The United States of America as Represented by the United States

The United States of America as Represented by the United States Energy

Ppg Industries, Inc.

University of Illinois

The United States of America as Represented by the Department of Energy

Charles D Hendricks

Robert J Turnbull

Christopher A Foster

Allan Rosencwaig

Jackson C Koo

A method for applying novel coatings to substrates is provided. The ends of multiplicity of rods of different materials are melted by focused beams of laser light. Individual electric fields are applied to each of the molten rod ends, thereby ejecting charged particles that include droplets, atomic clusters, molecules, and atoms. The charged particles are separately transported, by the accelerations provided by electric potentials produced by an electrode structure, to substrates where they combine and form the coatings. Layered and thickness graded coatings comprised of hithereto unavailable compositions, are provided.

Method of applying coatings to substrates

Method and apparatus (10) are provided for separating and classifying particles (48,50,56) by dispersing the particles within a fluid (52) that is upwardly flowing within a cone-shaped pipe (12) that has its large end (20) above its small end (18). Particles of similar size and shape (48,50) migrate to individual levels (A,B) within the flowing fluid. As the fluid is deflected by a plate (42) at the top end of the pipe (12), the smallest particles are collected on a shelf-like flange (40). Ever larger particles are collected as the flow rate of the fluid is increased. To prevent particle sticking on the walls (14) of the pipe (12), additional fluid is caused to flow into the pipe (12) through holes (68) that are specifically provided for that purpose. Sticking is further prevented by high frequency vibrators (70) that are positioned on the apparatus (10).

Particle separator

A method is provided for producing commercially large quantities of high melting temperature solid or hollow spherical particles of a predetermined chemical composition and having a uniform and controlled size distribution. An end (18, 50, 90) of a solid or hollow rod (20, 48, 88) of the material is rendered molten by a laser beam (14, 44, 82). Because of this, there is no possibility of the molten rod material becoming contaminated with extraneous material. In various aspects of the invention, an electric field is applied to the molten rod end (18, 90), and/or the molten rod end (50, 90) is vibrated. In a further aspect of the invention, a high-frequency component is added to the electric field applied to the molten end of the rod (90). By controlling the internal pressure of the rod, the rate at which the rod is introduced into the laser beam, the environment of the process, the vibration amplitude and frequency of the molten rod end, the electric field intensity applied to the molten rod end, and the frequency and intensity of the component added to the electric field, the uniformity and size distribution of the solid or hollow spherical particles (122) produced by the inventive method is controlled. The polarity of the electric field applied to the molten rod end can be chosen to eliminate backstreaming electrons, which tend to produce run-away heating in the rod, from the process.

Method for producing solid or hollow spherical particles of chosen

Large, uniform hollow spherical shells are produced by forming uniform size drops of heat decomposable or vaporizable material, evaporating the drops to form dried particles, coating the dried particles with a layer of shell forming material, and heating the composite particles to melt the outer layer and decompose or vaporize the inner particle to form an expanding inner gas bubble which expands the outer layer. By cycling the temperature and pressure on the hollow shells, spherical shells with uniform walls are produced.

Method to produce large, uniform hollow spherical shells

A method is provided for producing solid, evacuated microspheres comprised of hydrogen. The spheres are produced by forming a jet of liquid hydrogen and exciting mechanical waves on the jet of appropriate frequency so that the jet breaks up into drops with a bubble formed in each drop by cavitation. The drops are exposed to a pressure less than the vapor pressure of the liquid hydrogen so that the bubble which is formed within each drop expands. The drops which contain bubbles are exposed to an environment having a pressure just below the triple point of liquid hydrogen and they thereby freeze giving solid, evacuated spheres of hydrogen.

Solid evacuated microspheres of hydrogen

The disclosure is directed to a method for producing relatively uniform hollow spheres of a substance, the hollow spheres being formed with a gas therein as a result of the production process. The spheres, formed for example of hydrogen isotopes, are particularly useful as a fuel target for laser fusion applications. In accordance with the method of the invention, a jet of the substance of which the spheres are to be formed is provided in liquid form. Relatively uniform gas bubbles are injected into the liquid jet. In this manner, the bubbles break up or separate the liquid jet into relatively uniform hollow spheres of the substance, each with a bubble of the gas inside. The hollow spheres can be visualized as liquid droplets, each having a relatively uniform gas bubble therein. In accordance with a feature of the invention, a periodic mechanical disturbance, such as is obtained by exciting an ultrasonic transducer, is introduced to a gas stream, and tends to cause the gas stream to form relatively uniform bubbles within the liquid droplets.

Method for producing uniform spherical shells

A method and apparatus using cold gas jets for producing a substantially uniform layer of cryogenic materials on the inner surface of hollow spherical members having one or more layers, such as inertially imploded targets. By vaporizing and quickly refreezing cryogenic materials contained within a hollow spherical member, a uniform layer of the materials is formed on an inner surface of the spherical member. Basically the method involves directing cold gas jets onto a spherical member having one or more layers or shells and containing the cryogenic material, such as a deuterium-tritium (DT) mixture, to freeze the contained material, momentarily heating the spherical member so as to vaporize the contained material, and quickly refreezing the thus vaporized material forming a uniform layer of cryogenic material on an inner surface of the spherical member.

