Engineered Ceramic Composite Insulators for High Field Magnet Applications

72330S03-I High field magnets used in accelerators and fusion devices are subject to high mechanical loads at cryogenic temperatures. The end parts, pole pieces, spacers, and other insulator components must withstand these loads and be capable of surviving the high reaction temperatures of the superconducting coil. The currently used, coated metal parts are mechanically acceptable, but the fragile, insulating coating limits their reliability and increases magnet fabrication costs. This project will develop novel moldable ceramic insulators for use in accelerator and fusion magnets as end pieces, pole pieces, winding mandrels, spacers, and other components. Their electrical and mechanical strengths will be high, and their thermal properties will be tailored to meet the magnet specifications for niobium tin, niobium titanium, or even high temperature superconductor magnets. These ceramic insulators will withstand the high temperature heat treatments and will be radiation resistant. Phase I will fabricate near-net-shape ceramic pieces that can be mass-produced at moderate to low cost. Sample flat plate and hollow cylinder geometries will be made to simulate parts for common coil and cos-theta magnet designs. Characterization will include strength measurement, thermal expansion, and dimensional control. Commercial Applications and Other Benefits as described by awardee: The ceramic insulators should be more robust and reliable than current materials used in high field accelerator and fusion magnet systems. More robust insulators would lower magnet production costs, enabling future devices to be constructed within budgetary restrictions. Commercial magnets also could benefit from molded insulator components, increasing their reliability at lower cost.