Novel methods for in-situ high-density surface cleaning (scrubbing) of ultrahigh vacuum long (~ 100 m or longer) narrow tubes to reduce secondary electron yield and outgassing

Electron clouds in existing accelerators limit machine performance through dynamical instabilities and/or associated vacuum pressure increases. Bare metal vacuum walls have shown to prevent electron cloud formation. Proper scrubbing of stainless steel, or copper vacuum walls (and even niobium) will mitigate the problems of electron clouds and increase accelerator luminosity. Intense non-magnetized plasma discharge cleaning technique is being developed for in-situ scrubbing of long, small diameter tubes. Proposed project entail s development of seed plasma and microwave injection for gene rating dense plasmas remotely in machines with difficult access. Develop plasma discharge cleaning methods for difficult to access long, narrow tubes. Set up experimental facility that simulates a cold-bore RH IC vacuum tube section, bellows and other components. Design and fabricate diagnostics to determine cleaning effectiveness. Perform discharge cleaning experiments and determine scrubbing effectiveness. In-situ discharge cleaning of existing accelerator vacuum tubes is a very cost-effective way to mitigate significant problems that exist in accelerators trying to increase luminosity. Advance to industry forefront an efficient plasma discharge cleaning method that can improve capabilities of automotive, semiconductor, chemical, pharmaceutical & other life-science industries, by improving deposition, etching and sterilization, in addition to cleaning.