*** 9760379 Wallmark This Small Business Innovation Research Phase I project will investigate electrically conductive synthetic diamond as a base material for high performance, ultra-fine beam controlling and spot size defining apertures. Scientific, industrial, commercial, medical and military instruments employing electron and other particulate beams require beam defining and controlling apertures. Historically, these apertures have been made of platinum, molydenum, tungsten or metal foil. When apertures less than 10 microns are bombarded with high particulate densities in vacuum, they limit system performance. Limitations include: reduced beam currents to prevent 1) aperture base material meltdown and 2) spot size degradation due to erosion and/or feathering of the aperture. Metal aperture manufacturing technology cannot produce apertures smaller than 10 microns with tolerances of typically +/-0.2 microns that can withstand high density particulate bombardment. While the proposer has demonstrated the feasibility of using gold coated, nonconductive diamond as a base material, the comparatively fragile conductive coating reduces the dimensional integrity and lifetimes of these apertures. Knowledge gained will improve aperture performance and reliability, resulting in higher resolution, higher throughput, and greater reliability of electron and other particulate beam systems. This knowledge will also lead to the development of an innovative material technology for apertures having important commercial value in many diverse fields. The successful completion of this phase will lead to the evolution of an innovative material technology for apertures having commercial value to the electronic imaging instrument industry and other industries requiring chemically inert, ultra-fine apertures capable of withstanding repeated bombardment of high particulate emissions densities, thermal cycling and exposure to atmosphere without degradation. Typical among these industries are sate llite reconnaissance imaging, aerospace instrumentation, medical imaging, CD mastering, optical digital storage, cinematography, printing and publishing, cartography and micro-machining. ***