The method for efficiently releasing samarium vapor to generate artificial plasma clouds in the ionosphere

Abstract

Vaporized samarium (Sm) has been released in the ionosphere for artificially creating plasma clouds, which can tailor radio propagation of information systems. The titanium-boron (Ti-B) self-propagating high-temperature synthesis (SHS) reaction can be used to vaporize Sm for releasing in the ionosphere. In this paper, a one-dimensional Fourier combustion model of Sm vaporizing by Ti-B reaction is established, based on the principle of chemical reaction and heat conduction. The Gauss-Seidel iterative algorithm is used to numerically simulate the SHS process of titanium-boron-samarium (Ti-B-Sm) system. This study first investigates the impact of different green compact porosity and content of Sm on the temperature field distribution, stable temperature and wave rate of the combustion process. The calculation shows that the porosity has little effect on the stable combustion temperature. With the increase of porosity, the stable combustion temperature remains basically unchanged, while the combustion wave rate shows a downward trend. The amount of Sm has a significant negative effect on the stable combustion temperature and the combustion wave rate. The higher the amount of Sm is, the more quickly the stable combustion temperature and the combustion wave rate decrease. The theoretical result indicates that, Sm could not exceed 35 % for being heated and vaporized. And the porosity could not exceed 52 % for efficient vaporization of Sm and stability of combustion wave. Finally, taking the Ti-B-Sm system with 30 % Sm contents as an example, several experiments were carried out using green compacts with different porosity. The experiments show that the maximum temperature of the compact during the combustion process is very close when the porosity varies from 30 % to 45 %, about 2075 K, which is in agreement with the simulation. The combustion wave rate is distributed from 5 mm/s to 8 mm/s within the range of 30 % and 50 % of porosity. Finally, the combustion products are detected by diffraction of X-rays (XRD), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). It shows that the Ti-B-Sm compact with 30 % Sm content and porosity not exceeding 52 % can effectively vaporize Sm, and the vaporization efficiency of Sm is about 75 %. The results of this study provide guidance for payloads of future experimental campaigns in the ionosphere.