Chemical Vapor Composites Silicon Carbide for Radiation Hard Optics

Trex proposes to continue development of a radiation hard optical coating for CVC silicon carbide through refinement of the Phase I coating designs and through validation testing. Design optimization for high reflectivity/low emissivity in the IR region will be achieved through establishment of detailed requirements and thin film design. Trex proposes to continue an iterative design and thermal modeling approach established in Phase I that successfully identified several viable designs based on a protected silver basecoat with multi-layered dielectric stacks. Optical coating performance analysis will be conducted using the Essential Macleod software and survivability will be assessed using the PUFF-TFT thermal conduction hydrocode and classified nuclear threat spectra. Subsequent to a design review, optics grade CVC silicon carbide coupons will be coated with approved deposition prescriptions. Coatings will be characterized in terms of manufacturabilty, optical performance (reflectivity & BRDF characterization), durability (MIL-F-48616 testing) and storage life (accelerated life testing). Coatings meeting optical performance requirements will exposed to physical x-ray fluence levels representative of an actual threat environment at the Double Eagle test facility in San Leandro, CA.