CLEANROOM TECHNIQUES TO IMPROVE SURFACE CLEANLINESS AND REPEATABILITY FOR SRF COLDMASS PRODUCTION

The Facility for Rare Isotope Beams (FRIB) and ReA linear accelerator projects at Michigan State University (MSU) utilize Superconducting Radio-Frequency (SRF) cavities for their accelerating structures. The structures are cleaned and assembled in a cleanroom to reduce particle contamination. The project requires more than 350 SRF cavities. In preparation for production we want to maximize repeatable processes and reduce work time. The cleanroom assembly group at MSU investigates process techniques performed in the cleanroom. Diagnostic tools, such as a surface particle counter, liquid particle counter, and airborne particle counter are used to quantify environments and optimize processes. Defined procedure specifications are necessary for cleaner, more repeatable processes. Storage options and cleaning processes are evaluated. The experiments are independent of cavity results and focus on creating the cleanest surface and environment in the most efficient manner. The experimental methods and results are summarized.