Composite Vibration Isolation Support Structures with Low Thermal Conductivity

New accelerator systems for increasingly more demanding particle physics experiments are pushing the envelope in terms of energy and luminosity. In order to achieve the high energies required, perfect alignment of the accelerator’s superconducting RF cavities is critical. Ground motion and mechanical vibration caused by plant activities can adversely affect the beam alignment, thereby reducing the efficiency of the collider. These motions must be addressed, through a combination of mechanical vibration isolation and feedback systems in order to ensure the high level performance of facilities such as the Continuous Electron Beam Accelerator Facility (CEBAF) as well as at other DOE-sponsored and accelerator facilities. Cost savings can be realized through the incorporation of vibration damping composite structures with added cost savings arising from the improved thermal isolation arising from the low thermal conductivities characteristic of polymer matrix composites. The primary objectives of the Phase I work are to design and demonstrate thermally isolating composite support structure concepts with integrated vibration isolation capability for use in the upgraded cryomodules for the Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Jefferson National Accelerator Facility. Designs will build upon existing expertise in the design of cryogenic thermal isolation systems and will incorporate cryogenically compatible systems for vibration isolation. The utilization of advanced composite materials and an optimized structural design will provide superior performance relative to the current metallic supports. The overall goal is to design and demonstrate thermally isolating composite support structure concepts with integrated vibration isolation layers for use in construction of advanced facilities for Nuclear Physics research. The primary emphasis will be placed on developing designs for thermally isolating structures utilizing proven cryogenically compatible systems capable of vibration isolation. Activities contributing to this objective will include requirements verification, structure design and analysis as well as designs validation using experimental data from flat composite panels and full scale prototype structures. Advanced materials and designs will be produced for use as support structures in future nuclear physics research facilities under development by the U.S. Department of Energy. The products of this work will enable the fabrication of reliable systems with reduced operating costs. Commercial Applications and Other Benefits: The primary products of the proposed work are low thermal conductivity, vibration isolating fiber reinforced composite support structures. These structures will provide enhanced performance for both existing and future Superconducting Linear Accelerators in the US and abroad by reducing cryogenic losses and minimizing detrimental system vibrations. This support design, as well as the engineering design methods and materials can be used for similar structures for other nuclear accelerators under development by DOE.