QUANTITATIVE MEASUREMENTS OF VAPORIZATION, BURST IONIZATION, AND EMISSION CHARACTERISTICS OF SHAPED CHARGE BARIUM RELEASES

Intensity-calibrated color video recordings of three barium-shaped cha rge injections in the ionosphere were used to determine the initial io nization, the column density corresponding to unity optical depth, and the yield of vaporized barium in the fast jet. It was found that the initial ionization at the burst was less than 1% and that 0% burst ion ization was consistent with the observations. Owing to the Doppler shi ft, the column density for optical thickness in the neutral barium var ies somewhat according to the velocity distribution. For the cases exa mined here, the column density was 2-5x10(10) atoms/cm2. This value, w hich occurred 12 to 15 s after release, should be approximately valid for most shaped charge experiments. The yield was near 30% (15% in the fast jet) for two of the releases and was somewhat lower in the third , which also had a lower peak velocity. This study also demonstrated t he applicability of the computer simulation code developed for chemica l releases by Stenbaek-Nielsen and provided experimental verification of the Doppler-corrected emission rates calculated by Stenbaek-Nielsen (1989).