Shibata, K.

Paper	Title	Page
MOOPMA05	R&D on Vacuum Components for High-Current Accelerators	41
	Y. Suetsugu, H. Hisamatsu, K.-I. Kanazawa, K. Shibata, M. Shirai KEK, Ibaraki
	In anticipation of coming high current accelerators era, R&D on various vacuum components has been carried out at KEK. Copper beam ducts with ante-chambers were designed to deal with the intense synchrotron radiation (SR) power density emitted from the high current beam. The ante-chamber structure is also effective to reduce photoelectrons around positron beam, which is helpful to suppress the electron cloud instability (ECI). A comb-type RF-shield was developed to reduce the beam impedance and improve the thermal strength compared to the conventional finger-type one, and applied to bellows chambers and gate valves. The connection flange with the same cross section to the beam duct was also developed in parallel. Novel structure of a movable mask (collimator) was recently proposed, which had lower impedance compared to the conventional one, and now the test model was under fabrication. The beam ducts, the bellows chambers, and the gate valves have been installed in the KEK B-factory (KEKB) positron ring for several years. The performance of these components has been studied during beam operation, and the promising results have been obtained.
	Slides
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