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Title |
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| TPPP001 |
Design of Damping Ring for SuperKEKB
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773 |
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In the SuperKEKB, a plan upgrading the KEKB to higher luminosity of (2.5-5) x1035 cm2/sec, the beam currents are 9.4 A for the LER (3.5 GeV-electrons) and 4.1 A for the HER (8 GeV-positrons). In order to supply the HER with the positron beam, which is currently injected to the LER, the field gradient of the injector linac has to be increased. To meet this requirement, the S-band accelerating structures placed at the beam energy greater than 1 GeV, after the positron target, are replaced with C-band structures. A damping ring (DR) is indispensable since the aperture of the C-band structure is much smaller than the beam emittance. In this paper, we describe on the design of DR. We adopt a new cell structure for DR; FODO cell with alternating bends, where one of two bends in a cell is reversed. One of advantages of the proposed ring is that very small, even negative, momentum compaction factor is easily achieved by properly choosing the bend-angle ratio of the reverse bend to the main bend. Tracking simulation for the proposed DR has shown that it has very large dynamic aperture in both transverse and longitudinal phase space, for very wide tune space.
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| TPPP007 |
Recent Progress at KEKB
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1045 |
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- Y. Funakoshi, K. Akai, K. Ebihara, K. Egawa, A. Enomoto, J.W. Flanagan, H. Fukuma, K. Furukawa, T. Furuya, J. Haba, S. Hiramatsu, T. Ieiri, N. Iida, H. Ikeda, T. Kageyama, S. Kamada, T. Kamitani, S. Kato, M. Kikuchi, E. Kikutani, H. Koiso, M. Masuzawa, T. Mimashi, A. Morita, T.T. Nakamura, H. Nakayama, Y. Ogawa, K. Ohmi, Y. Ohnishi, N. Ohuchi, K. Oide, M. Ono, M. Shimada, S. Stanic, M. Suetake, Y. Suetsugu, T. Sugimura, T. Suwada, M. Tawada, M. Tejima, M. Tobiyama, N. Tokuda, S. Uehara, S. Uno, N. Yamamoto, Y. Yamamoto, Y. Yano, K. Yokoyama, M. Yoshida, M. Yoshida, S.I. Yoshimoto
KEK, Ibaraki
- F. Zimmermann
CERN, Geneva
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We summarize the machine operation of KEKB during past one year. Progress for this period, causes of present performance limitations and future prospects are described.
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| RPAE044 |
Operation and Recent Developments of the Photon Factory Advanced Ring
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2845 |
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- T. Miyajima, T. Abe, W.X. Cheng, K. Ebihara, K. Haga, K. Harada, Y. Hori, T. Ieiri, S. Isagawa, T. Kageyama, T. Kasuga, T. Katoh, H. Kawata, M. Kikuchi, Y. Kobayashi, K. Kudo, T. Mitsuhashi, S. Nagahashi, T.T. Nakamura, H. Nakanishi, T. Nogami, T. Obina, Y. Ohsawa, M. Ono, T. Ozaki, H. Sakai, Y. Sakamoto, S. Sakanaka, M. Sato, M. Satoh, T. Shioya, M. Suetake, R. Sugahara, M. Tadano, T. Takahashi, S. Takasaki, Y. Tanimoto, M. Tejima, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, N. Yamamoto, S. Yamamoto, S.I. Yoshimoto
KEK, Ibaraki
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The Photon Factory Advanced Ring (PF-AR) is a synchrotron light source dedicated to X-ray research. The PF-AR is usually operated at a beam energy of 6.5 GeV, but a 5.0 GeV mode is also available for medical application. In 6.5 GeV mode the typical lifetime of 15 hrs and the beam current of 60 mA with a single-bunch have been archived. Almost full-time single-bunch operation for pulse X-ray characterize the PF-AR. However, single-bunch high-current caused several problems to be solved, including the temperature rise of the some of the vacuum component, a pressure increase in the ring, and a sudden drop in lifetime. In order to avoid these issues the developments of new methods have been continued. In this paper, the status and the recent developments of the PF-AR will be presented. It concerns: the successful operation with two-bunch high-current in 5.0 GeV mode; varying the vertical beam size for the medical application; modulating the RF acceleration phase in order to elongate the length of bunch; stabilizing temperature in the ring tunnel; the study for medium emittance operation with 160 nmrad; moving the RF cavities in order to install a new insertion device; an innovative injection scheme using a pulsed quadrupole magnet.
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