Method for producing small hollow spheres
AssigneeThe United States of America as represented by the United States Department of Energy
InventorCharles D. Hendricks
Life of this patent
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Abstract
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.
Claims5
A method for producing small hollow spheres of uniform wall thickness and diameter comprising the steps of:
- forming drops from a solution of selected materials composed of sphere forming material and a blowing agent which decomposes at a certain temperature producing a gas agent, placing an electrical charge on at least a portion of the thus formed drops, passing the thus formed drops along a flow path through deflection electrode means wherein the drops having a certain electric charge are deflected from the flow path and separated from the remaining drops, passing the remaining drops through a multiple zone oven having an increasing temperature in each subsequent zone causing drying of the drops and forming same into hollow spheres by melting of the thus dried drops and thermal decomposing of the blowing agent such that a bubble is formed therein and expanded to form the sphere forming material into hollow spheres of substantially uniform wall thickness upon cooling.
Dependencies are inferred from the claim text.