Performance evaluation of 9 cell TESLA cavity for ILC

The International Linear Collider Technical Design Report (ILC-TDR) describes detail design for ILC and specifies to use TESLA 9 cell SRF cavity with ILC short beam pipe. At Superconducting RF Test Facility (STF) in KEK, the 9 cell TELSA-like cavities were developed and studied for the ILC. In 2015, four 9 cell TESLA cavities based on Euro-XFEL design were fabricated. This is the first time of fabrication by the domestic companies. Since the cavities are the same design of ILC-TDR except for one of beam pipe length, to evaluate RF performance using STF facilities and process is important for ILC. The procedure of 9 cell TESLA cavity processing and handling using the ILC recipe and the result of performance evaluation of one of 9 cell TESLA cavity are introduced and discussed in this report. (author)