Ceramic and cermet targets

Use of isotopic materials as targets in high temperature environments, e.g., reactor cores, requires that chemically stable forms of the istopes be employed. Usually oxides are compatible with temperatures greater than or equal to 1600 K, although some light element oxides exhibit some volatility at temperatures greater than or equal to 1300 K. Especially in the case of heavy elements, the relatively low melting points of the metals, poor compatibility of the metals with encapsulation materials, and high chemical reactivity at moderate temperatures preclude the use of metal targets. However, encapsulation of ceramic targets has been successfully performed yielding high integrity samples. If hydrogen-reducible metals are mixed with the isotope(s), malleable, high strength, corrosion resistant targets can be rolled which contain a ceramic phase of isotope oxide. Isotope dilutions, additions of metals to form the metal matrix of a cermet target, and subsequent homogenization of all components are performed by dissolution in molten urea followed by calcination and compaction into the desired target form