释放不同化学物质对电离层扰动的比较

Comparison of Ionospheric Modification by Different Chemicals Release

在电离层F区释放氢(H_2)、水(H_2O)、二氧化碳(CO_2)、六氟化硫(SF_6)、三氟溴甲烷(CF_3Br)、羰基镍(Ni(CO)_4)可以损耗局域等离子体电子密度,形成电子空洞,电离层电子密度的改变主要取决于释放物质的气态分子与电离层之间的离子化学反应.在电离层人工主动扰动实验中,应根据发射成本和扰动效果对释放物质进行选择.通过热力学原理和有限元模拟方法计算比较了上述6种物质对电离层的扰动影响.计算结果表明,6种物质中水的气化率最低,约为19%,其余5种物质都在60%以上,选择密度小的物质,例如H_2和CO_2,可以有效降低发射成本.另外,扩散较慢且化学反应较快的物质,例如SF_6和Ni(CO)_4,能够使得电离层电子密度减少得更多,并且受扰动区域更广、持续时间更长.

Six chemicals, H2, H2O, CO2, SF6, CF3Br and Ni（CO）4, are considered as ionospheric modification materials. Each of these chemicals reacts in the F region to produce localized plasma depletions and form large scale electron holes. In the active ionospheric modification experiments, the criteria for selecting the released chemicals include the cost and effectiveness. The effectiveness of released chemicals depends on the amount which goes into the vapor state. In this paper, the thermo- dynamics governing the vapor fraction of the released chemicals were investigated. Additionally, the size and magnitude of the electron depletions were calculated with finite element simulation method. The results show that H2O has the lowest vapor yield of about 19% from a heated, pressurized tank, and over 60% of the other five chemicals should be vented in gaseous form. To reduce the cost, the chemicals with small density, such as H2 or CO2 density reduction, the chemicals which have slow such as SF6 or Ni（CO）4, may be selected. These durable electron hole. may be chosen. Based on estimating the electron diffusion speed and large chemical reaction rates, chemicals can produce a larger, deeper and more