HIGH-TEMPERATURE VAPORIZATION OF TRANSPLUTONIUM OXIDES

A systematic evaluation of the vaporization-decomposition behavior of the actinide oxides as a function of atomic number has been initiated. This work has provided important clues for understanding the underlyi ng roles played by the actinide's f-electrons in this process. Studies of the actinide sesquioxides have determined that the major factor in determining their primary mode of vaporization is the magnitude of di ssociation energies of the monoxides. It has been shown that the disso ciation energy of the monoxide is linked to the promotion energy of th e actinide element's f-electrons. Establishing this relationship has n ow provided both a predictive and a correlative approach to understand ing the vaporization processes of the actinide sesquioxides. Results f rom our initial vaporization studies of selected transplutonium sesqui oxides were found to be in accord with these predicted processes. This systematic correlation, recent information about the melting points o f berkelium and californium sesquioxides, and a summary of the initial high-temperature vaporization behaviors of several transplutonium ses quioxides are presented here.