Suwada, T.

Paper	Title	Page
WEXMA01	Status of KEKB and Upgrade Plan to SuperKEKB	280
	M. Yoshida, T. A. Agoh, K. Akai, M. Akemoto, A. Akiyama, A. Arinaga, K. Ebihara, K. Egawa, A. Enomoto, J. W. Flanagan, S. Fukuda, H. Fukuma, Y. Funakoshi, K. Furukawa, T. Furuya, J. Haba, K. Hara, T. Higo, S. Hiramatsu, H. Hisamatsu, H. Honma, T. Honma, T. Ieiri, N. Iida, H. Ikeda, M. Ikeda, S. Inagaki, S. Isagawa, H. Ishii, A. Kabe, E. Kadokura, T. Kageyama, K. Kakihara, E. Kako, S. Kamada, T. Kamitani, K.-I. Kanazawa, H. Katagiri, S. Kato, T. Kawamoto, S. Kazakov, M. Kikuchi, E. Kikutani, H. Koiso, Y. Kojima, I. Komada, T. Kubo, K. Kudo, N. K. Kudo, K. Marutsuka, M. Masuzawa, S. Matsumoto, T. Matsumoto, S. Michizono, K. Mikawa, T. Mimashi, S. Mitsunobu, K. Mori, A. Morita, Y. Morita, H. Nakai, H. Nakajima, T. T. Nakamura, H. Nakanishi, K. Nakanishi, K. Nakao, H. Nakayama, S. Ninomiya, Y. Ogawa, K. Ohmi, Y. Ohnishi, S. Ohsawa, Y. Ohsawa, N. Ohuchi, K. Oide, M. Ono, T. Ozaki, K. Saito, H. Sakai, Y. Sakamoto, M. Sato, M. Satoh, K. Shibata, T. Shidara, M. Shirai, A. Shirakawa, T. Sueno, M. Suetake, Y. Suetsugu, R. Sugahara, T. Sugimura, T. Suwada, S. Takano, S. Takasaki, T. Takenaka, Y. Takeuchi, M. Tawada, M. Tejima, M. Tobiyama, N. Tokuda, S. Uehara, S. Uno, N. Yamamoto, Y. Yamamoto, Y. Yano, K. Yokoyama, Ma. Yoshida, S. I. Yoshimoto, K. Yoshino KEK, Ibaraki
	The KEKB is an electron-positron two-ring collider for the leading B meson factory. It consists of an 8 GeV electron ring (HER) and a 3.5 GeV positron ring (LER) and their injector linac. It has been operated since December 1998, and has recently marked the peak luminosity of 16.52 /nb/s. This peak luminosity is obtained under the crab-ready beam optics having the robust operating condition by some efforts to solve the optics problems. The integrated luminosity has also recently exceeded 1.2 /fb /day under the continuous injection mode. We are aiming more luminosity improvement after the crab cavity installation. Further the major upgrade plan for SuperKEKB is expected to achieve 400 /nb/s keeping the baseline of the original proposal and another upgrade plans are also considered towards over 1000 /nb/s based on the recent beam-beam simulation. This paper describes the recent status of KEKB and upgrade plans for SuperKEKB.
	Slides
THC2MA03	Design of L-band Superconducting Cavity for the Energy Recovery Linacs	570
	K. Umemori, T. Furuya, S. Sakanaka, T. Suwada, T. Takahashi KEK, Ibaraki H. Sakai, K. Shinoe ISSP/SRL, Chiba M. Sawamura JAEA/ERL, Ibaraki
	The ERL project in Japan has been started with the cooperation of?KEK, JAEA, ISSP and other SR institutes. For the ERL, superconducting cavities are key components to achieve high energy, high current and low-emittance electron beams. One challenging task, required for the cavity, is a strong damping of the higher-order-modes (HOMs), since they could cause the beam-breakup instabilities and the significant heat load on the cryomodule. We are proceeding with the cavity design, which is optimized for ERLs, with concentrating our attention on HOM damping. A large diameter beam-pipe with microwave absorber is adopted as HOM damping scheme. It can extract the HOM power effectively. We have also investigated optimization of the cavity shape for further suppression of the HOMs. In this report, our cavity design and its HOM characteristics are presented.
	Slides