• K. Watanabe, H. Hayano, E. Kako, S. Noguchi, T. Shishido, Y. Yamamoto
  KEK, Ibaraki
• Y. Iwashita
  Kyoto ICR, Uji, Kyoto
• Y. Kikuchi
  Tohoku Gakuin University, Miyagi

Nine 1.3 GHz 9-cell superconducting cavities (MHI-01 ~ 09) for International Linear Collider (ILC) project were fabricated from 2005 to 2009 at KEK-STF. The vertical test (with temperature and X-ray mapping) and optical inspection using by high resolution camera system for nine cavities were carried out from 2006 to 2009 for STF Phase-I project and S1-Global project at KEK. The cavities were separated to three series. The first series is MHI-01 ~ 04 (fabricated at 2005). They were made the Centrifugal barrel polishing (CBP) at initial surface treatment. The second series is MHI-05 and 06 (fabricated 2008). The third series is MHI-07 ~ 09 (fabricated at 2009). The surface treatments of second and third series cavity were made only Electro Polishing (EP) process (without CBP), because of the EBW seams of equator and iris were improved by the feedback of optical inspection method. A good correlation has been so far observed between the hot spots localized by thermometry measurements in the vertical test and the positions of surface defects found by this system. The result of optical inspection will be reported in this paper.