Saeki, T.

Paper	Title	Page
WEPMN026	Test Operation of Ball-Screw-Type Tuner for Low-Loss High-Gradient Superconducting Cavity in a Cryomodule	2104
	T. Higo, F. Furuta, Y. Higashi, T. Saeki, K. Saito, M. Satoh, H. Yamaoka KEK, Ibaraki
	We are constructing a Superconducting RF Test Facility (STF) at KEK as an R&D for ILC accelerator. In STF, four Low-Loss (LL) type 9-cell cavities will be installed into a cryomodule. We are developing ball-screw-type tuner for these cavities aiming at the accelerating gradient of 45 MV/m. At the end of 2006, we installed one LL 9-cell cavity dressed with the ball-screw tuner into the cryomodule. It will be operated without beam in 2007. This paper describes the results of the first operation of the ball-screw tuner for LL 9-cell cavity in the cryomodule of STF.
WEPMN047	Electro-polished Cavities Using China Ningxia Large Grain Niobium Material	2143
	Z. G. Zong, J. Gao, M. Q. Ge, Q. J. Xu, J. Y. Zhai IHEP Beijing, Beijing F. Furuta, H. Inoue, T. Saeki, K. Saito KEK, Ibaraki
	For the International Linear Collider (ILC), superconducting RF cavity technology was chosen. The superconducting cavity is made of polycrystalline niobium material so far. However, the material cost is high and the cavity performance has a rather scatter now. Large grain niobium (LG) cavity is an excellent idea because it simplifies the production process and results in less expensive. JLAB and DESY are pushing the R&D in last two years. KEK also has started to investigate LG. Three cavities with Ichiro shape were made of Chinese large grain niobium (Ningxia). A series of vertical tests has been carried out on several different surfaces treatment procedures by electropolishing. One cavity has reached the high gradient of more than 43 MV/m repeatedly. Other two cavities are still under testing. In this paper, the features of LG on electropolishing will be described with Ningxia large grain niobium material.
THOAKI03	Revision of Accelerating and Damping Structures for KEK STF 45 MV/m Accelerator Modules	2575
	Y. Morozumi, F. Furuta, T. Higo, T. Saeki, K. Saito KEK, Ibaraki
	KEK is constructing its superconducting RF test facility and installing 1.3 GHz superconducting accelerator structures. Learning from experience with our first 45MV/m 9-cell structures, we have revised accelerating structures as well as higher order mode dampers for improved performance. Problems found in the earlier structures are discussed and solutions are presented. New experimental results will be also reported.
	Slides