75616-Superconducting radio frequency cavities, used in high energy accelerators, are produced by the sheet metal forming of multiple sections, which are then joined by high-vacuum, electron-beam welding. The welding procedures are very expensive and produce flaws and contamination that limit… More

75616B Superconducting radio frequency cavities, used in high energy accelerators, are produced by the sheet metal forming of multiple sections, which are then joined by high-vacuum, electron-beam welding. The welding procedures are very expensive and produce flaws and contamination that limit… More

The superconducting radio-frequency cavities being tested for use in the International Linear Collider are made from high purity niobium sheet metal, which has an inherent, performance-hindering "damaged layer." This surface layer is removed by acid treatments, which result in hydrogen… More

The Department of Energy is interested in the development of techniques to create a layer of niobium on the interior of a copper elliptical accelerator cavity, such as by energetic ion deposition, so that the resulting 700-1500 MHz structures have Q0>8 x 109 at 2K and so that overall fabrication… More

The ability of nuclear physics research to continue to make a significant impact on the scientific community relies on advances in accelerator performance, particularly on improvements in superconducting radio frequency (SRF) cavities. In order to obtain optimal performance, the inner surfaces of… More

The cost of corrosion for DoD has approached $20B per year. Naval aviation costs are about $5.4 billion/yr for corrosion related maintenance of aircraft and ships. Light-weight, high strength, aluminum alloys are used extensively throughout Navy aircraft, but require large repair and maintenance… More

The advancement of nuclear physics research relies on advances in accelerator performance, and much of that depends on improvements in superconducting radio frequency (SRF) cavities. While the operating gradients of niobium SRF cavities have increased from about 2 MV/m in the late 1970¿s to more… More

Al-Li alloys are of interest for use in aerospace structures due to the desirable combination of high strength and low density. However, high strength Al-Li alloys exhibit an intergranular delamination fracture mode which has limited widespread structural applications. Previous work at NASA LaRC,… More