Thermodynamics of High Temperature Materials.

The research described encompasses five tasks each of which treats, from either an experimental or theoretical base, the measurement or interpretation of the high-temperature thermophysical behavior of model systems which show potential applications to the environmental resistant materials and the spacecraft survivability programs. Measurements have been completed, in a specially designed apparatus using state of the art pyrometery, on the triple point of graphite by a pulse heating method. Calculational algorithms bases have been expanded to calculate direct radiative interactions among many coupled channels and provide the continuum-continuum matrix elements needed to describe photodissociation phenomena. A combined theoretical and experimental program is being pursued to increase the understanding of the relationship of structure and reactivity of graphitic species. The rates and mechanism of ionic polymerization in highly unsaturated organic compounds, structures and thermochemistry of relevant ions, photodissociation of the polymeric ions, and the repair which generate polymeric ions after photodissociation have been studied. Development of apparatus and techniques to study the molecular basis for laser induced vaporization of refractory materials such as graphite continued.