GENERATION AND PROPERTIES OF HIGH ALTITUDE CHEMICAL PLASMA CLOUDS
AIR FORCE CAMBRIDGE RESEARCH LABS HANSCOM AFB MA
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Physical or chemical techniques can be used to form localized regions of high electron density in the upper atmosphere. One method is described in detail wherein a mixture of cesium nitrate, aluminum powder, and a high explosive is detonated in the 90 to 120 km altitude region of the upper atmosphere. The partially ionized reaction products expand to form a cloud from which radio waves can be reflected or scattered. In night releases the free electrons are generated in the explosion by thermal ionization in day releases additional photoionization of cesium occurs by absorption of solar ultraviolet. The reflected radio signal duration and intensity are dependent on altitude, time of day, and wind shears. In addition to thermal ionization and photoionization, major factors in determining the usefulness of chemical plasma clouds for radio wave propagation are their size, structure, and orientation with respect to the transmission path.
- Atmospheric Physics