LASER TYPE ULTRA-VIOLET RADIATION FEASIBILITY FOR LIGHTNING AND ATMOSPHERIC PROPAGATION STUDIES
Final rept., pt. 2
LIGHTNING AND TRANSIENTS RESEARCH INST ST PAUL MN
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The feasibility of a laser type ultra-violet source as a possible substitute for the continuously supported wire antenna, used for artificial atmospheric propagation studies and to trigger lightning for natural lightning channel studies, is considered. The energy required to produce an electron plasma or even a molecular plasma is quite high. A powerful laser beam would provide an intense concentration of energy. However, it is difficult if not impossible to produce lasers with wavelengths below the 1000 A required to ionize air molecules. Laboratory experiments were limited to the use of a 14 kilowatt carbon arc as a source in the far ultra-violet. No long spark diversion similar to that found with a jet plasma 10,000,000 to 100,000, 000 ionscc was observed with the carbon arc source. Methods of selective ionization to distribute the ions over the beam with just the density required for the conductivity of a jet plasma include possible rocket distribution of combustible particles to be ignited by a conventional laser beam for distances of several miles to produce islands of plasma which possibly could allow a discharge to propagate by the step by step process of the branch streamer mechanism.
- Atmospheric Physics