This Small Business Innovation Research (SBIR) Phase I project proposes to investigate the feasibility of using hard ultra-smooth nanostructured diamond (NSD) for application in submicron thick X-ray windows. In terms of sorting metal scrap at high speed with a micron-thick film intermittently in contact with scrap, the film must be strong, hard, adherent, crack resistant, transparent to X-rays and structured on a submicron scale. Furthermore, applications in lithography-pattern stamps require similar rigorous abrasive wear on submicron sized features. The objective of this SBIR is to investigate NSD nucleation, strength, and X-ray properties in a thin, free-standing film. The research to be conducted is: the design of support grids for the growth of free-standing submicron NSD film, methodology of optimizing adherence on selected support grids, design of prototype X-ray window based on NSD film, and testing of NSD X-ray windows. The anticipated results of this SBIR research include the first NSD data on X-ray transparency, adherence, and the abrasive-wear properties of submicron film. The commercial value of hard, ultra-smooth, adherent NSD films in the submicron and nano- ranges is just now being explored. The need for micron and submicron films that have extreme properties can be immediately found in radiation windows and lithography-like tools subjected to abrasion and wear. Evidence of the commercial value is found in the wTe company support of this research for immediate application in X-ray windows. The application of these coatings and films find commercial value in that they extend life of products, reduce pollution, reduce energy use and facilitate efficient recycling. Each of these outcomes has specific, quantifiable positive effects for society