Ceramic and Cermet Targets

Abstract

Use of isotopic materials as targets in high temperature environments, e.g., reactor cores, requires that chemically stable forms of the isotopes be employed. Usually oxides are compatible with temperatures >1600 K, although some light element oxides exhibit some volatility at temperatures >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.

Research sponsored by the Division of Waste Products, U. S. Department of Energy, under contract W-7405-eng-26 with the Union Carbide Corporation.