics can be obtained with an internal antenna with a conical arrangement of turns. Calculations showed that in some operating modes, such an antenna configuration makes it possible to halve the radio-frequency power consumption compared to the classical antenna located on the discharge chamber side surface. The performed theoretical study showed that the internal antenna can significantly increase the ion injector efficiency. In the future, verification of the obtained results by test is planned.

2020 ◽  
pp. 123-126
Author(s):  
В.В. Кожемякин ◽  
Р.А. Иванов ◽  
Е.С. Игнатьева

Работа посвящена расчетно-теоретическому исследованию работы блока инжекторов. Рассмотрен пароводяной струйный аппарат, который применяется в качестве средства циркуляции теплоносителя первого контура. Подвод дополнительного потока осуществляется на цилиндрическом участке с внезапным расширением сечения через перемычку. Для достижения поставленной цели разработана программа для ЭМВ, в которой смоделирована зависимость давления от нагрузки в контуре, а также проведено расчетно-теоретическое исследование влияние гидравлического сопротивления на расход перемычки. В данной работе рассмотрены только рабочие режимы, т.е. все инжекторы работают как насосы. В ходе работы было установлено, что при нагрузке в 30% увеличиваются коэффициенты инжекции пароводяного струйного аппарата, но характер работы перемычек не меняется. Так же было установлено, что расход через перемычку меняется не пропорционально коэффициенту гидравлического сопротивления перемычки. The paper is devoted to the computational and theoretical study of the injector block operation. A steam-water jet apparatus is considered, which is used as a means of circulating the primary circle coolant. The additional flow is supplied on the cylindrical section with a sudden expansion of the cross-section through the bridge. To achieve this goal, a computer program was developed that modeled the pressure dependence on the load in the circuit, and also a theoretical study of the influence of hydraulic resistance on the flow of the jumper was conducted. In this paper, only operating modes are considered, i.e. all the injectors function as pumps. In the process of the research, it was found that at a load of 30%, the injection coefficients of the steam-water jet apparatus increase, but the nature of the work of the jumpers does not change. It was also found out that the flow rate through the jumper does not change in proportion to the coefficient of hydraulic resistance of the jumper.


Nanoscale ◽  
2017 ◽  
Vol 9 (33) ◽  
pp. 11944-11950 ◽  
Author(s):  
Mehrdad Shaygan ◽  
Zhenxing Wang ◽  
Mohamed Saeed Elsayed ◽  
Martin Otto ◽  
Giuseppe Iannaccone ◽  
...  

Metal–insulator–graphene diodes are proved to be able to deliver high performance, and meanwhile are suitable for radiofrequency power detection.


1951 ◽  
Vol 4 (1) ◽  
pp. 51
Author(s):  
JV Hindman ◽  
AG Little ◽  
R Payne-Scott ◽  
DE Yabsley ◽  
CW Allen

On February 17 and 21-22, 1950, two exceptionally large radio-frequency disturbances of solar origin were observed on seven radio receivers working in the frequency range from 62 to 9400 Mc/s. At each of the frequencies the radio-frequency power flux was recorded continuously during the disturbance and at several frequencies the polarization of the radiation was examined. The apparent position of the origin of the radiation was determined at one frequency. The time of commencement and the duration of the disturbances at the different frequencies were compared with each other and with those of associated phenomena, solar flares, radio fade-outs, and geomagnetic effects. The two disturbances show marked similarities and marked differences ; these are summarized.


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