Abstract: Bombarding a cesium heat pipe with high energy particles causes a spallation reaction which produces vapors of .sup.123 Xe and contaminants. The contaminants are removed in a dry ice cold trap while the .sup.123 Xe condenses in a liquid nitrogen trap where it decays to .sup.123.sub.I.

Abstract: A gas-lubricated thrust bearing employs relatively rigid inwardly cantilevered spokes carrying a relatively resilient annular member or annulus. This annulus acts as a beam on which are mounted bearing pads. The resilience of the beam mount causes the pads to accept the load and, with proper design, responds to a rotating thrust-transmitting collar by creating a gas film between the pads and the thrust collar. The bearing may be arranged for load equalization thereby avoiding the necessity of gimbal mounts or the like for the bearing. It may also be arranged to respond to rotation in one or both directions.

Abstract: Bombarding a cesium heat pipe with high energy particles causes a spallation reaction which produces vapors of .sup.123 Xe and contaminants. The contaminants are removed in a dry ice cold trap while the .sup.123 Xe condenses in a liquid nitrogen trap where it decays to .sup.123 I.

Abstract: An improved fluid seal for a rotating shaft is provided which includes an inner annular ring or runner adapted to be secured to the rotating shaft and a composite sealing ring which is keyed to the inner ring and includes a radial sealing surface. An outer, nonrotating, annular ring or housing which is concentrically disposed with respect to the runner and sealing ring, includes a radial sealing surface which sealingly engages the sealing surface of the sealing ring.A circular wave spring, which is anchored to the housing and is disposed between the composite sealing ring and a snap ring secured to the housing, provides an axial force which forces the two sealing surfaces into sealing contact. The waves of the spring act as individual hydrodynamic bearings, and the axial force is transmitted across an oil film. This eliminates rubbing contact and the need for a separate thrust bearing.

Abstract: A composite material is described which will provide low friction surfaces for materials in rolling or sliding contact and is self-lubricating and oxidation resistant up to and in excess of about 930.degree.C. The composite is comprised of a metal component which lends strength and elasticity to the structure, a fluoride salt component which provides lubrication and, lastly, a glass component which not only provides oxidation protection to the metal but may also enhance the lubrication qualities of the composite.

Abstract: The center-to-center spacings of a photoresist pattern for an array of holes applied to a thin metal sheet are increased by uniformly stretching the thin metal sheet in all directions along the plane of the sheet. The uniform stretching is provided by securely clamping the periphery of the sheet and applying an annular force against the face of the sheet, within the periphery of the sheet and around the photoresist pattern. The technique used in the construction of ion thruster grid units wherein the outer or downstream grid is subjected to uniform stretching prior to convex molding. The technique provides alignment of the holes of grid pairs so as to direct the ion beamlets in a direction parallel to the axis of the grid unit and thereby provide optimization of the available thrust.

Abstract: A process for the preparation and isolation of high purity anhydrous lower valence state metal halides comprising dissolving the corresponding higher valence state metal halide of the desired lower valence state metal halide in an organic liquid, which is selected such that the higher valence state metal halide is soluble therein and the lower valence state metal halide is insoluble therein, and subjecting the solution to high energy radiation which reduces the higher valence state metal halide to its corresponding lower valence state metal halide, at a temperature in the range of from about 0.degree.C. to about room temperature.

Abstract: Fused silicide coatings for protecting niobium alloy substrates are modified by providing dispersed nucleation sites in the form of discrete particles in the coating. The discrete particles have a thermal expansion coefficient lower than that of the fused silicide material. This alters the microstructure and reduces the thermal expansion coefficient of the coating so as to minimize the number of tensile cracks.