Device for In-Situ Coating of Long, Small Diameter Tubes

Electron clouds in existing accelerators limit machine performance through dynamical instabilities and/or associated vacuum pressure increases. In addition, wall resistivity in accelerators causes ohmic heating and can lead to resistive wall instabilities. In situ coating of the stainless steel vacuum tubes with Cu and TiN could mitigate both of these problems. Therefore, this project will develop a robotic plasma deposition technique for in situ coating of long, small diameter tubes with copper and titanium nitride, in order to mitigate the problems of electron clouds and wall resistivity. The technique entails fabricating a robotic device comprised of staged magnetrons. In Phase I, an unbalanced magnetron sputtering device, configured for small radial dimensions, will be fabricated and operated to determine copper deposition rates. A planar titanium magnetron for titanium nitride deposition will be designed, and a preliminary design of the Phase II full-scale device will be developed. Commercial Applications and other Benefits as described by the awardee:In addition to mitigating the electron cloud and wall resistivity problems in accelerators, the technology should have applicability to the in situ coating of small diameter tubes and pipes in chemical, pharmaceutical, and other high purity material processing operations, improving product quality and extending the operational life of the process equipment.