ALON® Components with Tunable Dielectric Properties for High Power Accelerator Applications

There are challenges in linear particle accelerators associated with the need to suppress “higher order modes” (HOMs). HOMs are detrimental to accelerator operation, as they are a source of beam instability. The absorption/suppression of HOMs and dissipation of the energy of higher order modes is vital to the function of these accelerators. A promising approach for suppressing HOMs requires the use of absorbers made of lossy ceramic components which absorb parasitic HOMs while transmitting the low-frequency fundamental RF signal. Surmet proposes to develop ALON based ceramic/metal composites to improve the performance of existing HOM absorbers, based upon its demonstrated ability to produce ALON® components with internal architecture. ALON® Transparent Ceramic has been measured to be a low loss material by Jefferson Labs. Using ALON as the matrix material, Surmet will add conductive fillers (e.g., metal powders, with known electrical characteristics at cryogenic temperatures) to produce ALON/metal composite components for beamline HOM absorbers. The process used will build upon Surmet’s robust manufacturing process for ALON® components, including those with internal architecture. Jefferson Labs will evaluate these components as potential HOM absorbers. Additional characterization such as residual strength of the composite material will be done by Surmet. Surmet proposes to transition its mature ALON® technology to process and fabricate highly robust and reliable ALON/metal composites to improve the performance of existing HOM absorbers in linear particle accelerators. Commercial Applications and Other Benefits: The emerging needs for particle accelerator absorbers include larger sizes, higher power capability, and spatially tailored RF absorbing performance at temperatures as low as 4K. Each of the DOE National Labs operates large particle accelerators that use large numbers of RF absorbing components. While this represents a significant market opportunity, a much larger market exists for such components in the areas of semiconductor processing and biomedical equipment. The semiconductor equipment market is estimated to be $40B per year. The market for absorbers that provide visual monitoring capability is expected to be large, estimated to be about $20-30M/year. Surmet estimates sales revenues of $10M during the first 10 years of commercialization of the products developed during the proposed SBIR effort.