Novel Silica Aerogel Panels as Radiators for Cherenkov Detectors

75351-Aerogels, with their low refractive index and reasonably high light transmission, would be highly desirable Cherenkov detectors in high-energy particle detection. Unfortunately, when aerogels are used as Cherenkov radiators, there are some disadvantages: medium to low light transmission in the UV-visible wavelength region, low moisture resistance, difficulty in fabricating large size panels, and extreme fragility. This project will establish the chemistry of transparent aerogels and develop process parameters for producing large size, thick aerogel panels. This would eliminate the need for stacking tiles within the array of Cherenkov detectors, significantly decreasing the number of tiles and thereby improving the accuracy of particle separation and detection. In Phase I, an improved silica aerogel, will be fabricated for use as a radiator for Cherenkov detectors. The aerogel will have high light transmittance (~ 80%) at 400 nm, durable hydrophobicity, and a high degree of flexibility and resiliency. Also, the feasibility of producing 5 cm thick aerogel panels having the properties described above will be demonstrated. Phase II will produce aerogel panels for a number of nuclear physics facilities, which are in early stages of development. Commercial Applications and Other Benefits as described by the awardee: The aerogels should be very useful not only for Cherenkov detection but also for applications that would significantly save energy and protect the environment ¿ extra-high-R-value window glazing, insulated translucent building panels, and skylights.