Mirror smooth superconducting RF cavities by mechanical polishing with minimal acid use

Journal Article · Tue Feb 01 04:00:00 EST 2011 · Submitted to Supercond.Sci.Tech.

OSTI ID:1009186

Cooper, C A; Cooley, L D

A new mechanical technique for polishing the inside surface of niobium superconducting RF (SRF) cavities has been developed. Mirror-like finishes, the smoothest observed in cavities so far, were produced after fine polishing, with < 15 nm RMS roughness over 1 mm{sup 2} scan area. This is an order of magnitude less than the typical roughness produced by electropolishing. The processing equipment has advantages of modest installed and operating costs, simple associated technology, and no large quantities of acutely toxic chemicals or special handling procedures. Cavity quality factors above 10{sup 10} were maintained well above the 35 MV m{sup -1} benchmark for electropolished cavities, and this was achieved with an intermediate finish not as smooth as the final polish. Repair of a weld defect, which is intrinsic to this process, was also demonstrated. These transformational aspects could enable a new SRF cavity processing paradigm for future large scale particle accelerators such as the International Linear Collider.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL
• Sponsoring Organization: DOE Office of Science
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 1009186
• Report Number(s): FERMILAB-PUB-11-032-TD
• Journal Information: Submitted to Supercond.Sci.Tech., Journal Name: Submitted to Supercond.Sci.Tech.
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ACCELERATORS
Accelerators
BENCHMARKS
CAVITIES
ELECTROPOLISHING
LINEAR COLLIDERS
MECHANICAL POLISHING
MIRRORS
NIOBIUM
OPERATING COST
POLISHING
PROCESSING
QUALITY FACTOR
REPAIR
ROUGHNESS