SIMS analysis of high-performance accelerator niobium

Conference · Sat Nov 01 00:00:00 EDT 2014 · Surface and Interface Analysis

DOI:https://doi.org/10.1002/sia.5461· OSTI ID:1168948

Maheshwari, P. ^[1]; Stevie, F. A. ^[1]; Myneni, Ganapati Rao ^[2]; Rigsbee, J, M. ^[1]; Dhakal, Pashupati ^[2]; Ciovati, Gianluigi ^[2]; Griffis, D. P. ^[1]

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1. NCSU
2. JLAB

Niobium is used to fabricate superconducting radio frequency accelerator modules because of its high critical temperature, high critical magnetic field, and easy formability. Recent experiments have shown a very significant improvement in performance (over 100%) after a high-temperature bake at 1400 degrees C for 3h. SIMS analysis of this material showed the oxygen profile was significantly deeper than the native oxide with a shape that is indicative of diffusion. Positive secondary ion mass spectra showed the presence of Ti with a depth profile similar to that of O. It is suspected that Ti is associated with the performance improvement. The source of Ti contamination in the anneal furnace has been identified, and a new furnace was constructed without Ti. Initial results from the new furnace do not show the yield improvement. Further analyses should determine the relationship of Ti to cavity performance.

• Research Organization: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 1168948
• Report Number(s): JLAB-ACC-14-1928; DOE/OR/23177-3285
• Journal Information: Surface and Interface Analysis, Vol. 46, Issue S1; Conference: Nineteenth International Conference on Secondary Ion Mass Spectrometry, SIMS XIX, Jeju, Korea, September 29–October 4, 2013
• Country of Publication: United States
• Language: English