Composites of Fiber-Reinforced Ultra Thin Films for X-ray Applications

Metalized polyimide films have become a standard for soft x-ray filters due to polyimide¿s strength and thermal stability. Utilization of polyimide support has led to increasingly larger and thinner filters, and throughput on missions such as the Chandra X-ray Observatory has been increased significantly. Newer missions such as Constellation-X require higher transmission across a large range of energies. To achieve greater transmission, next generation filters must look to even more advanced materials. The proposed innovation is to reinforce ultra-thin polyimide with extremely high strength materials such as Kevlar (polyaramid) or carbon fibers, to create a robust composite filter. At low x-ray energies (< 600 eV), the reinforcing fiber structure will have significantly higher transmission than the often-required metal mesh which it would replace. At higher energies above 3 keV, the Kevlar or carbon reinforcement will be nearly invisible, and improvements in mission throughput will be even more significant. In all cases it is expected that the increase in transmittance will be 10% or greater. The goal of this Phase I effort will be to show the feasibility of producing these types of composite materials for use in future x-ray astronomy missions and other Astrophysical Observing Systems