Chemical Reactions Kinetics with Metallic Atoms

摘要

The report describes research to develop a pulsed atomic beam by the laser vaporization of high velocity microparticles and to use the pulsed atomic beam to measure several metal monoxide formation cross sections. An experimental system for irradiating high velocity particles was designed, built, and tested. Tests confirmed that the particles were vaporized by the laser bombardment, but the thermal (random) velocity distribution of vaporized atoms and ions resulted in a much lower than anticipated useful beam intensity. As an alternative approach, the laser bombardment of solid metallic targets was used to produce both ionic and atomic pulsed beams. Useful beam intensities were obtained for both ions and atoms of uranium, thorium, aluminum, and iron. Generally, the entire energy spectrum was present in each pulse. Using time-of-flight techniques to specify the incident beam energy, cross sections for the reactions U(+) + O2 to UO(+) + O and Th(+) + O2 to ThO(+) + O were measured. (Author)