New Concepts in Ionospheric Modification

Book excerpt: This report considers the ionospheric modification that can be produced by energetic charged particle and photon beams, which are emitted from a platform or vehicle (spacecraft or rockets) located in the ionosphere. The various beams considered include (1) charged particle beams composed of low, moderate, and high energy electrons, (2) beams of ions and plasma, and (3) photon beams of soft X rays and extreme ultraviolet radiation. Briefly considered, in addition to the beam topics, is the ionospheric modification produced by the release of neutral gas of high molecular weight from a rapidly moving vehicle such as the Space Shuttle Orbiter. When a ranking is made in terms of the new information that may be obtained, the scale of the modification that may be produced, and the availability of beam sources, ionospheric modification by means of relativistic electron beams appears particularly promising. However, all the methods have their own distinctive features which could make their use desirable under particular circumstances. The modification produced by means of beams of soft X rays, for example, is not strongly dependent on the beam's direction relative to the earth's magnetic field, and thus modification can be produced in regions inaccessible to a charged particle beam from the same vehicle. Keywords: Ionospheric modification; Particle beams; Electron beams; Photon beams; Plasma beams. (jhd).