Cryogenic target formation using cold gas jets

A method for producing small hollow glass spheres filled with a gas by introduction of the gas during formation of the hollow glass spheres. Hollow glass microspheres having a diameter up to about 500.mu. with both thin walls (0.5 to 4.mu.) and thick walls (5 to 20.mu.) that contain various fill gases, such as Ar, Kr, Xe, Br, DT, H.sub.2, D.sub.2, He, N.sub.2, Ne, CO.sub.2, etc. in the interior thereof, can be produced by the diffusion of the fill gas or gases into the microsphere during the formation thereof from a liquid droplet of glass-forming solution. This is accomplished by filling at least a portion of the multiple-zone drop-furnace used in producing hollow microspheres with the gas or gases of interest, and then taking advantage of the high rate of gaseous diffusion of the fill gas through the wall of the gel membrane before it transforms into a glass microsphere as it is processed in the multiple-zone furnace. Almost any gas can be introduced into the inner cavity of a glass microsphere by this method during the formation of the microsphere provided that the gas is diffused into the gel membrane or microsphere prior to its transformation into glass. The process of this invention provides a significant savings of time and related expense of filling glass microspheres with various gases. For example, the time for filling a glass microballoon with 1 atmosphere of DT is reduced from about two hours to a few seconds.

Method for introduction of gases into microspheres

Method and apparatus for producing small hollow spheres of glass, metal or plastic, wherein the sphere material is mixed with or contains as part of the composition a blowing agent which decomposes at high temperature (T.gtoreq.600.degree. C.). As the temperature is quickly raised, the blowing agent decomposes and the resulting gas expands from within, thus forming a hollow sphere of controllable thickness. The thus produced hollow spheres (20 to 10.sup.3 .mu.m) have a variety of application, and are particularly useful in the fabrication of targets for laser implosion such as neutron sources, laser fusion physics studies, and laser initiated fusion power plants.

Method and apparatus for producing small hollow spheres

Method for producing small hollow spheres of glass, metal or plastic, wherein the sphere material is mixed with or contains as part of the composition a blowing agent which decomposes at high temperature (T .gtorsim. 600.degree. C). As the temperature is quickly raised, the blowing agent decomposes and the resulting gas expands from within, thus forming a hollow sphere of controllable thickness. The thus produced hollow spheres (20 to 10.sup.3 .mu.m) have a variety of application, and are particularly useful in the fabrication of targets for laser implosion such as neutron sources, laser fusion physics studies, and laser initiated fusion power plants.

Method for producing small hollow spheres

A light-weight, portable power pack for supplying a high voltage output to an electrostatic spray gun from a low voltage input is disclosed. The power pack is cylindrical in shape with an axial opening adapted to receive the discharge channels of the spray gun so that it may be mounted on and may form a part of the spray gun and is detachable therefrom for replacement purposes. The power pack comprises a power supply circuit including a square wave oscillator connected through a square-loop, tape-wound core transformer to a voltage multiplier network for converting a low voltage DC to a high voltage DC for induction charging of material discharged from the spray gun, the circuit being encapsulated in an epoxy resin material to provide a suitable mounting case therefor. The case is molded into a suitable shape and is attached to the front of the gun by means of screws, bolts, a bayonet type connection or other suitable fastening means, the power pack being provided with external contacts which serve to engage corresponding contacts on the spray gun to provide an electrical connection through the gun to the power source, which may be a battery pack carried by the operator, and to engage coresponding contacts on the inductive charging device for the spray gun. The power pack can form the forward barrel portion of the spray gun with the discharge channels extending through the center of the case, or can be incorporated into detachable accessories such as a gas shroud forming chamber mountable on the forward barrel portion.

Detachable cylindrical power supply for induction type electrostatic

Foam encapsulated laser fusion targets are made by positioning a fusion fuel-filled sphere within a mold cavity of suitable configuration and dimensions, and then filling the cavity with a material capable of producing a low density, microcellular foam, such as cellulose acetate dissolved in an acetone-based solvent. The mold assembly is dipped into an ice water bath to gel the material and thereafter soaked in the water bath to leach out undesired components, after which the gel is frozen, then freeze-dried wherein water and solvents sublime and the gel structure solidifies into a low-density microcellular foam, thereafter the resulting foam encapsulated target is removed from the mold cavity. The fuel-filled sphere is surrounded by foam having a thickness of about 10 to 100 .mu.m, a cell size of less than 2 .mu.m, and density of 0.065 to 0.6 .times. 10.sup.3 kg/m.sup.3. Various configured foam-encapsulated targets capable of being made by this encapsulation method are illustrated.

Growing community of inventors

Livermore, CA, United States of America

Charles D Hendricks