AVS 56th International Symposium & Exhibition
    Applied Surface Science Tuesday Sessions
       Session AS-TuP

Paper AS-TuP14
Surface Analysis of Electro-Polished Niobium Cavity-Samples for RF Applications

Tuesday, November 10, 2009, 6:00 pm, Room Hall 3

Session: Applied Surface Science Poster Session
Presenter: P.V. Tyagi, KEK, Japan
Authors: P.V. Tyagi, KEK, Japan
M. Nishiwaki, KEK, Japan
T. Saeki, KEK, Japan
M. Sawabe, KEK, Japan
H. Hayano, KEK, Japan
T. Noguchi, KAKEN Inc., Japan
S. Kato, KEK, Japan
Correspondent: Click to Email
The performance of superconducting RF cavities is restricted by the contaminations present on the surface and the surface roughness. In the recent years extensive research has been done to enhance the cavity performance by applying improved surface treatments such as mechanical grinding (MG), electro-polishing (EP), chemical polishing (CP), tumbling, etc followed by various post-treatment methods like ultrasonic pure water rinse, alcoholic rinse, high pressure water rinse, hydrogen per oxide rinse etc. Although EP post-treated by various methods has revealed good results to obtain smooth and clean surface, still more research and efforts are required in this area. Prior XPS (x-ray photoelectron spectroscopy) analysis of EPed Nb samples demonstrate that the surface was covered mainly with the niobium oxide (Nb2O5) along with carbon in addition, a small quantity of sulfur and fluorine was also found in SIMS (secondary ion mass spectroscopy) analysis even they were post-treated by various methods. In this article we present the analysis of surface contaminations and roughness for a series of EPed Nb samples located at various positions of a single cell Nb cavity followed by post-treatment methods and our endeavor to understand the performance of EP in a cavity with the help of surface analytical tools like XPS, SIMS and SEM (scanning electron microscope) at KEK.