MgB2-Coated RF Cavities for Free Electron Laser Navy STTR FY2010.A Sol No.: Navy STTR FY2010.A Topic No.: N10A-T023 Topic Title: MgB2-Coated RF Cavities for Free Electron Laser Proposal No.: N10A-023-0614 Firm: Superconductor Technologies Inc. 460 Ward Drive Santa Barbara, California 93111-2310 Contact: Brian Moeckly Phone: (805) 690-4690 Web Site: http://www.suptech.com Abstract: Free electron lasers (FEL) made from Nb cavities offer high performance, but they are complex, bulky, and expensive. For Navy FEL applications, where footprint, power consumption, and cost are severely constrained and reliability is of great importance there is a critical need for an alternative to Nb. MgB2 is a recently discovered superconductor with a high critical temperature and critical field. These and other favorable materials properties suggest that MgB2-coated RF cavities have the potential to outperform Nb-based cavities in terms of operating temperature, size, cost, and complexity. This program's objective is to produce a conceptual design for an MgB2 thin film vacuum deposition chamber to enable fabrication of a proof-of-principle, MgB2-coated, pillbox-shaped cavity. In phase II of this program we will implement the design, and a suitable deposition chamber will be constructed. MgB2-coated pillbox cavities fabricated in this system will be tested at temperatures from 4.2 K to Tc and at high power. In this manner the feasibility of depositing non-flat high-quality MgB2 thin films on the inside of curved surfaces will be demonstrated, which is a crucial step in the implementation of the MgB2-RF-cavities concept for FEL applications. Benefits: Successful implementation and demonstration of our novel ideas for depositing MgB2 thin films on the inner surfaces of superconducting Nb RF cavities may represent a significant leap forward in this field by extending the existing fundamental limit of the performance of these cavities. Transition of this technology from an R&D environment to production would then be warranted, and STI's expertise with scale-up and high-volume manufacturing would be utilized. We envisage potential large-scale production of such cavities, perhaps in conjunction with companies such as AES, Inc. who are currently producing bare Nb cavities. Opportunities for commercialization exist for applications as diverse as FELs for military use, RF cavities for particle-physics accelerators, and for proton accelerators for detection of fissionable materials. Such opportunities represent a potential market of thousands of such RF cavities. Return