Hughes Aircraft Company

Microparticle Technology, Inc.

Jerg B Jergenson

Charles M McKenna

The preferred embodiment of the shielded counter-rotating spinner assembly for microparticalization of liquid consists of two opposed, coaxial, counter-rotating, conical, sharp-edged spinners whose edges are in close proximity and whose outer surfaces are in close proximity with non-rotating shields which extend to the edges of the spinners. The purpose of the shields is to greatly reduce the spinner induced air drafts so that, when liquids are applied to the inside surfaces of the spinners through the axes of the driving motors, the droplets produced on the edges of the spinners are injected into very low velocity air. The benefits of accomplishing this are the realization of very short droplet trajectories, the concomitant reduction in size of a plenum chamber which might encompass the device, the production of dense fogs of liquid droplets, and the ability to efficiently mix a liquid with a gas or to mix binary liquid chemicals together away from the device, but within a restricted volume where the atmosphere may be controlled and the production of solid droplets from the liquid phase through cooling in a finite volume and within a controlled atmosphere.

Shielded counter-rotating spinner assembly for microparticalization of

U-shaped billet (52) has a slot (54) cut therein for receipt of a slip of insulator material (56). This body is machined on its front end (64) to produce a narrow bridge (66) of controlled cross-sectional area. Emitter needle (78) is positioned in a bore through the bridge to be heated by current through the bridge. The ion emitter body is rigid and strong to hold the emitter needle in the proper location.

Liquid metal ion source

Billet (52) of electrically conductive or semi-conductive material has slot (54) therethrough which contains insulator slip (58). In this condition, the ion emitter body (44) is machined with the cylindrical exterior surface (60), conical nose (62) and emitter point (70). The limited electrical path localizes heating under the point (70) and the strong structure of the body permits strong mounting and controlled heat extraction.

A process for preparing a liquid metal ion source structure, preferably made from graphite, so that it may be wetted with boron-containing alloys. The process first involves the coating the source structure with elemental boron. The boron is preferably furnished as boron powder in a liquid carrier which may then be coated onto the surface of the source structure substrate. The coated structure is heated for a short time to a temperature whereat the source structure substrate and boron form a liquid layer at the surface of the substrate to 'boronize' the substrate. The final wetted source structure is achieved by mixing a small amount of free boron powder with the alloy to be ion evaporated (also in powdered form), coating the previously boronized source structure with this mixture and heating the contacted boron-augmented source alloy and source structure to a temperature of at least the solidus temperature of the source alloy, at which point the source structure is wetted. Once wetted, a flow of source alloy toward the emitter tip of the source structure can be established during operation of the ion source. Prior boronizing may be omitted for some boron carbide source structures.

Preparation of liquid metal source structures for use in ion beam

Liquid metal ion source has cylindrical ceramic tube 12 embraced by strip heater 20 which is held in place by ceramic bushing 26. Apex 28 of the strip heater contains the ion source fuel metal and is pierced by needle 34 having sharp tip 36. Upon heating and electrical bias with respect to a coaxial extraction electrode, tip 36 emits ions.

Liquid metal ion source has cylindrical ceramic body 12 engaged by one leg of hook shaped strip heater 20 which is held in place by ceramic bushing 24. Apex 18 of the strip heater contains the ion source fuel metal and is pierced by needle 22 having sharp tip 30. Upon heating by heater current flow through needle 22 and heater leg 14 and electrical bias with an extraction electrode, tip 30 emits ions.

Growing community of inventors

Santa Barbara, CA, United States of America

Jerg B Jergenson